On Friday 03 February 2006 00:11, Jerel Harwood wrote:
> >Fajar Priyanto wrote:
> >> Is it possible to setup a RAID 5 array using different size disks? Such
>
> as hda
>
> >> 9GB, hdb 36GB, hdc 40GB, hdd 80GB, hde 80GB.
> >
> >Gordon Messmer replied:
> >No, it isn't. RAID5, by design, requires units of the same size.
>
> Depending on what you are using to create the RAID5 (software vs.
> hardware.) It is possible to create a raid5 with the disk configuration you
> spec, but due to the nature of raid5 you will be wasting massive amounts of
> disk space as the max amount of disk space it will use per disk is directly
> relational to the smallest sized disk you use. Thus it will only use 9GB
> of the 36, 9GB of the 40 and 9GB of the 80GB drives each.
>
> You will only get 4 x 9GB = 36GB of disk space (disk 5 is used for Parity)
>
> Instead you could mirror (RAID1) the 2 80GB drives and put your critical
> data on them.
>
> -J Harwood
As far as different size drives from MDADM(8) ;
DESCRIPTION
RAID devices are virtual devices created from two or more real block
devices. This allows multiple devices (typically disk drives or partitions
there-of) to be combined into a single device to hold (for example) a single
filesystem.
