[OpenIndiana-discuss] zpool on the second partition of an external disk

[Udo Grabowski (IMK)]

On 09/09/2017 15:45, PÁSZTOR György wrote:
> Hi,
>
> "Udo Grabowski (IMK)" <udo.grabowski at kit.edu> írta 2017-09-09 13:12-kor:
>> No, s2 has been actively configured to be used as a zpool slice,
>
> Yepp. That is the normal behaviour.

No, it's not. The normal behaviour is using either s0 or the
whole disk (which, again, is setup as s0 internally). ZFS tools
never activate s2 because its the backup partition.

>
>> zfs tools don't do that. Therefore, the next one that will touch
>
> I think, You are wrong. ZFS does that. At least according to docs.

Read that doc you cited below again. s0 is the rpool in that doc,
not s2. s2 is never used for anything except addressing the whole
partition.

>
>> slice s8 will destroy the data on "slice" s2 (the problem is just
>
> Ho doesn't actively use s8. It's default behaviour again.
>

And that's the problem. Always expect the unexpected. Some day some
tool or idiot will touch that, and your nice s2 pool is gone. Use the
things as they are intended to be used, not just in any way you like
because it happens to "work". Administrators should use good practice,
not hacks.

>> the other way round than you think). Therefore, by convention don't
>> use s2 actively, any other activity on s<n> (<n>/=2) will destroy
>> data.
>
> If you read the docs, his scenario perfectly fits to the layout what the
> docs says:
> https://wiki.openindiana.org/oi/Advanced+-+Creating+aligned+rpool+partitions
>
> The only difference here, that he uses p1 for the "other" os, and uses p2
> for the pool. But besides that, it's a textbook example: s8 is created as
> "boot slice". boot slice is one cylinder long. No useful data there, and he
> didn't intend to use s8 directly. He just wants to use the zpool.
>
(see above)

best regards,
-- 
Dr.Udo Grabowski    Inst.f.Meteorology a.Climate Research IMK-ASF-SAT
http://www.imk-asf.kit.edu/english/sat.php
KIT - Karlsruhe Institute of Technology            http://www.kit.edu
Postfach 3640,76021 Karlsruhe,Germany  T:(+49)721 608-26026 F:-926026