From: Jonathan Williams (jonathw@shubertorg.com)
Date: Thu Nov 07 2002 - 15:12:00 EST
We have a storageworks cabinet with a bunch of those 72.8GB 10K RPM Ultra3 SCSI
disks (part No. 232432-B22). We use these disks for Informix Databases. My DBA
over here just gave me this document talking about allocating disk space for the
database (nice document to read after you've been online with it for a year and
a half). He just wants to make sure the way we set up these disks was
correct...or if we've just been extremely lucky for the past 18 months with this
system. This is what the document said:
"Many computer systems and some disk-drive manufacturers keep information for a
physical disk drive on the drive itself. This information is sometimes referred
to as a valume table of contents (VTOC) or disk label. The VTOC is commonly
stored on the first track of the drive. A table of alternate sectors and
bad-sector mappings (also called a revectoring table) might also be stored on
the first track.
If you plan to allocate partitions at the start of a disk, you might need to
use offsets to prevent the databse server from overwriting critical information
required by the operating system. For the exact offset required, refer to your
disk-drive manuals"
Well that would be nice, but I don't have any manuals for the disk drives, and
couldn't seem to locate much info at all about these drives through various
google searches (but I did see some places with some pretty good prices).
Anyway...I was just wondering if these disks, or if the operating system (Tru64
5.1, and 5.1a) requires an offset so that you don't overwrite the disk labels.
The disks are in a storageworks cabinet with HSG80 controllers that go to a
16-port fibre switch, which goes to the system. The disks are hardware mirrored
through the controllers. Operating system wise, the disks are sliced up with
LSM. No offsets were used on the first volume, so the data does begin at the
beginning of the disks.
I don't think I'm overwriting the disk labels on these drives, I'm sure I would
have noticed pretty quickly .
But can anyone give me some more info on this? Should I be worried?
Jonathan Williams
Unix Systems Administrator
The Shubert Organization, Inc.
This archive was generated by hypermail 2.1.7 : Sat Apr 12 2008 - 10:48:58 EDT