FBACKUP Problem

[Arun Jain]

Dear All,

please let me know what happens if we unmount the filesystems when the backup is running.
Is there any chances of data loss or data corruption. What will happen to the backup if we don't kill it.
What is the solution, to prevent data loss/corruption if their is any possibility.

Regards :
Arun

[James R. Ferguson]

Hi Arun:

You can't unmount the filesystems you are copying with 'fbackup'. The 'fbackup' utility operates *ON* filesystems that are mounted.

By default, up to five (5) copy retires are made for files that are found to be actively changing as 'fbackup' runs. This is governed by the 'maxretries' variable in the 'config' file. See the manpages for 'fbackup' for more information.

If after the maxiumum number of retries (per file), a static image of the file cannot be copied to tape, copy of the file on the tape is marked "bad". In this case, it cannot be recoverd witih 'frecover'. Retried and/or skipped files are logged as such by the 'fbackup' session.

Under NO CIRCUMSTANCES, use a 'kill -9' to stop an 'fbackup'. To do so will leave shared memory segments orphaned on your server, leading to lost memory.

Regards!

...JRF...

[TTr]

When fbackup starts it generates a list of all files that will be backed up, including the ones in the filesystem that you want to unmount.

If fbackup is reading files from this filesystem, you will not be able to unmount it.

If somehow you are able to unmount it, you will get many errors from fbackup for all the files in the fbackup list that are from this filesystem.

There will be no data corruption, just a lot of errors in fbackup. Your unmounted filesystem will not be in the fbackup.

[Dennis Handly]

>Is there any chances of data loss or data corruption. What will happen to the backup if we don't kill it.

Unless, it has already backed up that filesystem, it won't be backed up. There should be an error message.

>What is the solution, to prevent data loss/corruption?

Just restart it if you get those errors?

[Sajjad Sahir]

Dear Arun Jain
>>please let me know what happens if we unmount the filesystems when the backup is running.
during u backup u can't umount the filesystem.

Thanks and regards

Sajjad Sahir

[Rasheed Tamton]

Hi Arun,

fbackup normally gives messages when it encounters any errors such as [fbackup(1030): warnings encountered during backup], etc. fbackup writes index of all files selected for backup at the beginning. So, if those files are not backed up it gives error. YOu can use -v (verbose) option if you do it manually or using script with output to file.

A hanging fbackup process can be cleared by killing the pid.

Also check the -R (restart) option and the -I (index) option of frecover. By index option of frecover [frecover -I], you can check the what files are backed up to make sure that everything is ok.

Regards,
Rasheed Tamton.

[TTr]

On another thought why do you want to unmount a filesystem while fbackup is running? Is it because you don't want to back it up or it does not fit in the tape? The fbackup command has exclude options for that and you can exclude it by using the "-e path_to_be_excluded" option.

[Bill Hassell]

This is not an fbackup problem, it is a procedural error. It does not matter what computer system you are using. If you are running a full backup, removing files, directories or complete mountpoints will mean loss of data on the backup tape. And unless you check the resultant backup using frecover -N, you will never know what has been missed.

A backup is a critical system activity and should only be done when the system is quiescent. Otherwise, files may be changed at different times and the relationships between files will be broken. This is especially true for databases.