booting off a ZFS pool consisting of multiple striped mirror vdevs

[Dan Naumov]

On Fri, Feb 19, 2010 at 1:03 AM, Matt Reimer <mattjreimer at gmail.com> wrote:
> On Thu, Feb 18, 2010 at 10:57 AM, Matt Reimer <mattjreimer at gmail.com> wrote:
>>
>> On Tue, Feb 16, 2010 at 12:38 AM, Dan Naumov <dan.naumov at gmail.com> wrote:
>>>
>>> > I don't know, but I plan to test that scenario in a few days.
>>> >
>>> > Matt
>>>
>>> Please share the results when you're done, I am really curious :)
>>
>> Booting from a stripe of two raidz vdevs works:
>> FreeBSD/i386 boot
>> Default: doom:/boot/zfsloader
>> boot: status
>> pool: doom
>> config:
>>                     NAME      STATE
>>                     doom     ONLINE
>>                   raidz1     ONLINE
>>             label/doom-0     ONLINE
>>             label/doom-1     ONLINE
>>             label/doom-2     ONLINE
>>                   raidz1     ONLINE
>>             label/doom-3     ONLINE
>>             label/doom-4     ONLINE
>>             label/doom-5     ONLINE
>> I'd guess a stripe of mirrors would work fine too. If I get a chance I'll
>> test that combo.
>
> A stripe of three-way mirrors works:
> FreeBSD/i386 boot
> Default: mithril:/boot/zfsloader
> boot: status
> pool: mithril
> config:
>                     NAME      STATE
>                  mithril     ONLINE
>                   mirror     ONLINE
>             label/mithril-0     ONLINE
>             label/mithril-1     ONLINE
>             label/mithril-2     ONLINE
>                   mirror     ONLINE
>             label/mithril-3     ONLINE
>             label/mithril-4     ONLINE
>             label/mithril-5     ONLINE
> Matt

A stripe of 3-way mirrors, whoa. Out of curiosity, what is the system
used for? I am not doubting that there exist some uses/workloads for a
system that uses 6 disks with 2 disks worth of usable space, but
that's a bit of an unusual configuration. What are your system/disc
specs and what kind of performance are you seeing from the pool?

- Sincerely,
Dan Naumov