Chrille Asked: 2012-03-02 22:25:22 +0800 CST2012-03-02 22:25:22 +0800 CST 2012-03-02 22:25:22 +0800 CST Install sw RAID 1 on production server from single disk? 772 Is it possible to install software RAID 1 on a single disk Debian server without erasing/format the data on the original disk? What approach would you recommend? software-raid 1 Answers Voted Best Answer Gregory MOUSSAT 2012-03-02T23:16:24+08:002012-03-02T23:16:24+08:00 You can. I don't understand why you want only one disk, but you can. And this won't slow your disk accesses. You need to shrink the filesystem to make sure there is 128K free at the end of the device, because Linux software RAID need it: umount / resize2fs /dev/xxx your_size mdadm --create /dev/mdx --raid-devices=2 --level=raid1 /dev/xxx missing mount /dev/md0 /xxxxx I strongly suggest you to test it with a dummy computer or a virtual machine.
You can. I don't understand why you want only one disk, but you can. And this won't slow your disk accesses.
You need to shrink the filesystem to make sure there is 128K free at the end of the device, because Linux software RAID need it:
umount /resize2fs /dev/xxx your_size
mdadm --create /dev/mdx --raid-devices=2 --level=raid1 /dev/xxx missing
mount /dev/md0 /xxxxx
I strongly suggest you to test it with a dummy computer or a virtual machine.