Topic: Very slow tape backup

[stian]

Could be a hardware problem? Im using a Dell PII 400Mhz with 256Mb ram. An Adaptec SCSI card and an exabyte VXA-2 tape station. The backup performs very slow... Anyone know of a solution?

flexbackup version 1.1.7 (http://flexbackup.sourceforge.net)
/etc/flexbackup.conf syntax OK

|------------------------------------------------------------
| Checking 'buffer' on this machine... Ok  Checking /bin/sh on this
|machine... bash2
|------------------------------------------------------------
| Doing level 0 backup of set all using tar  All sets = full (1 tapes)  
|Rewinding & erasing tape...
| Creating index key 200504091500
| Backup set full (/ /boot)
| Tape #0
|------------------------------------------------------------
At block 2.
|------------------------------------------------------------
| File number 1, tape index 200504091500  Backup of: /  Date of this
|level 0 backup: Sat Apr 09 15:00:14 2005  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 / Sat Apr 09 15:00:14 2005 tar+gzip from smeserver"
--sparse |   --atime-preserve -b 20 --file - | gzip -4 | buffer -m 3m -s
10k -u 100 |   -t -p 75 -B -o "/dev/nst0"
|------------------------------------------------------------
Total bytes written: 21321297920 (20GB, 513kB/s) Kilobytes Out 20175650
|------------------------------------------------------------
| Backup start: Sat Apr 09 15:00:14 2005
| Backup end:   Sun Apr 10 02:16:28 2005
|------------------------------------------------------------
At block 2017568.
|------------------------------------------------------------
| File number 2, tape index 200504091500  Backup of: /boot  Date of this
|level 0 backup: Sun Apr 10 02:16:38 2005  Date of last level 0 backup:
|the epoch
|------------------------------------------------------------
| cd "/boot" && 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 /boot Sun Apr 10 02:16:38 2005 tar+gzip from
smeserver" |   --sparse --atime-preserve -b 20 --file - | gzip -4 | buffer
-m 3m -s |   10k -u 100 -t -p 75 -B -o "/dev/nst0"
|------------------------------------------------------------
Total bytes written: 10373120 (9.9MB, 1.3MB/s) Kilobytes Out 5600
|------------------------------------------------------------
| Backup start: Sun Apr 10 02:16:38 2005
| Backup end:   Sun Apr 10 02:16:52 2005
|------------------------------------------------------------
At block 2018129.
|------------------------------------------------------------
| Rewinding...
| Removing old level 0 log of all (dated 200504082200)  Compressing log
|(all.0.200504091500.gz)  Linking all.latest.gz -> all.0.200504091500.gz
|------------------------------------------------------------

File  Contents    (tape index 200504091500)
---------------------------------------------
0    <tape index key>
1    level 0 / Sat Apr 09 15:00:14 2005 tar+gzip from smeserver
2    level 0 /boot Sun Apr 10 02:16:38 2005 tar+gzip from smeserver

[irian]

Did you configure the SCSI Controller Bios.
At boot press CTRL+A

[stian]

Im not really sure what to configure there.... Could you help me with some suggestions?

[irian]

There is a setting about enableing bigger than 2Gb capacity drives.
This used to cause some problems.
With a Compaq machine I had to disable the SCSI-Bios else the machine wouldn't even boot.
There is documentation on the Adaptec website.

[simona2110]

1) You need to establish if the tape drive is the cause of the slow backup or if it is something with your system configuration.

2) Download the VXAtool from www.exabyte.com and run the short test, it should complete in less than 4mins. This verifies that the back-end of your system is working correctly e.g. scsi card, tape drive and tape are all okay.

3) If the test fails or takes longer than expected please upgrade firmware, clean the drive and retest with a new tapes.

4) I suspect that your system is causing the problem, backup software writes logfiles during a backup operation thus if the backup software is installed on the same physical disck that you are backing up then you can experience very slow backups, virus software can also cause slow backups.

I also use a VXA-2 drive for backups and I easily get >400MB/min on a P4 system with twin hard drives.

kind Regards
Simon

[stian]

The Tool-software did run succesfully. I wrote 1Gb to the tape in few minutes! Then it must be something with the backupsoftware... Does annyone have any suggestions?

[KelvinLee]

Does annyone have any suggestions?

Yes. Forget about flexbackup. Try Arkeia or Tapeware instead.

You'll be thankful you did when you have to do a quick restore of just one file (or a bunch of files).

The built in server manager interface to flexbackup cannot do selective restores (the add ins help but still a far cry from being end-user friendly).

Arkeia also has a strange-ish approach to backup software (as testified by many, many clients) but at least it has a GUI that's fairly navigateable. Tapeware is still the easier but is commercial software.

Kelvin

[stian]

What package of Arkeia should I use for the SmeServer 6.5RC1 distro?

[jackl]

Stian
A selective restore can be done from flexbackup if you set it to use dump
/sbin/e-smith/config setprop flexbackup Type dump
/sbin/e-smith/expand-template /etc/flexbackup.conf
 
There is a howto by Darell May on recovering files using flexbackup somewhere on the contribs site. Or else type flexbackup --help

SME started to use tar in favour of dump at version 6, I think because a bad block on a dump tape means all data on the tape is lost, this apparently is not as big a problem using tar. However flexbackup only supports an interactive restore if dump is used.

What I have noticed with backups is the type of data is crucial, compressed files such jpg mpegs etc take much longer as the backup tries to compress them again. You might have noticed the backup of the boot partition was at 1.3MB/sec almost 3 times faster than your data partition

I have a fully licensed version of tapeware but I prefer to use flexbackup as it is easy to use if you take the time to study it. Also the ability to transfer from an old to a new system by restoring a single tape is one of the simplest disaster recovery systems I have seen, not only can you restore your data but also you configuration and settings in one simple operation.
While using tapeware for a while I can't recall noticing any increase in performance, flexbackup I believe can be tweaked to suit various different tape drives, by changing parameters controlling block size etc. Please try to get to know flexbackup before you write it off.

Regards
Jack