Using ZFS Functionality
BonFire supports arrays of
both hard disks as well as SSDs. SSDs are generally
managed by WildFire-Storage's Enterprise Storage Stack.
This allows you to use low-cost SSDs and achieve maximum
performance.
Arrays of hard disks are
suported with ZFS and ZVols. ZFS is good at mass
storage where performance is not a big factor.
Bonfire will auto-detect
hard disks and allow you to configure them for ZFS using
either mirrored or RAID-z pools. This configuration is
available from the BonFire web interface and is very easy to
use. The BonFire web interface does not allow you to
configure SSDs for use with ZFS. If you choose to do
so, you can manually configure ZFS and then allow BonFire to
provision ZVols after a ZFS ZPool is created. If you
choose to manually configure ZFS for use with SSDs, please
consider the following issues:
Enterprise SSDs:
ZFS requires enterprise SSDs. ESS can effectively
use read-intensive and consumer SSDs. ZFS cannot.
Mirrored vs RAID
/z Sets: ZFS performs best with mirrored
drives. RAID /z sets are much slower with ZFS.
Caching SSDs and
ZIL Logs: Are fully usable with ZFS, but
again, they must be built with Enterprise SSDs. In
particular, ZIL log devices need to be built with "high
endurance" devices.
Performance
Comparison with ESS: ZFS with mirrored
enterprise SSDs is typically about
1/3rd the speed on read and 1/10th the speed of writes as
the same array with ESS. The ESS array will also wear
drives much slower.
If you do choose to build
an array with ZFS and SSDs, they will be fully functional,
just not as fast as the same hardware with ESS. Wtih
ZFS be sure to pick your SSDs carefully.
ZFS, and in particular
large storage servers, need a lot of RAM and a lot of processing
power: much more than that required by ESS. You
should use powerful dual socket servers with ZFS. It
is especially important to only use ECC RAM with ZFS.
ZFS storage is licensed in
BonFire based on the available "user storage". This
calculation is the same regardless of HDD vs SSD or the
presence of ZIL log or Cache devices.
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