gvinum: problem for adding drives

[Olivier Cochard]

I try to use the 'sd length 0' for mirroring 2 disks of different size.
- ad0 is a 102Mb hard drive
- ad1 is a 204Mb hard drive

Then I use "concat" for obtain mirroring (chapter 19.6.2 "Increased
Resilience: Mirroring" of the FreeBSD handbook).

Here is the config file:
$ cat /var/etc/raid.conf
drive disk_ad0 device /dev/ad0s1a
drive disk_ad1 device /dev/ad1s1a
volume titi
plex org concat
sd length 0 drive disk_ad0
plex org concat
sd length 0 drive disk_ad1

Normally, I should have one volume of 102Mb...

But gvinum create a volume of 204Mb...

Software RAID information and status:
2 drives:
D disk_ad1              State: up    /dev/ad1s1a    A: 0/204 MB (0%)
D disk_ad0              State: up    /dev/ad0s1a    A: 0/102 MB (0%)

1 volume:
V titi                  State: up    Plexes:       2    Size:        204 MB

2 plexes:
P titi.p1             C State: up    Subdisks:     1    Size:        204 MB
P titi.p0             C State: up    Subdisks:     1    Size:        102 MB

2 subdisks:
S titi.p1.s0            State: up    D: disk_ad1     Size:        204 MB
S titi.p0.s0            State: up    D: disk_ad0     Size:        102 MB

Then here are my question:
- Is 'concat' equivalent to mirroring ?
- Can I use a 'sd lenght 0' for disk with different size for 'concat' ?

Thanks,

Olivier



2006/3/15, Lukas Ertl <le at freebsd.org>:
>
> On Tue, 14 Mar 2006, Olivier Cochard wrote:
>
> > Is the 'sd length 0 drive' works for all RAID type ?
>
> Yes.
>
> regards,
> le
>
> --
> Lukas Ertl                         http://homepage.univie.ac.at/l.ertl/
> le at FreeBSD.org                     http://people.freebsd.org/~le/
>