Problem on DAT ?

[Pierre POMES]

Hi jason,

Thanks for your answer. 

> then use the no rewind tape device to start dumping the second filesystem which
> will overwrite above.

Yes I totally agree, it was a typing error. I use the rewinding device
to rewind, but after that I use the non rewinding for all filesystems. 

> i don't understand why you are following the above sequence of commands - am
> i missing something.

In fact, my filesystems are not listed en /etc/fstab. That's why I use
the device name rather than the mount point. When I run the backup
process on particular device, this device is not mounted. 

But do you think it would be better to define the filesystem in
/etc/fstab (with the noauto option, since I don't want to mount the
filesystem at startup), and use the mount point in my dump command
rather than the device name ?


> other things to check.  what sort of dat drive is it ?  you have not specified
> the size of your first filesystem.  also check that you have the appropriate tapes.

My drive is a DDS4, and I use DDS4 tapes. So I can backup 20GB without
compression. The total size of my filesystems is smaller than 20GB. 

One question about compression : I would like to use compression (latter
the total may exceed 20GB), but there is no device /dev/zst0 or
/dev/nzst0 as I expected...(I was used to use ftape and devices
/dev/qft0 and /dev/zqt0 some years ago). 

I tried to use the "-z" option with dump, but according to the man page,
this option can work only if the drive can write variable length blocks.
I assumed my drive cannot write such blocks, since I obtained only a
write error at the beginning of the backup :

[rootusr at gemenos ~]# dump -z -0uf /dev/st0 /dev/sdb6
  DUMP: Date of this level 0 dump: Fri Jun  7 10:31:56 2002
  DUMP: Dumping /dev/sdb6 (an unlisted file system) to /dev/st0
  DUMP: Added inode 8 to exclude list (journal inode)
  DUMP: Added inode 7 to exclude list (resize inode)
  DUMP: Label: none
  DUMP: Compressing output at compression level 2 (zlib)
  DUMP: mapping (Pass I) [regular files]
  DUMP: mapping (Pass II) [directories]
  DUMP: estimated 6895473 tape blocks.
  DUMP: Volume 1 started with block 1 at: Fri Jun  7 10:32:12 2002
  DUMP: write error 30 blocks into volume 1: Invalid argument

dmesg output is "st0: Write not multiple of tape block size". Is there
another way ot use compression ?

Now back to my original problem... This morning I cleanned my tape once
again. I tried the backup again, but always the same error :

[rootusr at gemenos ~]# mt -f /dev/st0 rewind  -> ok
[rootusr at gemenos ~]# dump -0f /dev/nst0 /dev/sdb5 -> ok (0,06MB, always
ok, very small filesystem)
[rootusr at gemenos ~]# dump -0f /dev/nst0 /dev/sdb6
  DUMP: Date of this level 0 dump: Fri Jun  7 10:33:46 2002
  DUMP: Dumping /dev/sdb6 (an unlisted file system) to /dev/nst0
  DUMP: Added inode 8 to exclude list (journal inode)
  DUMP: Added inode 7 to exclude list (resize inode)
  DUMP: Label: none
  DUMP: mapping (Pass I) [regular files]
  DUMP: mapping (Pass II) [directories]
  DUMP: estimated 6895473 tape blocks.
  DUMP: Volume 1 started with block 1 at: Fri Jun  7 10:34:05 2002
  DUMP: dumping (Pass III) [directories]
  DUMP: dumping (Pass IV) [regular files]
  DUMP: 10.28% done at 2363 kB/s, finished in 0:43
  DUMP: 28.31% done at 3254 kB/s, finished in 0:25
  DUMP: 47.12% done at 3610 kB/s, finished in 0:16
  DUMP: write error 4104290 blocks into volume 1: Input/output error
  DUMP: Do you want to rewrite this volume?: ("yes" or "no") 

Here is the dmesg output :

st0: Error with sense data: Deferred st09:00: sense key Hardware Error
st0: Error with sense data: Current st09:00: sense key Hardware Error
st0: Error on write filemark.

This error can happen at any moment, sometimes just after 10%, here in
my exemple after 47%... I'am afraid my drive is out of order.... :-(

-- 
Pierre POMES                        mailto:ppomes at reservit.com
Interface Technologies