Strange ZFS warning: mirror contains devices of different sizes.

[Dave]

I've just fitted a Belkin USB 2.0 USB card in a Blade 2000 running
Solaris 10 update 5. (At least I was expecting it to be USB 2, but now I
find Solaris is going to use it only as USB 1 - see my other post for
more on this.)

Anyway, forgetting the speed issues for the moment, I attached a pair of
Western Digitial "My Book Essential Edition" 1 TB external USB disks.
The disks were both bought from Amazon within a week of each other, and
for all intents are purposes look the same.

I can create a ZFS pool for each disk individually, and they are the
same size (as expected), since the disks are as far as I am aware identical.

# zpool create tmp1 c6t0d0
# zpool create tmp2 c7t0d0
# zpool list
NAME SIZE USED AVAIL CAP HEALTH ALTROOT
tmp1 928G 88K 928G 0% ONLINE -
tmp2 928G 88K 928G 0% ONLINE -

df shows two file systems of the same size.

Filesystem kbytes used avail capacity Mounted on
<snip>
tmp1 957874176 24 957874091 1% /tmp1
tmp2 957874176 24 957874091 1% /tmp2

Now I destroy the pools.

# zpool destroy -f tmp1
# zpool destroy -f tmp2

Finally I try to mirror them.

# zpool create TBmirror mirror c6t0d0 c7t0d0
invalid vdev specification
use '-f' to override the following errors:
mirror contains devices of different sizes

Now I can create the mirror if I use the -f option

# zpool create -f TBmirror mirror c6t0d0 c7t0d0
# zpool list
NAME SIZE USED AVAIL CAP HEALTH ALTROOT
TBmirror 928G 89K 928G 0% ONLINE -

Again, using df I see the mirror is the exact same size as the
individual disks were.

# df -k
Filesystem kbytes used avail capacity Mounted on
/dev/dsk/c1t1d0s0 20168929 15875917 4091323 80% /
<snip>
TBmirror 957874176 24 957874090 1% /TBmirror

Any ideas why a warning/error is generated by zpool for two apparently
identical external USB disks?

[usenetper...@gmail.com]

On May 9, 2:23 pm, Dave <f...@coo.com> wrote:
> I've just fitted a Belkin USB 2.0 USB card in a Blade 2000 running
> Solaris 10 update 5. (At least I was expecting it to be USB 2, but now I
> find Solaris is going to use it only as USB 1 - see my other post for
> more on this.)
>
> Anyway, forgetting the speed issues for the moment, I attached a pair of
> Western Digitial "My Book Essential Edition" 1 TB external USB disks.
> The disks were both bought from Amazon within a week of each other, and
> for all intents are purposes look the same.

Look

prtvtoc might reveal they ARENT identical...?

[Dave]

Since posting I have made some changes to allow USB 2.0 to work. The
result of that is the device files have changed. But prtconf on the new
device files shows the disks the same

# prtvtoc /dev/rdsk/c8t0d0
* /dev/rdsk/c8t0d0 partition map
*
* Dimensions:
* 512 bytes/sector
* 1953525168 sectors
* 1953525101 accessible sectors
*
* Flags:
* 1: unmountable
* 10: read-only
*
* First Sector Last
* Partition Tag Flags Sector Count Sector Mount Directory
0 4 00 34 1953508717 1953508750
8 11 00 1953508751 16384 1953525134
# prtvtoc /dev/rdsk/c5t0d0
* /dev/rdsk/c5t0d0 partition map
*
* Dimensions:
* 512 bytes/sector
* 1953525168 sectors
* 1953525101 accessible sectors
*
* Flags:
* 1: unmountable
* 10: read-only
*
* First Sector Last
* Partition Tag Flags Sector Count Sector Mount Directory
0 4 00 34 1953508717 1953508750
8 11 00 1953508751 16384 1953525134

[usenetper...@gmail.com]

On May 9, 2:54 pm, Dave <f...@coo.com> wrote:

> 0 4 00 34 1953508717 1953508750

> 8 11 00 1953508751 16384 1953525134
> # prtvtoc /dev/rdsk/c5t0d0

> 0 4 00 34 1953508717 1953508750
> 8 11 00 1953508751 16384 1953525134

They WERE of different sizes...? : >
They appear to be OK now. I doubt the labels were identical is all.