[lustre-discuss] zfs -- mds/mdt -- ssd model / type recommendation

[Stearman, Marc]

We are using the HGST S842 line of 2.5" SSDs.  We have them configures as a raid10 setup in ZFS.  We started with SAS drives and found them to be too slow, and were bottlenecked on the drives, so we upgraded to SSDs.  The nice thing with ZFS is that it's not just a two device mirror.  You can do an n-way mirror, so we added the SSDs to each of the vdevs with the SAS drives, let them resilver online, and then removed the SAS drives.  Users did not have to experience any downtime.

We have about 100PB of Lustre spread over 10 file systems.  All of them are using SSDs.  We have a couple using OCZ SSDs, but I'm not a fan of their RMA policies.  That has changed since they were bought by Toshiba, but I still prefer the HGST drives.

We configure them as 10 mirror pairs (20 drives total), spread across two JBODs so we can lose an entire JBOD and still have the pool up.

-Marc

----
D. Marc Stearman
Lustre Operations Lead
stearman2 at llnl.gov
925.423.9670




On May 4, 2015, at 11:18 AM, Kevin Abbey <kevin.abbey at rutgers.edu> wrote:

> Hi,
> 
> For a single node OSS I'm planning to use a combined MGS/MDS.  Can anyone recommend an enterprise ssd designed for this workload?  I'd like to create a raid10  with 4x ssd using zfs as the backing fs.
> 
> Are there any published/documented systems using zfs in raid 10 using ssd?
> 
> Thanks,
> Kevin
> 
> 
> -- 
> Kevin Abbey
> Systems Administrator
> Rutgers University
> 
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