Re: else or Debian (Re: ZFS performance (was: Re: deduplicating file systems: VDO with Debian?))
Am 11.11.2022 um 07:36 schrieb hw:
> That's on https://docs.freebsd.org/en/books/handbook/zfs/
>
> I don't remember where I read about 8, could have been some documentation about
> FreeNAS.
Well, OTOH there do exist some considerations, which may have lead to
that number sticking somewhere, but i have seen people with MUCH larger
pools.
In order to avoid wasting too much space, there was a "formula" to
calculate optimum pool size:
First take an amount of disks that is a result of 2^^n (like
2/4/8/16/...) and then add the number of disks you need for redundancy
(raidz = 1, raidz2 = 2, raidz3 = 3). That would give nice spots like 4+2
= 6 (identical) disks for raidz2, or 11 for raidz3. Those numbers are
sweet spots for the size of vdevs, otherwise, more space gets waisted on
the drives. But that is only ONE consideration. My motherboard has 8
connectors for SATA, + 2 for NVME, which limited my options more than
anything.
And after long considerations, i opted for 4 mirrored vdevs, giving even
more space to redundancy, but gaining read speed.
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