Backup & Restore plan using tar
 

I have been working in the Unix for 15 years but I am new to Linux. I am designing a backup and restore plan using tar. I have a few concerns.

Assuming the mysql databases are idle, will tar backup all that is necessary to get back up and running? All my tests say yes, but I wanted to confirm this.

If I backup the whole system (cd / ; tar cvf /dev/st0 .) when I try to restore this backup how do I deal with processes that are running whose binaries will not be overwritten? In Unix I generally avoid this backup method and just backup that data and necessary configuration files. It is not my first choice with Linux either.

If I just want to back up the data files and not the OS, how to I determine where the files that the servers and their respective GUI interface use are located? I am running Red Hat 9.0. I find little to no references to these files in the documentation. I hope I am just looking at the wrong documents. I ask this because I was only backing up /var/named on a name server and when I tested the restore plan I found that named did not work when this directory was restored.

If I use dd as below:
# Copy all but the label from disk to tape.
(dd bs=4k skip=1 count=0 && dd bs=512k) <$disk >$tape

# Copy from tape back to disk, but leave the disk label alone.
(dd bs=4k seek=1 count=0 && dd bs=512k) <$tape >$disk

What is the implication of system activity while the backup is running? I envision this producing a file system with serious issues. I see many suggestions to use dd for disk to disk backup, but I fear the same risk.

Thanks,

Mark Casazza

Re: Backup & Restore plan using tar
 

If you're restoring the system then you'll probably be booting using bootdisks or some such, so the running processes won't be from the binaries on the broken drive. Overwriting them shouldn't be a problem.

As far as configuration/data files and such for each specific application, you're probably going to have to look at documentation for each individual application. But as a guess, most configuration files or stored in either /etc or a .<app name> file/directory in your home directory.

To back up your named configuration you'll have to archive /etc/named.conf and probably you're entire /var/named/pz directory.