[OpenIndiana-discuss] Migrating root zpool from old disks to new one. only one system available

[Jim Klimov]

2012-06-12 15:40, J. V. пишет:
> On 12/06/12 09:16 AM, Rich wrote:
>> Won't zpool replace fail b/c the new disks require ashift=12 and his
>> existing pool devices have ashift=9?
>
> This should work fine:
>
> HP Microserver, upgrading a mirrored pool from 2TB HDs to 3TB HDs. At one
> point, the pool had one 2TB HD with 512 sectors and the other with 4k
> sectors (both in a mirror). Seems there was a bit of a performance hit, but
> everything worked fine.
>
> When I upgraded from 2TB to 3TB, the 3TB HDs were both 4k sectors:

Did the 3TB disk also report to the OS that it uses 4k sectors?
What ashift value is used by the pool, ultimately? Example:
# zdb -l /dev/rdsk/c2t0d0s0 | grep ashift
         ashift: 9
         ashift: 9
         ashift: 9
         ashift: 9

If your 4KB disks use ashift=9 it is possible to get problems
worse than decreased performance ;)

Note that the ashift is set on a top-level vdev (the second-tier
component of a pool) and the value is saved into/read from its
vdevs (edge-tier components), and a pool can mix top-level vdevs
with different ashifts, i.e. if it is a raid10 type of setup.

PS: Do you use an HP N40L? Did you test if more than 8Gb RAM
can fit into it (using DDR3 ECC sticks larger than 4Gb), or
does the server's BIOS forbid that?

HTH,
//Jim Klimov