rainer wrote:
Kanwar Ranbir Sandhu wrote:
Hi All,
I have an external drive cage which has been configured with two
separate RAID 5 arrays. I then used LVM to create two PVs, and then
added the volumes together under one VG. The whole shebang is mounted
on one file system (/srv).
What would happen if one of the RAID arrays failed (e.g. two drives die
in RAID 5 array 1)? Would the data be safe, would I lose all data, or
would I just lose the data that was on the failed array?
I believe I would only lose the data on the failed array, but a friend
believe I would lose the whole lot.
Thanks in advance!
Regards,
Ranbir
> Hi,
>
> I suppose you have only made a JBOD with LVM - no further RAID0 or such.
>
> With JBOD, at least the data on the left RAID5-set should be safe. The
> data on the failed array and the bits and pieces which were on both
> arrays would be lost. Fragmentation and the size of data could be an
> issue - e.g. a 200 GB file on 2 x 160GB arrays would mean more than half
> is lost... ;(
>
> I think your friend meant you had made a RAID0 above the RAID5-sets,
> which would indeed mean the whole thing would be lost.
>
> Regards,
> rainer
>
To add to this.
A RAID 5 array is dependent on the number of drives where the data is
spread across. If there are 3 drives, then two failures is more than
enough. If you have 6 drives, then two drives may be okay.
It would be more useful to explain the RAID setup with the hardware,
number of drives per RAID and how they are configured.
--
Robin Laing
