HMC_QUS-& HACMP

7/28/2019 HMC_QUS-& HACMP

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Here are some questions on HMC and some of the technologies related toit.

1. Whats the maximum # of Servers and Partitions HMC can support ?

HMC can support up to 32 servers with a total of 254 logical partitions

2. IS it requried to configure HMC as DHCP? Justify your answer.

3. How do we connect P4 and P5 servers to a HMC?

POWER5 HMCs cannot manage POWER4 servers, and vice versa

4. Can we use the same HMC to manage P4, P5 and P5+ servers ?

Existing POWER4 HMCs can be upgraded to support POWER5 servers This involves a

complete overwrite of the disk and the loss of all previous configuration information,including user profiles

If you want to recreate partition profiles from an HMC being upgraded, capture theprofiles using the Command Line Interface or screen captures

The profiles will have to be re-entered manually on the newly installed POWER5 HMC

5. When we power on a HMC for the first time, which username andpassword we use for logon ?

When the HMC is powered on the first time, login as hscrootand use abc123, the

default password

6. What for we use the Recovery CD that comes with the HMC ?

New HMCs come preinstalled

The Recovery CD that comes with the HMC is used to reinstall, such as following a disk

failure

When used with a current Critical Console Date backup, it will restore profiles, userids,passwords, etc., after a disk is lost or corrupted

7. Can we manage a server without an HMC ? Plz explain.

Managing a serverwithout an HMC

Server can run in Manufacturing Default Mode, with all resources but no logical partitioning,CoD or Service Focal Point, or

8. Why we use private connection for HMC ?

Private network connects only the HMC and the servers it manages

Private network replaces the serial connection on POWER4 servers


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Dual HMCs require two unique private networks

9. If a HMC is not able to ping/reach/resovle hsotname the LPARs? Whats the consequence ?

10. What are the default IP Address of the service processors?

Default service processor connections:

Eth0 HMC1 255.255.255.0 192.168.2.147

Eth1 HMC2 255.255.255.0 192.168.3.147

11. How many service processors are there in a P5 Server ?

2 service processors

12. How will you connect a HMC to a 9118-575 and 9119-590 servers?

Through ether net cable for 9119-590

Through serial cable for 9118-575

13. How you login to the ASMI? What username and password (for the first time) you use?

Use a laptop attached to one of the two service processor Ethernet ports and access theASMl

User name :admin

p/w: admin

14. Can we set static IP for the 9119-590/595 servers' FlexibleService Processors (FSP) ? Justify your answer.

15. After connecting a P5 server to a HMC, what are the default userid's available and which userid will be created ?

Default user ids are admin and general

16. What are the name of the those ports available in P5 servers whichare used to connect to a HMC ?

Port name is front side BPA0 (J01)and back side BPA1(J01)

17. What is the difference between desktop model and rackmount HMC model ?

18. What are the 2 ways to connect to a HMC ?

1 . Websm

2. Telnet (or) SSH


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19. How will you shutdown/reboot a HMC ?

When I logoff it will ask me to shutdown / reboot.

20. Can we use IVM running in a P5 server to manage LPARs in another P5 server ?

21. How do we connect a I/O drawers to P5 CEC ?

22. Expand the abbreviations ...

HMCLPARDLPARMPARBPDBPCBPFBPEBPA

BPRFSPDCAUEPOPU Book

AMDMDAMSAVPDOSCDCACECDDR

RIOLIC

23. How do we update firmware in P4 and P5 servers ?

24. What are the different levels of firmware in P4/P5 servers ?

25. What daemons are required for a successfull DLPAR operation ?

26. In which file, RMC daemon stores the node id ?

27. How will you find the HMC name/IP from login to a LPAR ?

28. Do HMC need a /etc/hosts. If not, how do the hmc gets the TCPIP details of each LPAR ?

29. When does the ASMI on web browser available ?

30. How to find the good memory in a LPAR? "lsattr -El mem0" might report wrong if a DLPARoperation failed.


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Guys as usual I have collected some questions on HACMP.

1. What are the different kind of failures HACMP will answer(respond) ?

2. List some of Cluster Topology objects?

3. List some of Cluster Resources ?

4. Do HACMP detect VG mirror failures ? If not how to make it(VG) redundant or how tofindout/sort out the mirror failures?

5. List the steps required to configure a cluster ?

6. List out some of the HACMP log files ?

7. What are the 3 policies related to resource group configuration ?

8. Expand the following :

a) HACMPb) RGc) C-SPOCd) SPOFe) ODMf) SRCg) RSCT

9. How to list the info on heartbeat data ?

10. How to list out the info on cluster manager and DNP Information ?

11. What is the HA daemon that gets started by /etc/inittab ?

12. How will you start cluster services in a node? Give the command as well as smitty fastpath.

13. How many network adapters are required/recommended in a node belonging to a cluster ?

14. For a 2 node cluster (with 1 RG) with 2 N/W adapters for each node, how many IP Label/Address are required. Give some example ?

15. How can we achieve non-ip network (for hearbeat) ?

16. What are the different ways to set up achieve IP Address Takeover ?

17. Is a non-ip network requried for a cluster? Say Yes/No. Also justify your answer

18. How many service IP addresses we can have for a single resoruce group ?


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19. What is the difference between communication interface adn communication device? Also listtheir usage.

20. Persistent IP Label/Address is a floating IP Label. True/False. Justify your answer

21. Which of the following IP Label is stored in AIX ODM.

a) Service IPb) Boot IPc) Stand-by IPd) Persistent IP

22. If we use a (LUN)disk for a heartbeat, what type of VG it should belong? Normal, Big,Scalable, Enhanced Concurrent Mode Vg ?

23. While stopping cluster services, what are the different type ofshutdown modes available? Do justify.

24. How will you view the cluster status ?

25. How to list out the RG Status?

26. What are the ways to eliminate Single Points of Failure ?

27. What is the max. # of nodes we can configure in a single cluster ?

28. What is the max. # of resoruce groups we can configure in a single cluster ?

29. What is the max. # of IP address can be known to a single cluster ?

30. Which of the following disk technologies are supported by HACMP ?

a) SSA

b) SCSI

c) FC

31. Which command lists the cluster topology ?

32. Which command sync's the cluster ?

33. What is the latest version of HACMP and what versions of AIX it supports ?

1. What are the different kind of failures HACMP will answer(respond) ?

ANS:a) Node Failureb) Network Failurec) Network Adapter Failure

For other failures like disk, application we have to configureseperately using LVM, application monitoring scripts, etc..

Be clear that HACMP is just fault resilience and not fault tolerant


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like mainframes. They cant go for mainframe becoz of its high cost.Thats the reason people are going for ha clsuters.

2. List some of Cluster Topology objects?

ANS:

a) Nodeb) Network (IP and Non-IP)c) Network Adapterd) Physical Volumes

3. List some of Cluster Resources ?

ANS:a) Application Serverb) Volume Groupsc) Logical Volumesd) File Systemse) Service IP Label/Addressesf) Tape resourcesg) Communication Links

4. Do HACMP detect VG mirror failures ? If not how to make it(VG)redundant or how to findout/sort out the mirror failures?

ANS: HACMP dont detect VG failures. This has to be implemented usingAIX LVM Soft Mirroring or else in SAN side.

5. List the steps required to configure a cluster ?

ANS:

a) Plan AIX, HACMP levels, Cluster configuration, network diagram,etc..

b) Install AIX, fixes

c) Configure AIX- Storage (Adapters, VG, LV, File Ssytems)- Network (IP Interfaces, /etc/hosts, non-IP networks and devices)- Application Start and stop scripts

d) Install HACMP file sets and fixes in all the cluster nodes. Thenreboot all the ndoes in the clusters

e) Configure HACMP Environment- Topology (Cluster, node names, HACMP IP and non-ip networks)- Resources (Application Server, Service Label, VG, File System, NFS)- Resource Groups (Identify name, nodes, policies)

f) Synchronize and test the cluster

g) Tune the system and HACMP based on test result- syncd frequency


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- Basic VMM Tuning- Failure detection rate- I/O Pacing

h) Start HACMP Services

6. List out some of the HACMP log files ?

ANS:a) /usr/es/adm/cluster.log - Messages from scripts and daemons (DateTime Node Subsystem PID Message)b) /tmp/hacmp.out - Output from configuration, start and stop eventscriptsc) /usr/es/sbin/cluster/history/cluster.mmddyyd) /tmp/clrmgr.debug - Cluster manager activitye) /tmp/clappmon..log - Application monitor logsf) /var/ha/log/top*,/var/ha/log/grpsvcs* - RSCT Logsg) /var/hacmp/clcomd/clcomd.log - communications daemon logh) /var/hacmp/clverify - Previous successful and unsuccessfulverification attemptsi) /var/hacmp/log/cl_testtool.log - Cluster test tool logs

7. What are the 3 policies related to a resource group ?

ANS:a) Start up - Online On Home Node Only, Online On First AvailableNode, Online Using Node Distribution Policy, Online On All AvailableNodes.

b) Fallover - Fallover To Next Priority Node In The List, FalloverUsing Dynamic Node Priority, Bring Offline (On Error Node Only).

c) Fall back - Fallback To Higher Priority Node In The List, Never

Fallback

8. Expand the following :

ANS:a) HACMP - High Availability Cluster Multi Proccessingb) RG - Resource Groupc) C-SPOC - Central Single Point of Contactd) SPOF - Single Point of Failuree) ODM - Object Data Managerf) SRC - System Resource Controller

g) RSCT - Reliable Scalable Cluster Technology

9. How to list the info on heartbeat data ?

ANS:# lssrc -ls topsvcs

10. How to list out the info on cluster manager and DNP Information ?


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ANS: # lssrc -ls clstrmgrES

11. What is the HA daemon that gets started by /etc/inittab ?

ANS: clcomd gets started by init process. It has an entry in /etc/inittab

12. How will you start cluster services in a node? Give the command aswell as smitty fastpath.

ANS:To Start Cluster Services:Command: #/usr/es/sbin/cluster/etc/rc.cluster (Check the optionsavailable for tis command)Smitty Fast Path: clstart

To Stop Cluster Services:Command: /usr/es/sbin/cluster/utilities/clstopSmitty Fast Path: clstop

13. How many network adapters are required/recommended in a nodebelonging to a cluster ?

ANS:Minimum 2 network adapters are required per node. This is required tomanage network adapter failure event.

14. For a 2 node cluster (with 1 RG) with 2 N/W adapters for eachnode, how many IP Label /Address are required. Give some example ?

ANS:Lets consider a very much used cluster configuration.

Cluster cluster_DB with 2 nodes nodea and nodeb.Nodea have 2 network adapters with nodea_boot ip label and nodea_stdbyip label on en0 and en1 resepctively.And Nodeb have 2 network adapters with nodeb_bootip and nodeb_stdbyipon en0 and en1 resepctively.This cluster have a VG, Service IP grouped in a resource group.Minimum 1 service IP is required for a RG.

When we start RG in nodea, ndoea_bootip on en0 will bet replaced/aliased by the service ip.

15. How can we achieve non-ip network (for hearbeat) ?

ANS:Non-IP Network can be achieved thru any of the following waysa) Serial/rs232 Connection (using /dev/ttyx devices) - Widely used inold clustersb) Disk based heart beat (over an ECM(VG) disk) - Widely used inrecent clusters. Becoz People want to eliminate those lengthy serialcables.


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c) Target Mode SCSI - Not widely usedd) Target Mode SSA - Not widely used

16. What are the different ways to set up achieve IP AddressTakeover ?

ANS:a) IP Address Takeover via IP Aliasb) IP Address Takeover via IP Replacement

17. Is a non-ip network requried for a cluster? Say Yes/No. Alsojustify your answer

ANS: Yes. To avoid split-brain problem.

18. How many service IP addresses we can have for a single resorucegroup ?

ANS: Not sure. Have to check in smitty screen.

19. What is the difference between communication interface andcommunication device? Also list their usage.

ANS: Dont know how to explain. Below line should answer:/dev/en0 is a communication interface whereas /dev/tty1 is acommunication device./edv/en0 is used for IP Network and /dev/tty1 is used for non-ipnetwork. I mean tty1 is used only for heardtbeat.

20. Persistent IP Label/Address is a floating IP Label. True/False.Justify your answer

ANS: No. It resides on a single ndoe and dont move to another node.

21. Which of the following IP Label is stored in AIX ODM.

a) Service IPb) Boot IPc) Stand-by IPd) Persistent IP

Ans: Only Boot IP and Stand-by IP are stored in AIX ODM.

22. If we use a SAN disk for a heartbeat, what type of VG it shouldbelong? Normal, Big, Scalable, Enhanced Concurrent Mode Vg ?

ANS: ECM (Enhanced Concurrent Mode) Volume Group


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23. While stopping cluster services, what are the different type ofshutdown modes available? Do justify.

ANS:a) gracefulb) graceful with takeoverc) forced

24. How will you view the cluster status ?

ANS: #/usr/es/sbin/cluster/clstat

25. How to list out the RG Status?

ANS: #/usr/es/sbin/cluster/sbin/utilities/clRGinfo

26. What are the ways to eliminate Single Points of Failure ?

ANS:a) Node : Using multiple nodesb) Power Source : Using multiple circuits or uninterruptible powersuppliesc) Network Adapters : Using redundant network adaptersd) Network : Using multiple networks to connect nodese) TCP/IP Subsystem : Using non-IP networks to connect adjoining nodesand clientsf) Disk Adapter : Using redundant disk adapter or multipath hardwareg) Disk : Using multiple disks with mirroring or raidh) Application : Add node for takeover; configure application monitori) Administrator : Add backup or very detailed operationsguidej) Site : Add additional site

Dont assume that HACMP will eliminate all SPOF. We have to plan toeliminate all kindaa SPOF including UPS and AC for the Data Center.

27. What is the max. # of nodes we can configure in a single cluster ?

ANS: Max. we can have 32 nodes in a cluster

28. What is the max. # of resoruce groups we can configure in a singlecluster ?

ANS: Max. we can have 64 resource groups in a cluster

29. What is the max. # of IP address can be known to a singlecluster ?

ANS: Max. 265 IP addresses/labels can be known to a cluster

30. Which of the following disk technologies are supported by HACMP ?


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ANS:a) SCSIb) SSAc) SAN

31. Which command list the cluster topology ?

ANS: /usr/es/sbin/cluster/utilities/cltopinfoIts a widely used command by HACMP admin to view the cluster topologyconfiguration

32. Which command sync's the cluster ?

ANS: #cldare -rtV normal

33. What is the latest version of HACMP and what versions of AIX itsupports ?

ANS: HACMP 5.4 is the latest version of HACMP. This version supportsonly from AIX 5.2

34. How to test the disk hearbeat in a cluster ?

ANS:To test the disk heartbeat link on nodes A and B, where hdisk1 is theheartbeat path:

On Node A, #dhb_read -p hdisk1 -rOn Node B, #dhb_read -p hdisk1 -t

If the link is active, you see this message on both nodes:

Link operating normally.

35. List the daemons running for HA cluster.

ANS:clcomd - STarted during boot thru /etc/inittabclstrmgrES - Started during clstartclsmuxpdES - Started during clstart. This daemon is not availablefrom HACMP 5.3; SNMP server functions are included in clstrmgrESitself.clinfoES - Started during clstart

36. What is the command used to move RG online ?

ANS: cldare and clRGmove

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HMC_QUS-& HACMP