Add disk to existing RAID 0 Array

[Riaan Fourie]

I have a question using HP DL380 / DL585 servers. Separate to the root disks we have added 3 146 gb disks to the machine.

I have configured 1 disk to be a RAID 0 Array. What Iam trying to add an extra disk to the existing RAID 0 then convert it to a RAID 1 + 0 config.

Is this possible? Will I loose the data on the existing RAID 0 disk?

Iam asking the question, that is I was put in a situation where only 1 disk was shipped and I needed to install the OS, then Mirror up at a later stage?

[Tony Berry]

You will not be able to use the DL380 hardware RAID to do this, but you can use Linux LVM... as long as the RAID0/1 volume does not contain your /boot partition. Linux can only boot from a software RAID1.

If you'd like the exact steps for configuring this, please let me know and I'll paste them here.

If it were me, I'd find a way to backup your current data and use the built-in DL380 hardware RAID. You can get 500GB USB drives for $125 these days. Cheap temporary storage. Plus, when you're done with this project, you'll have a nice external drive for other projects.

[skt_skt]

Chaning the RAID lay out is destructive. But it is possible to boot from a hardware RAID too. Our case is a single disk in stripe mode

[skt_skt]

A correction. Its not a single disk. Two disks mirroed through h/w raid and looks to me like a sinlge disk from linux level

[Tony Berry]

If that's the case, you can still proceed by configuring the 3 new drives however you wish (RAID5 might be a good choice depending on your needs) at the hardware level, then striping them (RAID0) with Linux LVM. Once again, you can't boot from an RAID0 LVM partition though. The kernel cannot reside on a filesystem that requires a kernel driver to access... cart before the donkey scenario.

If it were my system, I'd add the 3 new drives as a hardware RAID5 and just mount it as a new partition, or a series of new partitions.

Aside from this whole issue, you really should be making regular backups anyway. There's more to data loss than a failing drive.