We have  a linux server that is using 2 CX4-960.

One storage pool has been created on one CX4 and a second storage pool with the same size created on 2nd CX4

Then 1 thin lun has been created in a 1st storage pool and a 2nd thin lun with same size 430GB in a 2nd storage pool

Theses 2 luns are accessed by one server Linux RedHat 6.2 or 6.3

These are the same size LUN accessed through mirroring (writing Y) Linux RedHat 6.2 or 6.3.

On the server, theses 2 luns are mirrorred with the following commands :

pvcreate /dev/mapper/mpathbh /dev/mapper/mpathbg

vgcreate vg450_13200 /dev/mapper/mpathbh /dev/mapper/mpathbg

lvcreate -L5G -m1 -nlibimap13200 vg450_13200 --mirrorlog core /sbin/mke2fs -j /dev/vg450_13200 libimap13200 -L libimap13200 5G /var/lib/imap

Finally, we note that when a 5GB filesystem is created ,we have 5GB used in the 1st thin lun on the main storage,and 430GB on the other storage.

No data so far been copied to the FileSystem.

To summarize on the main CX , we have only 5Gigas allocated on a 1st CX and 430GB taken automatically in the 2nd thin lun.

NB:The main storage imply that the 1st thin lun is created on this storage

At the opposite , if the 1st thin is created on the 2nd array , the problem is identical but reversed.

Is it a normal behaviour ? Linux problem ? Array problem ?

Thank you

In attached documentation , 4 spcollect for 2 storages