Raid 0 + 1

[Ulf Lilleengen]

On man, okt 29, 2007 at 01:59:44 -0200, Felipe Neuwald wrote:
> Hi Folks,
> 
> I talked with my customer, and we decided to implement a 0 + 1 RAID,
> with 4 disks of 250Gb each.
> 
> Here is how my RAID is working now:
> 
> [root at fileserver /]# gvinum list
> 4 drives:
> D a                     State: up       /dev/ad4        A: 0/238474 MB (0%)
> D b                     State: up       /dev/ad5        A: 0/238475 MB (0%)
> D c                     State: up       /dev/ad6        A: 0/238475 MB (0%)
> D d                     State: up       /dev/ad7        A: 0/238475 MB (0%)
> 
> 1 volume:
> V data                  State: up       Plexes:       1 Size:        931 GB
> 
> 1 plex:
> P data.p0             S State: up       Subdisks:     4 Size:        931 GB
> 
> 4 subdisks:
> S data.p0.s0            State: up       D: a            Size:        232 GB
> S data.p0.s1            State: up       D: b            Size:        232 GB
> S data.p0.s2            State: up       D: c            Size:        232 GB
> S data.p0.s3            State: up       D: d            Size:        232 GB
> 
> 
> Could someone give me on example of how I'll implement a 0 + 1 RAID?
> 
Hello,

You need to create two plexes to do this, so something like:

drive a device /dev/ad4
drive b device /dev/ad5
drive c device /dev/ad6
drive d device /dev/ad7

volume data
plex org striped 493k # or some other stripesize
sd drive a
sd drive b

plex org striped 493k
sd drive c
sd drive d


Should do the trick. Also note that you can use a combination of gstripe(8) and
gmirror(8) to achieve the same effect.

-- 
Ulf Lilleengen