Wednesday, July 18th, 2012, 6:44 pm
Backing Up Bootloader and Home Directories Over the Network
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ackups that are robust and resistant to disasters like fire should be distributed. Backing up by writing to external drives is good, but it is not sufficient. Here is how I back up my main machine. Backup is quick in a smaller number of rather large files (not too large as some file systems cannot cope with those), so one trick goes like this:
sudo mkdir /media/backupdrive/`date +%Y-%m-%d` # (if disk space permits, or via external mounted drive for another safety net) sudo tar -cf - /home/|split -b 1000m - /media/backupdrive/`date +%Y-%m-%d`/Home-`date +%Y-%m-%d`.tar.
This includes all the hidden files.
To reassemble:
cat *|tar -xf
this is then scp‘d or rsync‘d over to another box based on a wildcard or directory like
/media/backupdrive/`date +%Y-%m-%d`
This leaves a stack of backups in case the latest one is already ‘contaminated’. rsync of the original files, uncompressed and untarred, can be fast except for the first time, but for a stack of backups it’s not suitable.
But more files need to be backed up, depending on the bootloader for instance.
MBR backup and restore is done with dd:
dd if=/dev/sdX of=/tmp/sda-mbr.bin bs=512 count=1 dd if= sda-mbr.bin of=/dev/sdX bs=1 count=64 skip=446 seek=446
If this is saved to the home directory, then it’s included in the main backup.
