Le vendredi 05 décembre 2008 à 20:22 +0000, Bob Williams a écrit :

...

Hi,

I have two 1TB disks configured as a Linux software RAID1 array and mounted on /home. There is 385GB free space. I am about to get a new machine, which will come with a 1TB disk. After I've removed Windows Vista from this disk I would like to add it to the array. If I stay with RAID1, I'll gain some redundancy, but no extra storage space. That's cool, as I've still got that 385GB free space. I have another, smaller disk to hold the OS partitions.

However, at some stage it might be better to configure the three disks as RAID5. Is it possible to convert a RAID1 array into a RAID5 array without loss of data. If not, it might be better to do the conversion now, while I can still find space to backup /home.

I'd welcome some advice :)

Bob

On Fri, Dec 5, 2008 at 4:44 PM, Jean-Christophe Baptiste wrote:

Hi,

I think you did not search much. A link I quickly found with google : http://mindache.net/wp/2008/02/18/raid1-to-raid5-with-lvm-resizing

This is well explained : it consists in creating a degraded RAID 5 with only 2 disks, transfer your data and then complete the RAID 5.

JC

That requires 4 disks, not the 3 asked about. If you have your data backed up, or otherwise recreate-able (and I hope you do). You can: degrade the 2-disk array to a single disk. Use the disk you just freed up and the new disk to build a degraded 3-disk raid-5. Migrate your data from the Raid-1 to the raid-5. Then destroy the raid-1 and add the last remaining disk into the raid-5. Personally, I'd buy a 4th drive and follow the procedure in the link. Greg -- Greg Freemyer Litigation Triage Solutions Specialist http://www.linkedin.com/in/gregfreemyer First 99 Days Litigation White Paper - http://www.norcrossgroup.com/forms/whitepapers/99%20Days%20whitepaper.pdf The Norcross Group The Intersection of Evidence & Technology http://www.norcrossgroup.com -- To unsubscribe, e-mail: opensuse+unsubscribe@opensuse.org For additional commands, e-mail: opensuse+help@opensuse.org

On Friday 05 December 2008 22:24:26 Greg Freemyer wrote:

That requires 4 disks, not the 3 asked about.

If you have your data backed up, or otherwise recreate-able (and I hope you do).

You can:

degrade the 2-disk array to a single disk.

Use the disk you just freed up and the new disk to build a degraded 3-disk raid-5.

Migrate your data from the Raid-1 to the raid-5.

Then destroy the raid-1 and add the last remaining disk into the raid-5.

Personally, I'd buy a 4th drive and follow the procedure in the link.

Greg

The new mainboard only has connectors for four SATA drives. I currently boot from a single (non-RAIDed) 250GB drive, which holds /, /usr, /var and swap, while /dev/md0 (the two 1TB drives) is mounted on /home. If I buy a fourth 1TB drive I'd also need to get a SATA controller card, plus I don't know that I need all that space at the moment. As it is I'll have to think how to partition the 2TBs (or will it be 3?) that I'll get from a 3 x 1TB RAID5 array. Many thanks for your advice. Bob -- Registered Linux User #463880 FSFE Member #1300 GPG-FP: A6C1 457C 6DBA B13E 5524 F703 D12A FB79 926B 994E openSUSE 11.0, Kernel 2.6.25.18-0.2-default, KDE 3.5.10 Intel Celeron 2.53GHz, 2GB DDR RAM, nVidia GeForce 7600GS -- To unsubscribe, e-mail: opensuse+unsubscribe@opensuse.org For additional commands, e-mail: opensuse+help@opensuse.org

On Saturday 06 December 2008 13:26:44 Carlos E. R. wrote:

On Saturday, 2008-12-06 at 09:28 -0000, Bob Williams wrote:

...

The new mainboard only has connectors for four SATA drives. I currently boot from a single (non-RAIDed) 250GB drive, which holds /, /usr, /var and swap, while /dev/md0 (the two 1TB drives) is mounted on /home. If I buy a fourth 1TB drive I'd also need to get a SATA controller card, plus

Not really. You can put it externally via usb. For example, you can backup your data to the external disk, then delete your existing raid and create the new one. You could even create a raid on two external disks via usb! Of course, slow. Better do two backups. Or you coud add a card for eSATA.

-- Cheers, Carlos E. R.

I'm beginning to realise just how many choices/decisions there are :) -- Registered Linux User #463880 FSFE Member #1300 GPG-FP: A6C1 457C 6DBA B13E 5524 F703 D12A FB79 926B 994E openSUSE 11.0, Kernel 2.6.25.18-0.2-default, KDE 3.5.10 Intel Celeron 2.53GHz, 2GB DDR RAM, nVidia GeForce 7600GS -- To unsubscribe, e-mail: opensuse+unsubscribe@opensuse.org For additional commands, e-mail: opensuse+help@opensuse.org