topic Re: fbackup in Operating System - HP-UX

fbackup

A.G.M. Velthof — Wed, 30 Jul 2003 09:02:56 GMT

I want to make the backup over the network and use:
fbackup -i /files -f -|remsh machinename dd ibs=64k obs=32k of=/dev/rmt/1m.
So far it works fine.
When I want to recover some files, I use:
remsh machinename dd ibs=32k obs=64k if=dev/rmt/1m|/usr/sbin/frecover -xv -i /files -f -
Some file are recovered correct but some of them gave an error:
"file trailer does not match file header" and also "block checksum mismatch"
Anyone any idea?

Re: fbackup

Darren Prior — Wed, 30 Jul 2003 09:19:05 GMT

Hi,

The more usual method of using fbackup with a remote tape drive is:

fbackup -i /files -f machinename:/dev/rmt/1m

Is there a special reason why you are using remsh and dd?

regards,

Darren.

Re: fbackup

melvyn burnard — Wed, 30 Jul 2003 09:19:51 GMT

are both systems HP-UX? If so, why not just use fbackup to hte remote system?
i.e.
fbackup -i /files -f remotenode:/dev/rmt/1m after putting in a .rhosts entry in the remote host

Re: fbackup

RAJESH GANGADHARAN — Wed, 30 Jul 2003 09:45:42 GMT

Hi
Insted of using remsh and dd you can directly use the remote tape drive. eg:
fbackup -f remotehost:/devicefile.

-Rajesh

Re: fbackup

A.G.M. Velthof — Wed, 30 Jul 2003 09:59:27 GMT

The reason why I piped the fbackup to dd is the speed.
I always used fbackup -i /files -f machinename:/dev/rmt/1m but the total backup time increased to 20 hours.
With the help of dd the total time is 7 hours.

Re: fbackup

melvyn burnard — Wed, 30 Jul 2003 10:06:31 GMT

Have you looked at tuning hte fbackup config file?
This may help in reducing hte time. I would look at the blocksperrecord, records,readerprocesses to start with.
You would probably want to do the changes on both systems to se e if it does help

Re: fbackup

A.G.M. Velthof — Wed, 30 Jul 2003 10:32:57 GMT

No I did not do that.
I will play a little with the configfile and let you know what the result will be.

Alfons

Re: fbackup

Bill Hassell — Wed, 30 Jul 2003 12:09:16 GMT

No matter whether you use a local or remote tape drive, a config file is imperatrive since the defaults for fbackup are badly out of date. This file is suitable for DDS, DLT and Ultrium tape drives:

blocksperrecord 256
records 32
checkpointfreq 1024
readerprocesses 6
maxretries 5
retrylimit 5000000
maxvoluses 200
filesperfsm 2000

Note that when you use a remote tape drive (whether using dd or fbackup's built-in remote tape capability), you lose searchmarks, the ability to place highspeed searchmarks onto the tape. Fast searchmarks will allow restoration of a specific file or directory within a few minutes rather than a serial read through the tape. For effective network backups at very high speeds and reliability, you should look at commercial products such as HiComp's HiBack product, or HP's OpenView Data Protector (aka, Omniback). These products handle network backups, support tape changers, can push data to parallel tape drives, recover from media errors, etc.