Hello!
I currently have 4 SAS disks arranged in two pairs (two RAID-0 arrays):
Code:
<localhost.localdomain>.../user>lsscsi
[1:0:0:0] cd/dvd ASUS DRW-24D5MT 1.00 /dev/sr0
[6:0:0:0] disk ICP KA_RAID_0 V1.0 /dev/sda
[6:0:1:0] disk ICP KA_RAID_1 V1.0 /dev/sdb
[6:1:0:0] disk FUJITSU MAU3147RC 0104 -
[6:1:1:0] disk FUJITSU MBA3147RC HPF1 -
[6:1:2:0] disk TOSHIBA MK2001TRKB 0105 -
[6:1:3:0] disk TOSHIBA MK2001TRKB 0105 -
[9:0:3:0] tape HP Ultrium 1-SCSI N2CG /dev/st0
The two FUJITSU MAU3147RC disks comprize the KA_RAID_0 (on which
the OS is installed and also my home directory) and the two TOSHIBA MK2001TRKB disks
comprize the KA_RAID_1 array with large data of images/videos.
Lately the TOSHIBA MK2001TRKB disks started developing bad sectors so I bought
a new pair of 2 TB SAS disks.
All disks are connected to the Adaptec ICP5165BR RAID controller.
The first two disks (KA_RAID_0) are connected to the port 0 of the controller,
channels 0 and 1 (via 1-to-4 cable), the second two disks (KA_RAID_1)
are connected to the channels 2 and 3 of the same port 0.
I'll soon get a new pair of 2 TB SAS disks and at first will connect
then to port 1, channels 0,1 of the controller.
If everything works OK I expect the new RAID-0 array to be /dev/sdc,
to format it and to copy on it the contents of the /dev/sdb.
Now to the question part: what'll happen if after the copying I'll swap the connections of
the disks so that the two new disks will be connected to port 0, channels 2,3
of the controller (where old KA_RAID_1 array disks were connected)
and the old disks which were connected to port 0, channels 2,3 will now be connected
to port 1, channels 0,1?
Will this ruin both arrays or new disk will become /dev/sdb, the old will become /dev/sdc
and the data remain intact? In other words, does the memory of the controller about
how the arrays are organized is "per port/channel" and it forgets everything once the
connection is changed or it's "per disk" and the controller scans the disk parameters
at each boot and reconstructs the arrays from that info?
If the controller won't be able to continue recognizing the arrays after the swap
and I'll revert the connections to be like it was before the swap, will the arrays
be recognized and working "as in the past" or just any change in disks connection
will wipe out anything the controller remembers, thus wiping the data? I have a backup tape
and did two full backups and can make a third backup but I would like to have some
advance knowledge of what to expect of such an experiment?
TIA,
kaza.
