Trials & Tribulations

Ok, this is defiantly worth writing… especially for new users

Here i will cover how to backup/restore (to file) FreeBSD using native utilities called dump and restore

note: dump and restore works only for UFS (aka FFS)

Backing up system

To backup system you need to use dump utility

backup:

$ dump -0Lauf /path/to/backups/ad0s1d.dump /dev/ad0s1d

Backup and compress on the fly

$ dump -0Lauf - /dev/ad0s1d | bzip2 > /path/to/backups/ad0s1d.dump

-0 – means to backup entire filesystem

-f name – output to file/device, or to stdout if you use -

-a – you need this if you output to file.

-L – needed if you backup mounted filesystem

Restoring system

to restore system restart in single user mode

format filesystem that you want to restore

in backup example, we backed up /dev/ad0s1d, so let’s format it now

$ newfs -U /dev/ad0s1d

now you need to mount it

$ mkdir /mnt/target
$ mount /dev/ad0s1d /mnt/target

Let’s imagine you backed up files to usb stick (da0, in root directory)

we need to mount it

$ mount -t msdosfs /dev/da0 /mnt/usb

create symbolic links from /tmp and /var/tmp to that mount point

now to restore from backup you need to cd to dir where you mounted partition that you want to restore

$ cd /mnt/target

to restore from uncompressed backup

$ restore -rf /mnt/usb/ad0s1d.dump

to restore from compressed backup

$ bzcat /mnt/usb/ad0s1d.dump.bz2 | restore -rf -

And that is it

now you can delete file dumpdates (or something like that, check for weird file in target directory, in our case /mnt/target)

now unmount filesystems and reboot

Some notes

you can do incremental backups – backup everything and then backup only files that have changed since (on current backup level) see manual for more info

you can use dump/restore to clone your system to other PC’s

you will probably need to copy Master Boot Record (MBR) as well

to backup MBR:

$ dd if=/dev/ad0 of=/path/to/mbr.img bs=512 count=1

to restore MBR:

$ dd if=/path/to/mbr.img of=/dev/ad0 bs=512 count=1

Tips

* I prefer to compress backup, you can guess why

* if you backup /usr you may delete content of ports directory

this will speed up backup process, and reduce size of backup…

It’s good thing because by the time you will restore /usr from backups

/usr/ports will be outdated, and you will need to update them anyway.

And portsnap works very well (fast) in fetching ports

* I prefer to do full backups, that way you can be 100% sure, there won’t

be any confusing situations

* if you want to do backups while using filesystem, make sure you haven’t

deleted .snap directory, on partition that you want to backup

* if you have backed up encrypted drive, you need to somehow encrypt backups

because if someone gets these files, he can restore them to his pc, and read your files at will. (I used this method in FreeBSD + Geli guide, to encrypt drive, but process can be reversed)

Resources

dump(8)

restore(8)

Update 1

Moving system

You can move system from disk to disk on fly with

$ newfs -U /dev/ad2s1a
$ mount /dev/ad2s1a.... /target
$ cd /target
$ dump -0Lauf - /dev/ad1s1a  | restore -rf -

you can do the same using sudo

$ sudo echo
$ sudo dump -0Lauf - /dev/ad1s1a  | sudo restore -rf -

Update 2

as OpenBSD suggests using gzip instead of bzip2 will seed up compression at cost of larger (very little) archives

so now i suggest using gzip to compress and zcat to uncompress on fly

I’ve tested it, and i was amazed.

No more Bzip2 for me

STOLEN FROM HERE

BACKUP BASICS