RAID - how to create RAID 1 without deleting data

dlugasx · 07-18-2009, 07:23 AM

Hello all,

I have a problem (like always

). Does anybody knows how can I create RAID 1+0 using two drives (one is with data and second one is new).

Is it possible to synchronize data drive with empty drive and create RAID 1+0 ?

help...

dlugasx

stress_junkie · 07-18-2009, 07:43 AM

The only reliable method of doing this is to start by backing up your data. Once you've got that you can recover from any unforeseen turn of events.

Next, the idea that you can derive a RAID 10 from two disks is just silly. You need a minimum of four disks to have a -functional- RAID 10. Trying to do this with two disks is more like emulating RAID than actually implementing it. I expect that the performance will be terrible.

Lastly, keep your configuration simple. Software RAID stinks. Fake RAID stinks. Only pure hardware RAID makes any sense at all, but a good hardware RAID solution is very expensive.

dlugasx · 07-20-2009, 03:54 AM

Quote:

Originally Posted by stress_junkie

The only reliable method of doing this is to start by backing up your data. Once you've got that you can recover from any unforeseen turn of events.

Next, the idea that you can derive a RAID 10 from two disks is just silly. You need a minimum of four disks to have a -functional- RAID 10. Trying to do this with two disks is more like emulating RAID than actually implementing it. I expect that the performance will be terrible.

Lastly, keep your configuration simple. Software RAID stinks. Fake RAID stinks. Only pure hardware RAID makes any sense at all, but a good hardware RAID solution is very expensive.

Sorry miss understanding.

It must be RAID 1.

Server is real and also RAID controller is real.

So once again...

Is it possible to create RAID 1 if we have one disk with data and one empty drive ? I mean, is it possible to configure RAID 1 without formating both drives ?

tequilatram · 07-26-2009, 10:23 PM

I am in a similar situation and do not have a hardware RAID controller card, so I am planning on using software RAID (LVM).

The easiest way I have found is to:
(high level overview)

- create a new LVM-RAID partition on the new drive.
- create a new RAID 1 device with the new drive's partition and a missing one.
- copy the data from the original drive's partition to the new RAID 1 device.
- repartition the original drive's partition to a LVM-RAID type.
- add the original drive's new partition into the new RAID 1 device.

If anyone has a better way to do this, please let me know ...
-Tram