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
gunzip /mnt/backup.gz – | dd of=/dev/wd0a
The SystemRescueCd has all sorts of useful tools to restore ailing Linux systems.
Check it out at: https://www.sysresccd.org
Categories: Uncategorized boot, centos, grub, grub2, linux, lvm, lvm2, raid, recover, redhat, rescue, restore, rhel, system, ubuntu
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> root (hd0,0)
Filesystem type is ext2fs, partition type 0xfd
grub> 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