topic Re: Suggestion on backup Linux box? in Operating System - Linux

Suggestion on backup Linux box?

Jessica Chou — Wed, 01 Nov 2000 00:28:33 GMT

Hi! Anyone have suggestions on how to backup
linux box ? A tape drive?
So far I ftp data to a HP-UX, tar it onto a tape(DLT) with the rest of data on HP-UX.
But I don't know how to backup the OS part of Linux.

Thank you.

Jessica

Re: Suggestion on backup Linux box?

Albert E. Whale, CISSP — Wed, 01 Nov 2000 16:30:38 GMT

If you are happy with backing up the data in this manner, then I would recommend the following:

1. Keep an installation CD Handy for the OS of your choice.
2. Backup the /etc directory hierarchy as this is where Linux places most Configuration settings.

Now in the event of Disaster, you can recover easily by installing and recovering the /etc directory tree.

Have a Great Day!

Re: Suggestion on backup Linux box?

tony j. podrasky — Thu, 02 Nov 2000 01:35:40 GMT

I recommend adding a second I/O controller and disk.

This way, you can copy the data to the 2nd disk, and since it is on a 2nd controller you can boot off of it. This comes in real handy if you like to play "what if I do this?".

Re: Suggestion on backup Linux box?

Ralf Reinartz — Thu, 02 Nov 2000 11:40:18 GMT

Jessica,

With the Linux mdutils you can install a software raid (0,1 and I think 5). So you can reduce the chance for fatal error.

In additional you can install a SCSI Tape (dat or dlt) and you a sofawre like arkaia to backup your system.

so long

Ralf

Re: Suggestion on backup Linux box?

Kevin Ernst — Thu, 02 Nov 2000 18:20:43 GMT

Jessica:

If you don't want to buy another tape drive, you can make the 'tar' utility back up to a tape device on a remote system--assuming the protocol is compatible between Linux and HP-UX systems. (I've only done this with two HP-UX systems before.) Another option would be to temporarily NFS mount *all* of the Linux box's filesystems on the HP-UX system for the duration of the backup, and unmount them when you're done. You would probably want a pretty restrictive (only allow the HP-UX system access) '/etc/exports' file on the Linux system if you were to do this, for security reasons.

The former method (tar using remote tape device) would probably require you to have a separate tape for the Linux system's backups, or you would need to use the non-rewinding device file for your DLT (probably something like /dev/rmt/0mn) in order to be able to write multiple backup sets to a single tape. Writing multiple backup sets to a tape using 'tar' is usually more trouble than it's worth, though.

In order to back up to a remote tape device, the 'client' (in this case, Linux) system needs to be able to remote shell to the 'server' (the system with the tape drive) without giving a password. This might be a security concern at your site. You would need to modify the '~/.rhosts' file of an account on the server which has read/write permissions for the tape drive, or the '/etc/hosts.equiv' file. You can find more information on how to modify these files in the man pages for 'remsh' (HP-UX) or 'rsh' (Linux), and 'rlogin.'

Run 'rsh ' from the Linux client to make sure you can open a remote shell to the HP-UX system without giving a password. Once that's set up, you will need to issue the 'tar' command on the client, specifying a remote backup device, something like this...

tar cvf server.host.name:/dev/rmt/0m /

...where 'server.host.name' is the hostname of the HP-UX system, and '/dev/rmt/0m' is the device file of the tape drive on that system. That being done, the client remote shells to the server (using 'rsh'), runs a utility called 'rmt' to set up the connection to the remote tape device, and begins backing up the data across the network. It's magic--the entire process should be transparent to you. Until you need to *recover* the data, in which case you'll need to NFS mount the Linux box's filesystems (or physically attach the DLT) in order to 'untar' a previous backup.

Well, anyway. Two more options you might consider. =)