[1732] in linux-scsi channel archive
enabling error recovery
daemon@ATHENA.MIT.EDU (Jim Van Zandt)
Sun Apr 20 22:09:09 1997
To: linux-scsi@vger.rutgers.edu
Date: Sun, 20 Apr 1997 20:44:50 -0400
From: Jim Van Zandt <jrv@vanzandt.mv.com>
I just installed a new 4.33 GB IBM disk. The scsiinfo report starts
like this:
Vendor: IBM
Product: DCAS-34330 !#
Revision level: S60BB3A2099373H8014
Serial Number 'B3A20993 '
Data from Rigid Disk Drive Geometry Page
----------------------------------------
Number of cylinders 8205
Number of heads 6
Back in January, Gerard Roudier <groudier@club-internet.fr> wrote:
>Set ARRE to 1 as suggested by Stefan.
Then Michael Weller <eowmob@exp-math.uni-essen.de> wrote:
>Use scsiinfo to check also if there are any alternate sectors
>[reserved] for automatic relocation (look on the formatting mode pages).
I find that error recovery is already enabled:
Data from Error Recovery Page
-----------------------------
AWRE 1
ARRE 1
However, there seem to be no spare sectors or tracks:
Data from Format Device Page
----------------------------
Removable Medium 0
Supports Hard Sectoring 1
Supports Soft Sectoring 0
Addresses assigned by surface 0
Tracks per Zone 49230
Alternate sectors per zone 0
Alternate tracks per zone 0
Alternate tracks per lun 0
Sectors per track 171
Bytes per sector 512
I calculate that there are 8205*6=49230 tracks in all, so there must
be only one zone.
How much of the disk should I set aside? My other scsi disk has one
alternate sector for every 765. That would suggest about 64 alternate
tracks for this disk, or 64*171=10944 alternate sectors.
Should I set "alternate tracks per zone", or "alternate sectors per
zone", or both? What are the advantages and limitations of alternate
tracks vs. alternate sectors?
Suppose I set "alternate tracks per zone" to 64. Then I have my scsi
host adapter (a BusLogic 948) do a low level format, right?
This disk already has a lot of defects:
Data from Defect Lists
----------------------
889 entries in manufacturer table.
Cyl Head Byte_offset
54 4 52224
54 4 52736
...
I assume that those sectors have already been reassigned.
If I do a low-level format, will they still be reassigned?
- Jim Van Zandt
