File corruption by OS problem

File corruption by OS problem

Post by Matt Barr » Fri, 11 Oct 1996 04:00:00



I'm running FreeBSD 2.1.0 on a P90, 32mb RAM, with an Adaptec 2940
running the following SCSI peripherials:
ID 0 - Seagate ST32550N
ID 1 - Conner CFP2105S
ID 2 - Seagate ST15230N
ID 4 - 9-track SCSI tape drive

The ID 1 and ID 2 hard drives are new. The system has been up for
about a year with only the first (ID 0) hard drive and the SCSI tape
drive.

I disklabelled/fdisked/newfs'ed  the new hard drives by hand. I
created a single partition/slice on each drive (/dev/sd[12]a). The
whole installation procedure went fine (once I figured out how to do
it).

After I came back up, I move some of my database onto the new drives.
The system ran for a while, then I started getting complaints from my
database software. It turned out the database files were corrupt.

I then wrote a simple program to test the drives. The program just
opened a file and wrote sequential bytes (0x00, 0x01, 0x02, and so on)
until the disk was full. It then closed the file, reopened it, and
started reading and verifying the data. This program reported that the
data was corrupt - what it wrote was not always what it read. The
corruption started about 16mb into the file and was widespread after
that. My program reported that the corrupt bytes usually (but not
always) contained 0xff instead of what it expected. The corruption was
usually in a pair of (e.g. two consecutive) bytes.

Either I have a weird hardware problem, or I configured the disks
improperly when I fdisk/disklabel/newfs'ed them, or FreeBSD has a bug.
The first may be true - does anyone else have as many SCSI peripherals
as I do on a single bus? The second may be true, but I can't figure
out anything I did wrong. I hope the third is not true, but am
beginning to wonder.

Anyone have any thoughts?

 
 
 

File corruption by OS problem

Post by Steven G. Karg » Fri, 11 Oct 1996 04:00:00



> I'm running FreeBSD 2.1.0 on a P90, 32mb RAM, with an Adaptec 2940
> running the following SCSI peripherials:
> ID 0 - Seagate ST32550N
> ID 1 - Conner CFP2105S
> ID 2 - Seagate ST15230N
> ID 4 - 9-track SCSI tape drive

[deleted]

Quote:> Anyone have any thoughts?

(1)  Check your termination of your SCSI bus.

(2)  Check that you have a good cable

(3)  Did you rebuild a kernel with support for sd1 and sd2?

(4)  What does fsck report for these drives?

(5)  How did you mount the partitions of these drives?

--
Steve


http://troutmask.apl.washington.edu/~kargl/sgk.html

 
 
 

File corruption by OS problem

Post by Matt Barr » Fri, 11 Oct 1996 04:00:00


On Thu, 10 Oct 1996 09:51:24 -0700, "Steven G. Kargl"


>(3)  Did you rebuild a kernel with support for sd1 and sd2?

Huh? Didn't have to, /dev/*sd[12]* were already present and I was able
to access the drives from the beginning.

Quote:>(4)  What does fsck report for these drives?

Dunno; I'll check that. Bet fsck finds some problems, since I'm
convinced I have random data corruption.

Quote:>(5)  How did you mount the partitions of these drives?

mount /dev/sd1a /u1
mount /dev/sd2a /u2
 
 
 

File corruption by OS problem

Post by Mike McGaugh » Sat, 12 Oct 1996 04:00:00




>> I'm running FreeBSD 2.1.0 on a P90, 32mb RAM, with an Adaptec 2940
>> running the following SCSI peripherials:
>> ID 0 - Seagate ST32550N
>> ID 1 - Conner CFP2105S
>> ID 2 - Seagate ST15230N
>> ID 4 - 9-track SCSI tape drive
>[deleted]

>> Anyone have any thoughts?
>(1)  Check your termination of your SCSI bus.
>(2-5) Some other good suggestions.

I had a similar problem at one stage; it turned out that my PCI bus
speed settings (which were not causing any obvious problems for DOS and
OS/2) were a little optimistic for FreeBSD.  If you haven't done so
already, set them more conservatively and see what happens.

Cheers,

    Mike.

 
 
 

1. mysterious file corruption, OS or hardware?

I'm getting some weird file corruptions on a SCO 3.4.2 system on a no-name
m486 machine. The corruption only occurs when a file is read from tape or
moved to a new location. The tape is fine as a second read results in a
correct file. However after gunzipping them I may end up with a corrupt file.
The sizes remain the same. There seems to be no pattern in which files get
corrupted or not. No hardware errors are reported by SCO, except for 1 SCSI
error on block 0 when the system boots up.

Any clues? Is this software or hardware related, or both? The corruption has
been causing the machine to crash (again with no error messages) and causing
further corruption. The client is looking at totally replacing the hardware
which is over 3 years old.

Thanks for any pointers,
Zeyd
--
---

NCURSES is available from ftp.netcom.com:pub/zm/zmbenhal/ncurses
Current version is 1.9.4

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