Posts Tagged ‘restore’

dd with gzip

January 16th, 2013 No comments

You can save a lot of space by compressing dd image files.
These examples use gzip but many other compression apps will work just as well.

backup with dd and gzip

dd if=/dev/wd0a | gzip -9 > /mnt/backup.gz

restore backup

gunzip /mnt/backup.gz – | dd of=/dev/wd0a

Categories: Linux, OS X Tags: , , , , , ,


December 31st, 2010 No comments

The SystemRescueCd has all sorts of useful tools to restore ailing Linux systems.
Check it out at:

Grub Recovery on CentOS 5 with RAID

December 30th, 2010 No comments

I recently replaced the RAID 1 drives in my CentOS 5 box and had to reinstall the grub MBR. As the drives are a couple of TB each, I thought I’d try GPT instead of the old MBR partitioning, since soon all drives will exceed MBR’s 2TB limit. Luckily GPT is baked into RH/CentOS kernels (unlike many others).
Restoring the MBR was trickier than I expected and I made a couple of mistakes along the way – wish I had found the following description sooner:

In a nutshell run grub interactively and do the following:

# grub
grub> root (hd0,0)        
root (hd0,0)
 Filesystem type is ext2fs, partition type 0xfd
grub> setup (hd0)
setup (hd0)
 Checking if "/boot/grub/stage1" exists... no
 Checking if "/grub/stage1" exists... yes
 Checking if "/grub/stage2" exists... yes
 Checking if "/grub/e2fs_stage1_5" exists... yes
 Running "embed /grub/e2fs_stage1_5 (hd0)"...  16 sectors are embedded.
 Running "install /grub/stage1 (hd0) (hd0)1+16 p (hd0,0)/grub/stage2 /grub/grub.conf"... succeeded
grub> quit
# reboot