UNIX for Dummies Questions & Answers

Hi guys need your help!.... i'll have to do a backup of the entire files systems of the one server , but i have to do to another server because we do not have a tape device or some, do you know what instruction i have to use?
the backup server is a linux box and the server to being backup is a solaris.
Thanks in advance!

- Share your file system with NFS.
- mount drive on remote host and then locally copy that data to other disk partition.

Advantage
- Doing network copy takes time hence mounting drive locally helps
- NFS copying is faster compare to other copying method.

- nilesh

Another way:

How to backup your hard drive (the type of format doesn't matter) using dd.

Boot to some rescue mode by using the install media (generally "linux rescue") otherwise enter rescue mode manually: Linux Recovery

Make sure not to be booted to your hard drive, nor to have any of those partitions mounted.

Now use any combination of dd, ssh or rsh, gzip or bzip2 to backup the drive (I recommend using ssh versus rsh; however, ssh is generally not available during the rescue mode, whereas rsh is available):

You can backup the whole drive (if you have enough space on your destination system) as follows (This method also grabs the MBR):

dd if=/dev/sda | rsh user@dest "gzip -9 >20030220-backup-sda.dd.gz"

A restore using this method would be as follows:

rsh user@dest "cat 20080220-backup-sda.dd.gz | gunzip" | dd of=/dev/sda

To backup individual partitions, be sure to grab the MBR because it contains the partition table, as well as any partitions you want to backup:

dd if=/dev/sda bs=512 count=1 | rsh user@dest "cat - > 20030220-backup-mbr.dd"
dd if=/dev/sda1 | rsh user@dest "gzip -9 > 20030220-backup-sda1.dd.gz"

A restore would go as follows - be sure to restore the MBR, reboot, then restore the other partitions.

rsh user@dest "cat 20030220-backup-mbr.dd" | dd of=/dev/sda
reboot to re-read partition table (come back into rescue mode)
rsh user@dest "cat 20030220-backup-sda1.dd.gz | gunzip" | dd of=/dev/sda1

Depending on which machine is the fastest and how fast your network is, you need to decide when you will do the compression. Your choices are to compress before sending over the network, but if this machine is much slower than the server you are sending to, then it may be better to send the uncompressed data over the network to the destination server and compress as the data arrives. Just keep in mind that the transfer over the network will be a little slower if sending uncompressed data rather than compressed -- also the network speed affects this too -- 10 Mbit vs. 100 Mbit. Use your best judgement.

Thanks...do you have the commands about how i can do that?

Why sending the whole stuff over the wire to compress only afterwards?
Ok, one reason could be the box to be backed up hadn't enough processing resources currently.
But is wasting bandwidth really the better choice?
How about doing the compression first?

Code:

dd if=/dev/sda | gzip -c9 | rsh remuser@remhost 'cat >whateveryoulike.gz'

But dd maybe isn't the best of coices, and if so one should possibly try a bigger than default block size.
On non-Linux systems I usually would go for the dump/restore siblings of the used filesystem type. But Linux's dump/restore I think was notorious for being broken (but maybe not anymore?)
If the disk or single partitions of it weren't almost fully used up
you can really speed things up by using one of those clonefs* tools which come with distros like Insert (have forgotten their exact name)
because they would only copy actually allocated blocks.

Excellent point... But I typically use this when directly connected anyway, via crossover cable. And the PC im connecting to is typicaly alot faster. So network traffic is not an issue in that case. But compression BEFORE the copy would make more sense in network connected machines.

parted is another good option.
well, its actually a ncurses front end for dd y [bg]zip with some nice extra options