Hi,
We are considering redesigning our storage pools because of problems
we've had and to simplify our environment. Here's our current
environment (server is AIX 4.1.4 ADSM 2.5.1.12):
SSA #1 SSA #2
LVL1 LVL2
DISK01 DISK02
FILE01 FILE02
TAPE01 TAPE02
The 2 DISK01/02 pools are DEVTYPE=DISK (they are for files <5 MB).
The FILE01/02 pools are DEVTYPE=FILE (they are for files >5 MB).
This was originally set up with 2 objectives:
1. If an SSA adapter was lost, maintain access to 1/2 disks. We have
since
found out that all the disks are cabled through both adapters and
if we lose
1 adapter, all our disk is still available. Therefore, 'splitting'
our pools down
the middle for availability purposes is not an issue.
2. The file pools are supposed to be better performing for large files
(simulates
streaming, i.e. writing to a tape drive). However, since we have
only 2
drives, our DISK01/DISK02 pools migrate to the FILE01/FILE02 pools
when
they reach a threshold (FILE01/FILE02) migrate to TAPE01/TAPE02.
Therefore it seems like we are potentially moving files a lot
(first to write
the small ones into the DISK pools, a second time to move these
small
files to the FILE pools, and finally a third time to tape when the
FILE
pools reach threshold).
Also, we've experienced problems where a node points to a disk pool
(such as
disk02 pool) for backup and runs out of space so the backup fails, yet
there is plenty of space on the other pools (i.e. disk01). It's also a
manual balancing act for us to figure out when we add a new node which
'side' to put it on.
So, I've convinced myself we want to switch to one pool. But, I'm
curious on others out there.. Does anyone else run 'split' pools like
we do, or file pools? And if so, what has been your experience? Has
anyone ever attempted to combine a split environment into a single
storage pool, like we are going to?
Many thanks.
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