Monday, October 4, 2010

Solaris 11 Express 2010.11 and ZFS

Besides ZFS data set encryption the upcoming Solaris Express release (Which seems to be tagged 2010.11) will contain several enhancements to ZFS besides dataset encryption that was mentioned earlier:
  • RAID-Z/mirror hybrid allocator
  • "Normally mirror vdevs contain mirrored data, RAID-Z vdevs contain RAID-Z data, etc. However, for latency-sensitive metadata, we can use a mirrored layout across the children of a RAID-Z vdev. This ensures that such metadata can be read in a single I/O."

  • Support for decompression, checksumming and raidz in zdb -R will make it much easier to debug ZFS errors on disk or just to learn more about the on-disk format of ZFS.

  • Performance improvements for listing ZFS filesystems.

The downside of this is that these are features only present in Oracles internal gate and not other distribution besides Solaris 11/Express and the S7000/FishWork appliances can use them until and if Oracle releases the source after Solaris 11 is released.

I hope the Solaris 11 Express license will allow me to use Solaris 11 for my private storage needs, S7000 are nice and deployed at work but still a bit too expensive for my datacenter at home ;)

6977913 RAID-Z/mirror hybrid allocator
6757444 want zdb -R to support decompression, checksumming and raid-z


Alex said...

i dont conceptually understand the "RAID-Z/mirror hybrid allocator" feature. any chance you could elaborate ?

Henkis said...

Raid-z writes block across all devices in the set which requires all (or N-1) IOPS to read the block back. By placing metadata in a mirrored layout in a raidz pool it can be read with just a single IOPS. Otherwise raidz is limited IOPS limited to that of a single device (but sequential read can of course be faster)