Ceph for SMBs Are we there yet?

Martin Gerhard Loschwitz

© 2013 hastexo Professional Services GmbH. All rights reserved.

Who?

SMBs? Why even bother?

What is an SMB?

Number of employees & revenue per year

Do these work for IT?

Cloud & Automation: Do more work

with less people

Revenue: May be low, but high when compared to the actual work effort

Long story short: Typical SMB definitions don’t work well for IT

Also, IT is different from most

other businesses

Storage is a perfect example for this!

Ceph is interesting for both SMB providers and

SMB customers

Which features make Ceph interesting for SMBs?

Commodity Hardware

No Vendor Lock-In

Scale-Out

Open Source

Low price per Megabyte

40TB, 3 replicas = € 21.000

Typical situation: SMBs migrating

away from SANs

Typical SMB use cases for storage

Virtualization storage

KVM/Qemu: Yay

VMWare, HyperV: Ouch

Backup storage

MO

N

MO

N

MO

N

Users

Objects

OS

D

OS

D

OS

D

OS

D

OS

D

OS

D

OS

D

OS

D

OS

D

OS

D

OS

D

OS

D

OS

D

OS

D

Ceph Block Device Block-level interface

driver for Ceph

Ceph Object Gateway

ReSTful API to access Ceph

CephFS POSIX file system access to Ceph

MO

N

MO

N

MO

N

Users

Objects

OS

D

OS

D

OS

D

OS

D

OS

D

OS

D

OS

D

OS

D

OS

D

OS

D

OS

D

OS

D

OS

D

OS

D

Ceph Block Device Block-level interface

driver for Ceph

Ceph Object Gateway

ReSTful API to access Ceph

CephFS POSIX file system access to Ceph

But no specific backup features

CDN-like storage

MO

N

MO

N

MO

N

Users

Objects

OS

D

OS

D

OS

D

OS

D

OS

D

OS

D

OS

D

OS

D

OS

D

OS

D

OS

D

OS

D

OS

D

OS

D

Ceph Block Device Block-level interface

driver for Ceph

Ceph Object Gateway

ReSTful API to access Ceph

CephFS POSIX file system access to Ceph

May require application porting

Cloud Computing

Challenges

File storage

CIFS / NFS: Meh

The Gateway problem

iSCSI

Looks good, eh? Well, it isn’t.

Involves iSCSI on top of RBD

Results in loopback RBD mappings

RBD mappings are kernel processes

Kernel processes may not move into Swap

Now imagine this …

Ceph needs memory, flushes cache

Flushes stuff that belongs to the RBD mapping

RBD tries to flush stuff by writing back to Ceph

Deadlock (under heavy load)

iSCSI

iSCSI

HDD efficiency

3 2U-Server 22 HDDs 4TB each 2 Replicas

“Don’t do that”

8 HDDs 4TB each 2 Replicas

9 2U-servers

OSDs need RAM & CPU

Replication efficiency

Multi-DC installations

Summary

goo.gl/S1sYZ (me on Google+)

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