Linux RAID 1

[Mag0007]

Hello, I have a production linux server. Which has 2 identical drives. 1 of the harddrives is free, it has no filesystems or partitions. How can I mirrors this free drive to hdisk 1, without reinstalling linux or even rebooting?

Thanks!

 

[Mag0007]

Sorry my FDISK information is like this:
fdisk -l

Disk /dev/sda: 40.0 GB, 40000000000 bytes
255 heads, 63 sectors/track, 4863 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes

Device Boot Start End Blocks Id System
/dev/sda1 1 1306 10490413+ 83 Linux
/dev/sda2 1307 2612 10490445 83 Linux
/dev/sda3 2613 4763 17277907+ 83 Linux
/dev/sda4 4764 4863 803250 82 Linux swap / Solaris

Disk /dev/sdb: 40.0 GB, 40000000000 bytes
255 heads, 63 sectors/track, 4863 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes

Device Boot Start End Blocks Id System

 

[thedaver]

My understanding of building linux soft raid solutions is that the drive pair/set is reformatted when built. If you wanted to create a RAID pair from these drives, you should take steps to backup and restore.

Finally, software raid can be very hard on your system resources, particularly so with ext3 with adds more filesystem overhead.

Internet Directory

http://dir.surfinbox.com/dir.php/Top

 

[Mag0007]

Thanks. If I bought a PCI raidcard, would I still need to do a full reinstall? Is it possible to do this on a hardware level?

 

[thedaver]

Any raid you implement, hardware or software, will require a sector-based synchronization of the disks. Hardware moreso perhaps.

I don't know if a full reinstall is necessarily in the cards for you, but you'd need to look at the online references to doing a bare metal restore and you'll need to be able to tell the boot loader that the /boot partition lives on a new, raid partition.

Internet Directory

http://dir.surfinbox.com/dir.php/Top

 

[plamb]

Not sure about linux but all ohter nix's you can mirror at any time before during or after

 

[plamb]

http://willert.dk/geek/raid.html

 

[Mag0007]

I look at this before. But it seems he is creating the RAID devices during the installation. I want to create them after the installation.

 

[thedaver]

You can't.

Internet Directory

http://dir.surfinbox.com/dir.php/Top

 

[plamb]

http://www.tldp.org/HOWTO/Software-RAID-HOWTO.html