Help on fbackup

[so.nimda]

Hi,

I would like a script to do fbackup and having gone thru the "man" pages and examples, I'm left with more questions and I hope someone would enlighten me. For example :

1) I would like to backup in LTO3. What parameters should I include in the config (-c switch)? What's the default if I do not include this? Do I need to worry about compression?

2) If I do not include the -g option to include the graph, does it mean that nothing will be backed up? Likewise, if I were to include it, does it mean I have to specify all the path (i option) that's to be backed up?

Thanks in advance.

[James R. Ferguson · Accepted solution]

Hi:

Be sure to specify your own configuration file for 'fbackup'. The default values that you will otherwise obtain are out-dated and will generally give very poor performance during backup and recovery. Build a configuration file that looks something like:

blocksperrecord 4096
records 64
checkpointfreq 4096
readerprocesses 6
maxretries 5
retrylimit 5000000
maxvoluses 200
filesperfsm 2000

The manpages for 'fbackup(1M)' document the default settings which is what you will get in the *absence* of an explicily defined set.

These parameters are recorded onto the actual backup tape and are thus used for a 'frecover' session too.

Checkpoint records allow the salvage of a backup when a bad tape spot is detected, since the records contain information about the file being backed up. The 'filesperfsm' parameter controls the frequency with which Fast Search Marks (FSM) are written. Both checkpoint and FSM records affect performance. FSMs take a tape drive out of streaming mode thereby adding to backup time. Conversely, however, FSMs improve the time it take to recover a file from tape.

In general, if your backup consists of a high proportion of small files, increase the value for 'filesperfsm'. If your backup consists of a high proportion of large files, then decrease the 'filesperfsm' value.

Compression is done by the tape drive device and is highly data dependent.

As for the '-g' (graph) option, specify a graph file that looks like:

i /
e /cdrom
e /dvdrom

This would include *everything* in the root directory and below except CD and DVDROM mountpoints. You can freely include and exclude directories and files. You can include a directory at its base level and exclude subdirectories of it.

Regards!

...JRF...

[so.nimda]

Hi James,

Thanks for taking the time to provide the very detailed reply. :)

I will try out your suggestions.

Regards

[so.nimda]

Oh.. one more thing...

Does anyone know where else I can find documentation on fbackup and it's switches/options besides manpages?

I've downloaded the the HPUX Sys Admin Guide from hp.docs website but there's not much info there.

Appreciate any input.

Thanks

[Dennis Handly]

>Does anyone know where else I can find documentation on fbackup and it's switches/options besides manpages?

google finds HP-UX System Administration Tasks: HP 9000:
http://www.docs.hp.com/en/B2355-90672/ch09.html
Backing Up Your Data Using HP-UX Commands
http://www.docs.hp.com/en/B2355-90672/ch09s08.html

[kate32]

Hi

I am using fbackup also and sent to a tape: here the entry that I put on my script and it is working as I have done a disaster recovery:
# Perform a full backup with FBACKUP HP-UX command
/usr/bin/mt -f /dev/rmt/0mn rew 1>>$LOG 2>>$LOG
/usr/sbin/fbackup -f /dev/rmt/0m -i / -e /var/spool/sockets/pwgr -I $logdir/index.fullbackup 1>$logdir/fbackup.msg 2>&1
success=$?

case $success in
0)
echo "BACKUP SUCCESSFUL"
/usr/bin/mt -f /dev/rmt/0mn offl 1>>$LOG 2>>$LOG
;;
4)
echo"BACKUP SUCCESSFUL ending with warnings. See logs $logdir/fbackup.msg "
/usr/bin/mt -f /dev/rmt/0mn offl 1>>$LOG 2>>$LOG
;;
*)
echo "ERROR: Return Code is $success BACKUP MAY HAVE FAILED !!!!!!!!!!!"
;;
esac

Cheers
K.

[Dennis Handly]

>kate32: here the entry that I put on my script
1>>$LOG 2>>$LOG

Minor improvement: 1>>$LOG 2>&1
When you dup (2>&1) a file, it uses the mode (>> append) from the first open.

[so.nimda]

Hi Dennis,

Thanks for the links.

I think this is the guide that I downloaded. :)

I'm specifically looking for info on parameters like 'blocksperrecord', 'records', etc and related config. As suggested by James in the earlier reply, the value of 4096 is used for LTO3. Is this value fixed for LTO3?

How do I know what value to use if I'm using say, DDS?

Regards

[so.nimda]

Hi kate32,

Thanks for the reply.

That's one heck of a script you have there !!

As a newbie to writing scipts, I think I need to "decipher" line by line what those commands do! :)

I'm sure it works successfully.

Regards

[James R. Ferguson]

Hi (again):

Since 'fbackup' is a proprietary HP tool, there is little information available. As far as I know, the Technical Knowledge Base is the best source of information beyond the public manpages.

The following links will give you insight into the internals of 'fbackup':

https://www2.itrc.hp.com/service/cki/docDisplay.do?docLocale=en&docId=emr_na-c01002358-4

https://www2.itrc.hp.com/service/cki/docDisplay.do?docLocale=en&docId=emr_na-c00908460-1

The document IDs are at the end of each URL.

As a side note, sadly, in my opinion, 'fbackup' is deprecated with release 11.31 and eventually will be phased out, although 'frecover' will persist to enable one to recover archives originally created with 'fbackup'. The standard Unix 'pax' command is considered a replacement.

Regards!

...JRF...

[so.nimda]

Hi James,

Thanks again for the reply.

It's sad news indeed... :( Just when I'm getting all interested in fbackup...

Rgds

[Bill Hassell]

Actually, there is no replacement for fbackup. pax, like tar and cpio, is a primitive tool to store files without any of the minimum requirements for a commercial backup program. For a workstation or a very small server, pax is OK. But for production with important data, pax just doesn't fulfill the requirements. Here are some of the features:

- no limit on file sizes
- provisions for busy and locked files
- multi-tape support
- hooks for tape changer handling
- frecover from parity errors on tape
- very high performance (up to 6 parallel processes)
- frecover can get any file in just a few minutes
- every tape has a complete index and can be read in seconds
- tapes have a label at the front to prevent accidental overwrite

Virtually all commercial backup programs like HP's Data Protector have these (and other) features. Note that an LTO3 places enormous performance requirements on your system (it's not just a long tape). Using fbackup with the above parameters will be the fastest solution.