Topic: Tape backup doesn't work

[Nikolai Ensslen]

Hi there,

I just replaced the NT servers of my company with the SME 6.0 beta 3.

The tape backup option I configured to backup daily doesn't work but delivers the following failure log:

|------------------------------------------------------------
| Doing level 0 backup of set all using tar
| All sets = full (1 tapes)
| Rewinding & erasing tape...
| Creating index key 200309250200
| Backup set full (/ /boot)
| Tape #0
|------------------------------------------------------------
At block 0.
|------------------------------------------------------------
| File number 1, tape index 200309250200
| Backup of: /
| Date of this level 0 backup: Thu Sep 25 02:03:15 2003
| Date of last level 0 backup: the epoch
|------------------------------------------------------------
| cd "/" && find . -depth -xdev ! -type s ! -regex "news/articles" ! -regex
|   ".*~"$ -print0 | tar --create --null --files-from=-
|   --ignore-failed-read --same-permissions --no-recursion --totals --label
|   "level 0 / Thu Sep 25 02:03:15 2003 tar+gzip from ensslen-dc1" --sparse
|   --atime-preserve -b 20 --file - | gzip -4 | buffer -m 3m -s 10k -u 100
|   -t -p 75 -B -o "/dev/nst0"
|------------------------------------------------------------
buffer (writer): write of data failed: Input/output error
bytes to write=10240, bytes written=-1, total written         10K
ERROR from backup, exiting
offending command(s):
cd "/" && find . -depth -xdev ! -type s ! -regex "news/articles" ! -regex ".*~"$ -print0 | tar --create --null --files-from=- --ignore-failed-read --same-permissions --no-recursion --totals --label "level 0 / Thu Sep 25 02:03:15 2003 tar+gzip from ensslen-dc1" --sparse --atime-preserve -b 20 --file - | gzip -4 | buffer -m 3m -s 10k -u 100 -t -p 75 -B -o "/dev/nst0"
 
--------------------------------------------------------------------------------------------

The server runs on an IBM Netfinity 5600 with a Sony DDS4 tape drive.

Can anyone get out something more out of this log than me? - I just guess that the tape has to be re-formatted from it's former system (ARCserve).

But does that mean that I have to re-format each tape the server places it's backup on daily?

And how to format a tape with an e-smith server?


Thank you for any ideas!


Nick

[marco]

make sure that you are not trying to back-up more data than what the tape can store uncompressed.  I use a stt22000 tape drive with 10/20 gig tapes....can only do backups that are less then 10 gig....haven't been able to configure with compression to get 20 gig stored.  Have looked into it, but no real answer why.

hope this helps

marco

[Nikolai Ensslen]

Yes, right, that could be.

I've got a 20/40 DDS4 system and the storage on my server has around 25 to carry by the moment.

Could you please post your error message of flexbackup so that I can be sure yours is also my problem?


Thank you.


Nick

[Graeme Fleming]

.. the compression is hardware based on the Sony DDS4 drives (Seagate too) so its just a jumper setting (or dip switch) on the physical drive - dunno about Travan drives as I don't use them.

HTH

[Kelvin]

Hi,

It was my understanding that the "gzip -4" parameter specified by the backup config means the server will attempt to compress the files (except file types listed in the $nocompress_types parameter) hence giving you software based compression, irregardless of your tape drive's hardware compression capabilities (or lack thereof). Or am I mistaken ?

Kelvin

[marco]

Kelvin,
Those were my thoughts also, but I changed the settings from 4 to 9, from 4 to 1, etc.... with no luck.  I also tried different types of back-ups...changed from dump to everything else.  I can only make the back-up work with dump and less then 10GB of data on a 10/20 GB tape.  Remember, all I did to fix the back-up problem was remove an I-Bay that I used for network storage.  There was about 15GB of  info total on the server.  I deleted about 6 GB of data files and the back-up started working.   Go figure....

Here is the ending error message from the log file:

buffer (writer): write of data failed: Input/output error
bytes to write=10240, bytes written=-1, total written    9339690K
|------------------------------------------------
| Backup start: Fri Jun 27 14:13:36 2003
| Backup end:   Fri Jun 27 20:48:46 2003
|------------------------------------------------
At block 18679441.
|------------------------------------------------
| File number 2, index key 200306271413.28
| Backup of: /boot
| Date of this level 0 backup: Fri Jun 27 20:48:56 2003
| Date of last level 0 backup: the epoch
|------------------------------------------------
| (touch -d "Thu Jan 01 00:00:00 1970" /tmp/refdate.1472 ; cd /boot ; find . \
|  -xdev ! -type d -newer /tmp/refdate.1472 -print | sed -e "s%^./%%" | egrep \
|  -v "news/articles" | egrep -v ".*~"$ | tar --create --files-from=- \
|  --same-permissions --same-order --no-recursion --totals --label "level \
|  /boot Fri Jun 27 20:48:56 2003 tar+gzip from ws1" --atime-preserve \
|  --verbose --sparse -b 20 --file - | gzip -9 ; rm -f /tmp/refdate.1472) | \
|  buffer -m 3m -s 10k -u 100 -t -p 75 -B -o /dev/nst0
|------------------------------------------------
level 0 /boot Fri Jun 27 20:48:56 2003 tar+gzip from ws1
boot.b
chain.b
message
message.ja
os2_d.b
e-smith.pcx
mitel.pcx
System.map-2.2.19-7.0.8
module-info-2.2.19-7.0.8
vmlinux-2.2.19-7.0.8
vmlinuz-2.2.19-7.0.8
vmlinuz
System.map
module-info
initrd-2.2.19-7.0.8.img
kernel.h
boot.0300
map.0305
boot.0340
map.0345
Total bytes written: 2979840 (2.8MB, 1.4MB/s)
buffer (writer): write of data failed: Input/output error
bytes to write=10240, bytes written=-1, total written          0K
|------------------------------------------------
| Backup start: Fri Jun 27 20:48:56 2003
| Backup end:   Fri Jun 27 20:48:58 2003
|------------------------------------------------
At block 18679441.
|------------------------------------------------
| Rewinding...
|------------------------------------------------

[Kelvin]

Hi Marco,

What type of files are your trying to backup ? Are they compressible and if so, do you expect them to be partially compressible, moderately compressible or highly compressible ?

Usually, when a backup software reports it has written xxx number of bytes to tape, that's the amount that is physically transferred to and stored on the tape, not necessarily the amount that's backed up.

Say for example you have 12 GB of data that's a mix of moderately compressible and highly compressible files, and by running those files through a gzip process you end up with 8GB of compressed data, some tape backup software will report that is has written 8GB of data to the tape and not 12GB of data, you just need to know for your particular software (sorry, given up on flexbackup so I don't know for sure).

If your data is mostly picture files and mp3 music (which won't be compressed) or other files that don't compress much, then, you will only get at most 10GB (perhaps slightly more) of storage and not 20GB.

Unfortunately, flexbackup does not support multi tape spans (the newer flexbackup might, I don't know). Perhaps give the arkeia contrib a try. At least when the first tape fills up, it is ejected and you can then insert a second tape and ask arkeia to continue through the server manager, and not just abort the entire backup.

Kelvin