IDS on AIX 5.2 Offsets? lv types?

[malcolm weallans]

We are running IDS 9.3 on AIX 5.2. We have discovered
that on AIX 5.2 the logical volume control block gets
corrupted if offset 0 is used. This doesn't normally
cause problems until the volume group is exported and
imported.

We also have a problem with defining logical volume
type. Some installers are setting up the system with
the lv type set to jfs whilst others are setting it to
raw.

I would welcome any advice on the correct settings for
offset and lv type, and more importantly any advice on
what I should do to migrate the system to the correct
settings.

regards

Malcolm
sending to informix-list

[Murray Wood (IList)]

Malcolm

We have exactly the same issue on AIX. You must use an offset of 8Kb (I think) for every logical volume on AIX 5. Its only an issue if you need the AIX control info - which is required if you have a disk failure and need to re-mirror the logical volume.

Similarly at the front of the disk on Solaris, you cannot use the first disk block (normally 4Kb) as it contains the disk partition table. Either create the logical volume from block 1 or use a 4Kb offset.

MW

sending to informix-list

[Hal Maner]

"malcolm weallans" <malcol...@btopenworld.com> wrote in message
news:ceb5t2$a9j$1...@news.xmission.com...

We use a 40K offset on AIX (which corresponds to 10 pages for IDS) which,
so far, has proven to be a sufficiently high and therefore "safe" number.
Since we have many many GB of disk space nowadays, we will gladly waste a
few KB in return for no nasty potential data override problems. We also
always set the lv type to raw. We always had good results with the above
guidelines so we keep reusing them...

Regards,

Hal Maner
M Systems International, Inc.
www.msystemsintl.com