london ceph day: ceph for smbs: are we there yet?
DESCRIPTION
Martin Loschwitz, Co-Founder, HastexoTRANSCRIPT
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
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