EMC VNXe DATA PROTECTION · VNXe Data Protection ... and folders from Linux/UNIX hosts located on a network. ... coordinates the entire data replication process from discovery and

White Paper

Abstract

This white paper details the integrated features that can be positioned for business continuity in the EMC® VNXe™ series platforms. Data protection features include snapshots, replication, and NDMP backups. January 2013

EMC VNXe DATA PROTECTION Overview

2 EMC VNXe Data Protection – Overview

Copyright © 2013 EMC Corporation. All Rights Reserved. EMC believes the information in this publication is accurate as of its publication date. The information is subject to change without notice. The information in this publication is provided “as is.” EMC Corporation makes no representations or warranties of any kind with respect to the information in this publication, and specifically disclaims implied warranties of merchantability or fitness for a particular purpose. Use, copying, and distribution of any EMC software described in this publication requires an applicable software license. For the most up-to-date listing of EMC product names, see EMC Corporation Trademarks on EMC.com. Part Number h8219.4


Table of Contents

Executive summary.................................................................................................. 4

Audience ............................................................................................................................ 4

Terminology ............................................................................................................ 4

VNXe Data Protection .............................................................................................. 6

EMC Replication Manager Overview ......................................................................... 6

Snapshots .............................................................................................................. 6

Shared Folders and NFS datastore snapshots ..................................................................... 8

iSCSI snapshots ................................................................................................................. 9

Protection Storage ................................................................................................. 10

Scheduling ....................................................................................................................... 16

Replication ............................................................................................................ 17

Managing replication sessions ......................................................................................... 19

Synchronization Frequency ............................................................................................... 20

Replication Session Operations ........................................................................................ 21

VMware vCenter Site Recovery Manager ........................................................................... 24

Backup and Recovery Operations ........................................................................... 25

NDMP Backup .................................................................................................................. 25

Self-Encrypting Drives ............................................................................................ 27

Conclusion ............................................................................................................ 27

References ............................................................................................................ 28


Executive summary A small to medium sized organization’s data is one of its most valuable assets. Therefore, the company’s highest priorities must include safeguarding its data. EMC® VNXe™ Series provides integrated features for customers to meet their goals of business continuity and data protection. This white paper describes the relevant technologies for different business continuity and data protection situations.

Customers are concerned about data availability at all times. Outages, whatever the cause, are extremely costly. Further, data outages affect customers of all sizes. Systems and storage administrators have become aware of the importance of data availability while dealing with shrinking IT budgets. The difficulty they face is in deciding which technology to apply to their situation.

While considering data protection tools, customers must evaluate which aspect of data protection they need. Is security of data and risk mitigation needed? Do they need highly available data during normal business operations, so that the failure of a device does not affect the availability of their business function? Or, do they need data backup and recovery? All these aspects constitute the overall umbrella of business continuity and data protection.

Audience

This white paper is intended for EMC customers, partners, and employees looking to understand features that exist in the EMC VNXe product that can provide maximum data availability.

Terminology • Common Internet File System (CIFS) – An access protocol that allows users to

access files and folders from Windows hosts located on a network. User authentication is maintained through Active Directory and file access is determined by directory access controls.

• EMC VNX Storage Replication Adapter for VMware Site Recovery Manager – EMC VNX Storage Replication Adapter (SRA) is a storage replication adapter that extends the disaster-restart management functionality of VMware SRM to the EMC VNX storage environment.

• EMC VNXe Enabler for VNX Storage Replication Adapter – EMC VNXe Enabler for EMC VNX SRA (VNXe Enabler) specifically enables VNX SRA to manage EMC VNXe series systems during disaster recovery.

• iSCSI protocol – The iSCSI (internet small computer system interface) protocol provides a mechanism for accessing raw block-level data storage over network connections. The iSCSI protocol is based on a network-standard client/server model with iSCSI initiators (hosts) acting as storage clients and iSCSI targets


acting as storage servers. Once a connection is established between an iSCSI host and the iSCSI server, the host can request storage resources and services from the server.

• iSCSI server – A VNXe server that uses the iSCSI protocol to manage Microsoft Exchange storage groups, generic iSCSI storage virtual disks, Hyper-V datastores, and VMFS-based VMware datastores.

• Local replication – Local replication occurs between two storage resources on the same storage server or two different storage servers within the same VNXe system. After the local replication session is established, a read-only copy of the source storage resource is created on the destination storage server.

• Network Data Management Protocol (NDMP) – A standard for backing up file servers on a network. It allows centralized applications to back up file systems running in a customer environment.

• Network File System (NFS) – An access protocol that allows users to access files and folders from Linux/UNIX hosts located on a network.

• Network-attached storage (NAS) – File-based storage for a wide range of clients and applications that access storage over network connections. Protocol-specific file systems are located and managed on the storage system, which transfers data to hosts over TCP/IP using CIFS and NFS file sharing protocols.

• Remote replication – The replication of stored data from one VNXe system to another (remote) VNXe system or VNX/Celerra® system.

• Self-Encrypting Drives (SEDs) – A disk drive that encrypts data as it is stored to protect it from theft, hardware loss, and attempts to read the disk directly by physically deconstructing the drive. Data stored on a SED requires an authentication key for decryption and access.

• Shared Folder server – A VNXe server that uses either the CIFS or NFS protocol to catalog, organize, and transfer files within designated shares. A shared folder server is required to create shared folders that contain CIFS or NFS shares, or NFS VMware datastores.

• Snapshot – A read-only, point-in-time copy of data stored on the storage system. Administrators can recover files and folders from snapshots.

• Storage resource – An addressable and configurable storage instance associated with a specific quantity of storage, storage server, storage pool, and protocol (iSCSI or NAS).

• Unisphere™ – A Web-based management interface for creating storage resources, configuring and scheduling protection for stored data, and managing and monitoring other storage operations.

• VMware vCenter Site Recovery Manager – VMware vCenter Site Recovery Manager (SRM) leverages storage-based replication to help you manage your disaster recovery process.


Standard Provisioning – The amount of storage requested for a storage resource is exclusively allocated for it. This storge is reserved, and the unused portion cannot be used or distributed among other storage resources associated with the same storage pool.

Thin Provisioning – The amount of storage requested for a storage resource is not immediately allocated for it. Instead, Unisphere allocates an initial quantity of storage to the storage resource, and then increments this quantity, up to the requested amount, when the percentage of storage used reaches a particular threshold.

VNXe Data Protection Data protection for the VNXe is summarized in three categories: snapshots, replication, and traditional NDMP backups. The various application-aware capabilities may add application knowledge and custom functionality but are still based on the basic network-attached storage (NAS) and iSCSI protection concepts. VNXe includes data protection functionality that revolves around the concepts of protection and recovery for shared folder, application, or generic iSCSI storage. EMC Replication Manager (RM) is leveraged for iSCSI data protection.

EMC Replication Manager Overview Replication Manager manages EMC point-in-time replication technologies and coordinates the entire data replication process from discovery and configuration to the management of multiple disk-based replicas. This enables organizations to meet service-level agreements for reduced recovery point objectives (RPOs) and recovery time objectives (RTOs). Running on a separate Microsoft Windows server, it provides a graphical user interface for managing the replication and snapshots of iSCSI storage.1

Snapshots

A snapshot is a virtual point-in-time image of the data within a storage resource. Snapshots provide a record of the content in the targeted storage resource at a particular date and time, but they are not full copies of the data. Periodically creating snapshots of a storage resource provides an effective technique for meeting data protection and recovery requirements. Based on the importance and volatility of data within a VNXe storage resource, you can define recurring schedules that specify times and intervals for VNXe snapshot operations.

VNXe provides tools for performing manual (on-demand) snapshots, configuring snapshot schedules, and performing snapshot restore operations and snapshot recovery operations.

1 Snapshots created with Replication Manager can be viewed and deleted in Unisphere.


You can choose default or customized snapshot schedules that specify regular time intervals to perform snapshot operations (automatic snapshot creation and deletion). You can select the interval, times, days, and dates at which snapshot operations occur. A collection of rules within the schedule specifies the interval, frequency, and time that snapshots are taken. VNXe calculates the amount of storage protection space needed based on whether the protection schedule is enabled by the administrator. This value can be adjusted if desired.

The VNXe system also enables you to manually create snapshots that contain on-demand images of specific storage resources at a particular time. You can create a manual snapshot by navigating to the Snapshots tab in the Details page of the given storage resource, and clicking the Take Snapshot Now button (shown in Figure 1). This feature is useful in various situations, such as taking snapshots of data that will be unavailable for a period of time, that will be subject to unusual circumstances or risks, or that is used for testing or debugging purposes.

Figure 1: Manual snapshot of the storage resource

When you need to restore a VNXe storage resource to its state at a particular date and time, you can find the snapshot that contains the image for that particular date and time and restore the storage resource from that snapshot. It is important to note that modifications to files after the particular snapshot was created will be lost for iSCSI-based storage resources. For Shared Folder-based storage resources, a new snapshot


will be taken before the restore operation and all other snapshots, including those taken before and after the restore snapshots are still available.

Hosts connected to the storage resource continue to have access to the restored data. The snapshot schedule automatically resumes.

Shared Folders and NFS datastore snapshots

Snapshots for Shared Folder and VMware NFS datastores are performed on the entire folder or datastore; you cannot take a partial snapshot of these resources. Snapshots are based on a copy-on-first-write principle. Figure 2 illustrates the live view and snapshot view of the snapshot window if the block is modified after the checkpoint is created. The production data and snapshot data are maintained separately. It is important to note that these snapshots are read-only for Shared Folders snapshots. Data must be restored before it can be edited. However, for VMware NFS datastores, snapshots can be promoted to be read/write and editable.

Figure 2: Two views of the data during a snapshot window

End users, if they have the proper access permissions, can restore a file that was accidentally deleted by accessing the snapshots from a host that is mounted (NFS) or mapped (CIFS) to the share by adding “\.ckpt” to the end of the share path. This directs them to the hidden snapshot directory. If users are mapped to a CIFS shared folder, they have the option to access the snapshot through Microsoft Windows Explorer under the Previous Versions tab in the share’s Properties window to perform the restore. This leverages Microsoft’s Volume Shadow Copy Service (VSS) technology.

Alternatively, snapshot restores of all files within a shared folder can also be performed within Unisphere to retrieve data recorded on a specific date and time (see


Figure 3). With this approach, note that the complete snapshot is restored, bringing the whole file system back to a given point in time.

Figure 3: Restore a file from a previous snapshot of a Shared Folder

When you schedule snapshot creation of a shared folder, if the protection storage for that shared folder runs out of space, the oldest snapshot is inactivated and deleted to make space for any new snapshots.

iSCSI snapshots

Replication Manager is used to create or schedule application-consistent snapshots for iSCSI storage resources, where the application data is halted to ensure that it remains consistent with the application. Snapshots created with Replication Manager can be viewed and deleted from Unisphere. However, protection schedules are only visible in Replication Manager.

Creating snapshots in Replication Manager involves the following: Provisioning an iSCSI storage resource (including generic iSCSI, Exchange, VMware

VMFS, or Hyper-V) and enabling protection storage, where snapshots will be stored.

Obtaining an EMC Replication Manager license.

Installing and configuring Replication Manager on a host with a network connection to the VNXe system.


Creating an application set to specify the storage resource to protect in Replication Manger.

Creating a snapshot, or scheduling snapshots, of the application set.

Viewing details about the storage resource and the snapshots in Unisphere.

Data on an iSCSI snapshot is accessible only if that snapshot is promoted. Promoting and demoting of an iSCSI snapshot can be performed within Unisphere.

When the allocated protection storage runs out of space, iSCSI snapshots do not recycle themselves as exhibited with NAS snapshots. In the case of thin-provisioned storage, the space containing the iSCSI storage and snapshots will auto-extend until there is no space left in the pool. You can modify the maximum space allowed for an iSCSI virtual disk’s snapshot. The VNXe system will not create any new snapshots until this space is freed, and an alert will appear notifying you of this issue. All snapshot-related operations are executed at the application instance level. For example, in the case that there are multiple virtual disks under particular generic iSCSI storage, the snapshot creation works on all of them. You cannot selectively take snapshots of the storage.

You must keep in mind that once a snapshot is used to restore data, all snapshots that were taken after that particular snapshot are destroyed and cannot be recovered in iSCSI storage resources. This is a different behavior from the Shared Folders and VMware NFS datastores, where all snapshots remain on the system.

Protection Storage You can create protection storage when you use the Unisphere provisioning wizards to create storage resources, or you can create protection storage after you create storage. As shown in Figure 4, you can choose to do the following:

Not configure protection storage.

Configure protection storage without configuring a snapshot schedule.

Configure protection storage and create a snapshot schedule .

When you create protection storage, it is automatically provisioned to store snapshots, and to restore or recover primary storage. Protection storage is separate from the primary storage that is used for storing host, user, or application data. If protection storage is reserved for a particular storage resource, the VNXe system automatically allocates a minimum amount of protection storage to support manual snapshots of the primary data.


Figure 4: Configuring protection storage with a snapshot schedule

The protection storage for a resource can be increased without affecting its primary storage. For iSCSI storage resources, VMFS datastores, and Hyper-V datastores, you can set different host access permissions for primary storage and protection storage. You can also auto-adjust the size of protection storage, depending on the size of primary storage. When enabled, VNXe adjusts the protection storage size proportionately to any change to the size of the primary storage. For standard provisioned storage resources, it is important to note that you cannot reduce the size of protection storage once it has been created.

When provisioning Shared Folder or VMware NFS Datastore storage resources, the minimum size of the reserved protection storage is dependent on the primary storage size. The algorithm for protection size is as follows:

If the primary storage size is less than or equal to 20 GB, the minimum protection size allocated is equal to the primary storage size.

If the primary storage size is greater than 20 GB, the minimum protection size allocated is 5 percent of the primary storage size or 20 GB (whichever size is greater).

For example, if you specify 15 GB for the primary storage, the VNXe system allocates a minimum of 15 GB of reserved protection storage, resulting in an allocation of 30 GB for the storage resource. If you specify 450 GB for the primary storage, the VNXe system allocates a minimum of 22.5 GB of reserved protection storage, resulting in an allocation of 472.5 GB for the storage resource.

With auto-adjust selected, if the primary storage size increases from 500 GB to 750 GB, and there is reserved protection storage of 5 percent, then the total amount of storage allocated for the resource increases automatically from 525 GB to 787.5 GB. In this example, the protection storage size increased from 25 GB to 37.5 GB.


When provisioning Generic iSCSI storage resources, VMFS datastores, and Hyper-V datastores, the minimum protection size is 105 percent and the recommended protection size is 135 percent of the size of the allocated storage when a protection schedule is being configured. The recommended protection size is based on the primary storage size.

When configuring standard provisioned iSCSI storage resources, the storage is fully allocated from the storage pool at the time of creation and the protection space is fully allocated from the storage pool at the time of enabling protection. The total physical capacity must be available in the storage pool in order to create a virtual disk or enable the protection space. The physical capacity required is the sum of the virtual disk and protection space, and the minimum protection space size is 105% of the primary storage. Standard provisioning of iSCSI storage resources is shown in Figure 5 below.

Figure 5: Standard Provisioning of Storage Resources

When configuring thin provisioned iSCSI storage resources, the storage is not immediately allocated from the storage pool at the time of creation and the protection space is thinly provisioned. The total physical capacity does not need to be available in the storage pool in order to create a virtual disk or enable the protection space. The logical capacity of the protection space needed will be 105% of the primary storage. The physical capacity required is determined dynamically, and is the sum of the space allocated for the virtual disk and protection space. Thin provisioning of iSCSI storage resources is shown in Figure 6 below.


Figure 6: Thin Provisioning of Storage Resources

As of release VNXe Operating Environment (OE) 2.2, the protection space of iSCSI storage resources requires a minimum of 105% of logical storage to enable protection. This iSCSI protection space minimum aligns with EMC Best Practices and allows Unisphere to report usage and subscription levels more accurately. You should use the recommended protection size because depleted protection resources can lead to data loss in the storage resource primary or protection data. Figure 7 shows the Configure Protection Storage Size wizard pane when provisioning Generic iSCSI Storage. Choosing to configure the storage resource with 10 GB of primary storage, the wizard presents to the user a minimum protection size of 10.500 GB and recommended protection size of 13.500 GB.


Figure 7: Setting the Protection storage size

Table 1 displays the amount of protection storage that is provisioned relative to the size of the primary storage. With Microsoft Exchange storage provisioning, you create protection schedules in the Replication Manager interface.


Table 1 Protection Size based on Primary storage

Application

Protection Size

No Protection

Protection Size Allow Protection

(No Snapshot Schedule)

Protection Size Allow Protection (Snapshot

Schedule Configured)

Min/Default Min Default/

Recommended Min

Default/ Recommended

Shared Folders 0% 5% 5% 5%* 35%

Generic iSCSI (w/o Thin Provisioning )

0% 105% 105% 105% 135%

Generic iSCSI (w/Thin Provisioning)

0% 105% 105% 105% 135%

VMware (VMFS w/o Thin Provisioning)

0% 105% 105% 105% 135%

VMware (VMFS w/Thin Provisioning)

0% 105% 105% 105% 135%

VMware (NFS) 0% 5% 5% 5%* 35%

Hyper-V (w/o Thin Provisioning )

0% 105% 105% 105% 135%

Hyper-V (w/Thin Provisioning)

0% 105% 105% 105% 135%

Exchange (w/o Thin Provisioning )

0% 105% 135% NA NA

Exchange (w/Thin Provisioning)

0% 105% 135% NA NA

*The minimum protection size of 5% can be overridden (to 20 GB) based on the primary storage size.


Scheduling

Snapshot protection schedules are made up of one or more rules that determine how often and at what times regular snapshot operations occur. Each snapshot rule defines a snapshot type (interval), snapshot frequency, and snapshot time, and also specifies the duration to keep the snapshot.

VNXe protection rule types include:

• Hourly (several times a day).

• Daily (every day).

• At daily intervals (every n number of days).

• On specific days of the week.

• On specific days of the month.

These rules are displayed when you configure protection storage with a snapshot schedule. The daily protection rule is shown in Figure 8.

Figure 8: Modifying the protection schedule


For each storage resource provisioned you can select one of the predefined schedules (listed in Table 2), or create one or more customized schedules.

Table 2 Predefined snapshot schedule options

Schedule Name Take Snapshots Keep Snapshots

Default Protection Once every day 2 days

More Protection Once every day 7 days

Less Protection Once every day 1 days

You can create a custom protection schedule by combining a number of rules in order to obtain short-term storage protection (hourly/daily snapshots), long-term storage protection (weekly/monthly snapshots), or both. However, the more frequently the schedule takes snapshots, the more storage resources are consumed. To limit the storage consumed by snapshots, the VNXe system enables you to create a protection reserve that allocates a specific quantity of resources for snapshot operations.

Replication The ability to quickly recover data and access from a catastrophic failure at a company site is crucial to business operations. The decreasing cost of disk storage makes the use of replication technologies more attractive for enabling real-time backup and recovery. Application images can instantly be transferred between servers and between sites. It is particularly useful for organizations that have the combination of a remote office or branch office (ROBO) network scheme implemented. Data housed at the primary site can easily be copied and accessed via replicas at another site.

Replication is a process in which storage data is duplicated locally or to a remote network device. It produces a read-only, point-in-time copy of source storage data and periodically updates the copy, keeping it consistent with the source data. In case the main storage system fails, storage replication provides an enhanced level of redundancy. This minimizes the downtime-associated costs of a system failure and simplifies the recovery process for a natural or human-caused disaster.

VNXe replication provides asynchronous replication tools for creating point-in-time copies of storage resources. This is a complete copy of the data, unlike a snapshot of the data, in which only the changes to the data are saved.

There are two types of replication:

• Local – Local replication occurs within the same VNXe system.

• Remote – Remote replication occurs between a source VNXe system and a remote VNXe, VNX, or Celerra system.

For information about replication limits for VNXe systems, refer to the Simple Support Matrix EMC VNXe Series on the EMC Online Support website (https://support.emc.com).

https://support.emc.com/


Once a storage resource is created, you can create a replication session to its peer storage resource within the local VNXe system or to a remote system. You can initiate the replication session in Unisphere using the options at the end of the storage provisioning wizard (shown in Figure 9).

Figure 9: Configure a replication session at the end of the wizard

As of release VNXe Operating Environment (OE) 2.2, you can establish replication sessions for Generic iSCSI storage resources within Unisphere.2 Once the iSCSI storage resource is created, options are presented at the end of the Generic Storage Wizard (shown in Figure 10).

Figure 10: Configure iSCSI replication session at the end of the wizard

In addition, there is the option to configure a local or remote replication session at a later time by navigating to the Details page of the storage resource (shown in Figure 11).

2 After the iSCSI replication session is created in Unisphere, you will need to discover the session and set up replication from Replication Manager.


Figure 11: Configure a replication session in the Details page

Replication enables you to automatically maintain a complete second copy of the storage resource on the local or a remote system. This copy is a complete copy of the data, unlike a snapshot of the data, in which only changes to the data are saved.

For Generic iSCSI storage replication, Unisphere ensures the mapping between source and destination VNXe systems. In certain cases, new virtual disks may have been added to the source VNXe system since setting up the replication session or the VNXe system may not have been able to set up replication sessions to all the individual virtual disks. In these cases, warning messages are displayed in Unisphere notifying users that an update is needed. The session status will change to “Update Needed,” prompting you to take action. You can update the source or destination storage resources to make them match and then update the replication session to bring it back to normal state. You also have the option to delete the replication session from the Details page of the iSCSI storage resource.

Managing replication sessions

You can manage replication sessions for different storage resources in Unisphere or Replication Manager.

You can manage file-level replication entirely within the VNXe environment. VNXe supports the following types of storage resources for NAS replication:

Shared folder – Shared folder replication produces a read-only, point-in-time copy of a source production file system at a destination and periodically updates this copy, making it consistent with the source file system.

VMware NFS datastore – VMware replication supports NFS datastores. The replication session creates a point-in-time copy of VMware data and copies it to the destination. Only the data in the datastore is replicated to the destination, not the datastore itself.


For block-level (or iSCSI) replication, Replication Manager is used to create, schedule, and manage replications.

VNXe supports the following types of storage resources for iSCSI replication: Microsoft Exchange

VMware VMFS datastore

Microsoft Hyper-V

Generic iSCSI3

You can use Replication Manager to replicate data from a storage resource to the local system or a remote system. During replication, Replication Manager creates a snapshot of the storage resource.

Synchronization Frequency

In a VNXe system, for file replication, you can control the frequency at which the source and destination systems are synchronized. The value can be set between 5 and 1,440 minutes (24 hours). The default value is 60 minutes, or 1 hour as shown in Figure 12. Settings greater than 6 hours will result in a warning that recommends you to increase the Protection Reserve storage amount to a size equal to 10 percent of the application’s size. The default 5 percent reserved from protection storage (given no protection schedule was chosen) will otherwise be sufficient for settings of 6 hours or less.

Figure 12: Recovery point objective (RPO) for a replication session

You can automate the synchronization of iSCSI replication sessions by using the scheduling mechanism in Replication Manager. Replication sessions are set up as a “manual refresh.” To meet an organization’s targeted RPO, you need to schedule or manually run a job in Replication Manager.

3 Only Windows iSCSI replication is supported on the VNXe. Replication Manager does not support VNXe iSCSI with Linux. Any references to iSCSI Linux support and VNXe are limited to host attach only and not replication.


Replication Session Operations

Once a replication connection is established between the source and destination system, you can execute the following operations on the replicated data sets:

• Sync Now – This will trigger a manual sync between replication session destination and replication source. It is useful when users plan to do maintenance work or they know there will be a planned outage and want to keep the source and destination in sync.

Pause – This will stop the replication and put the session into “Paused” state. No sync between source and destination will happen while the session is paused.

Resume – This will restart the replication that has been stopped. It can be used to restart replication session that have been paused, failed over, or switched over. When used to restart a failed over or switched over replication session, the direction of the replication is reversed as well.

Failover – In a failover scenario, the production site becomes unavailable and inaccessible, typically as the result of a disaster or unexpected outage. In response, you can execute a failover from the destination system. The execution of a replication failover is not an automatic occurrence—it requires manual execution. A failover operation is asynchronous and will result in data loss if the data has not been synchronized between the source and destination prior to executing the failover. The "Sync Now" function can be used, if possible, to synchronize the production with the destination prior to executing failover to avoid losing data. This command pauses the replication and mounts the destination object as read/write so that it can act as the new source object. When the production application becomes reachable, it will be mounted as read-only. After the production site has been restored to service, the original replication session can be restarted by executing a failback on the new production application. Or the replication session can be restarted with the direction reversed using the “Resume” operation. When a failback is requested from the source system, it is treated as a “Switch Over” operation.

• Switchover – The switchover feature is typically used for disaster scenario testing or data migrations. The switchover differs from the failover in that it synchronizes the production application with the destination using the differential snapshot from the source. Switchover stops the replication session and does not restart the replication session. This option should be used if the source site is available but you want to activate the destination as read/write. This command should be executed from the source system only. This command pauses replication, mounts the source object as read-only, and mounts the destination object as read/write so that it can act as the new source object. Users can resume the replication session by either running “Resume” or “Failback” operations, depending on which direction users want to keep the replication going.

• Failback – Following a switchover or failover, you can execute a failback to restore the source as the read/write production application and to resume the replication session. Failback can only be initiated from the production side. The


failback is performed from the Replication tab on the production application. Failback resumes the replication session without losing the data written to the destination while in a failed over or switched over state. It does this by synchronizing the applications as part of the failover process. If calling a failback from a running replication session’s production side through CLI, the failback operation will reverse the replication session’s direction and resume session operation. This feature is only available through CLI.

To initiate a failover for replication, click System > System Replication in the Unisphere menu taskbar to open a list of your replication sessions, and select a replication session. Then, click the Failover button at the bottom of the screen to open a Failover dialog box.

If you initiate a failover of a local replication, the Failover dialog box shown in Figure 13 opens. You can select Sync Before Failover to start a switchover, or select the Failover Without Sync option to start a failover. However, if you initiate the local replication on the destination VNXe system, the Failover dialog box only allows you to initiate a failover operation, it does not allow you to initiate a switchover.

Figure 13: Remote failover dialog box when initiated on the source system

To initiate a failover of a remote replication, click System > System Replications in the menu taskbar to open a list of your replication sessions, and select a replication session. Then, click the Failover button at the bottom of the screen (as shown in Figure 14) to open a Failover dialog box. If you initiate a failover of a remote replication on the source VNXe system, the Failover dialog box enables you to initiate a switchover operation. If you initiate a failover of a remote replication on the destination VNXe system, the Failover dialog box enables you to initiate a failover operation.


The System Replications page (shown in Figure 14) and the Replication Details page include the Pause and Resume buttons that enable you to pause and resume a replication session. You can reverse the direction of a replication by failing over or switching over the session, and then clicking the Resume button in the System Replications page on the destination storage resource.

Figure 14: Managing Replication Sessions

For block-level replication, you must manually perform failover and failback operations using the Failover option in Replication Manager. Figure 15 displays a failover of a replication session from VNXe to VNX.


Figure 15: Failing over a replication session

Once the failover is complete, replication can be started manually, or you can wait until the next scheduled replication job runs.

The steps for the failback of a replication session are similar to the steps for the failover.

For additional information about how to configure and use Replication Manager, refer to Replicating VNXe iSCSI to VNX using Replication Manager 5.3.2 – Technical Notes on EMC Online Support website (https://support.emc.com) > VNXe Product Page.

VMware vCenter Site Recovery Manager

VMware vCenter Site Recovery Manager (SRM)4 automates the recovery process and reduces the complexity of managing and testing recovery plans. VMware vCenter SRM eliminates complex manual recovery steps and removes the risk and worry from disaster recovery.

As of release VNXe Operating Environment (OE) 2.4, the VNXe series supports integration with VMware vCenter SRM, allowing SRM to automatically drive the setup, testing, and failover portions of the disaster recovery processes for VMware NFS Datastores on VNXe series systems. SRM automatically creates and promotes snapshots of VMware NFS Datastores to snapshots that can be mounted with read-write access, also referred to as writable snapshots. Once promoted, a mount point (export path) is exposed to VMware hosts configured for the storage resource to access the snapshot through the mount point.

4 VMware documentation for SRM can be found at https://www.vmware.com/support/pubs/srm_pubs.html


https://www.vmware.com/support/pubs/srm_pubs.html


Backup and Recovery Operations The inability to recover company data after a critical failure can put an entire company at risk, with catastrophic consequences for employees, shareholders, and customers alike. In a typical data center, backups need to be performed on multiple application servers and successful backups are critical to the recoverability of data and systems enabling the business to run.

NDMP Backup

NDMP backup functionality in VNXe systems helps simplify backup and restore operations in a customer environment. VNXe systems support NDMP v2-v4 over the network; two-way NDMP backup configuration (commonly referred to as direct-attach backup) is not supported. Instead, you can configure a three-way heterogeneous backup where the tape drives are connected to a media server, also referred to as a Data Management Application (DMA) server, and the VNXe system communicates with this media server over the network (see Figure 16).

The following outlines the workflow of this NDMP design:

1. On the VNXe, enable NDMP and set a password for the NDMP account. The NDMP account credentials on the backup solution server and VNXe system must match.

2. The backup administrator requests data to be backed up.

3. The request is sent to the storage processor.

4. From the storage processor’s configuration, the VNXe system forwards data for backup to a DMA server.

5. The data is fed through a non-production network between the storage processor and DMA server.

From there, the data is sent from the DMA server to a tape device to get written onto tape.


Figure 16: Three-way heterogeneous backup configuration

With this implementation, VNXe systems store the application data at a central location, where the data can be backed up, and restored if required. Consequently, other storage systems can communicate with this DMA server and utilize its resources.

The following backup and recovery products are supported by VNXe systems to achieve the tasks above:

• EMC NetWorker®

• EMC NetWorker® FastStart

• EMC Avamar 6.0

• EMC DataDomain 5.05

• CommVault Simpana

• Symantec Backup Exec

• Symantec NetBackup with NDMP

For additional information, refer to the EMC Simple Support Matrix for EMC VNXe Series on EMC Online Support website (https://support.emc.com) > VNXe Product Page.

5 EMC DataDomain 5.0 is supported in a configuration where the DataDomain device is connected to the LAN and acts as an NDMP Tape Server.



Self-Encrypting Drives When purchasing a VNXe system, you can choose a system that supports Data at Rest Encryption through Self-Encrypting Drives (SEDs). This feature provides security for stored data when physical control of the drives is lost. The Self-Encrypting Drives perform the encryption automatically and transparently at the individual drive level with no noticeable performance impact.

Encyrption is the process of transforming data to make it unreadable to anyone except those possessing specialized knowledge, referred to as the authentication key. A VNXe SED system encrypts data before it writes data to an SED drive. This protects the data on the disk against theft, hardware loss, and attempts to read the disk directly by physically deconstructing the drive using methods such as a drive recovery service. Reading encrypted data requires the authentication key to unlock the drive. Once the data is unlocked, the SED drive decrypts the encrypted data back to its original form.

For additional information, refer to the EMC Data-at-Rest Encryption for VNXe: Self-Encrypting Drives White Paper on EMC Online Support website (https://support.emc.com) > VNXe Product Page.

Conclusion System and data availability is a top-most priority for customers. Outages are costly to businesses if not resolved immediately. This is particularly the case with small to medium size businesses. VNXe systems can ease these customers’ concerns and increase the availability of their storage.

VNXe systems enable you to protect data against localized failures, outages, and disasters through snapshots, replication, and backup and recovery operations. VNXe systems protect data at rest through the use of Self-Encrypting Drives (SEDs). With snapshots, end users can recover files or directories deleted from a previous point in time from their local desktops. Snapshots are easily maintained via protection schedules. You can also create a manual snapshot when appropriate, making it much easier to fulfill restore requests.

Data and application consistency via replication ensures that you will be able to recover and restart the application from the copy in the event of a service interruption. Replicating data remotely ensures disaster recovery protection for production applications. VMware vCenter Site Recovery Manager (SRM) can be utilized to automate the disaster recovery processes in VMware and VNXe environments. Further, these replicas can be repurposed for backup acceleration and restoration of data, or to simplify and automate data refreshes for testing and reporting. Implementing these measures in combination significantly decreases costs and alleviates staff resources.



Backup and recovery operations includes NDMP functionality, which offers users the flexibility to backup data using different combinations of compliant network-attached file servers, backup devices (such as tape drives), and NDMP-compliant management applications. In addition, NDMP provides centralized control of company-wide data backup management.

References The following can be found on EMC Online Support website (https://support.emc.com):

EMC VNXe Storage Systems – A Detailed Review.

EMC Unisphere for VNXe: Next-Generation Storage Management – A Detailed Review.

EMC Simple Support Matrix for EMC VNXe Series.

Replicating VNXe iSCSI to VNX using Replication Manager 5.3.2 – Technical Notes.

The following can be found on the VMware support page:

VMware vCenter Site Recovery Manager Documentation – On the VMware website, click Support & Downloads > Support Resources > Documentation > vCenter Site Recovery Manager (https://www.vmware.com/support/pubs/srm_pubs.html) .


https://www.vmware.com/support/pubs/srm_pubs.html

Documents

EMC VNXe DATA PROTECTION · VNXe Data Protection ... and folders from Linux/UNIX hosts located on a network. ... coordinates the entire data replication process from discovery and