[CentOS] Re: RAID, LVM, extra disks...

Thu Nov 29 16:25:32 UTC 2007
Ugo Bellavance <ugob at lubik.ca>

Alain Spineux wrote:
> On Nov 29, 2007 4:21 PM, Ugo Bellavance <ugob at lubik.ca> wrote:
>> Alain Spineux wrote:
>>> On Nov 29, 2007 6:59 AM, Ugo Bellavance <ugob at lubik.ca> wrote:
>>>> Hi,
>>>>
>>>>         This is my current config:
>>>>
>>>> /dev/md0 -> 200 MB -> sda1 + sdd1 -> /boot
>>>> /dev/md1 ->  36 GB -> sda2 + sdd2 -> form VolGroup00 with md2
>>>> /dev/md2 ->  18 GB -> sdb1 + sde1 -> form VolGroup00 with md1
>>>>
>>>> sda,sdd -> 36 GB 10k SCSI HDDs
>>>> sdb,sde -> 18 GB 10k SCSI HDDs
>>>>
>>>> I have added 2 36 GB 10K SCSI drives in it, they are detected as sdc and
>>>> sdf.
>>>>
>>>> What should I do if I want to optimize disk space?
>>>>
>>>> The simplest solution would be to create /dev/md3 out of sdc1 and sdf1,
>>>> and add it to the VG, and increase the size of my /vz logical volume.
>>>>
>>>> However, if I could convert that to a RAID5 (it could be possible to
>>>> re-install, but I would rather not), I could have 6 drives in RAID5, so
>>>> I'd have 5x36 GB (180) of space available total, instead of 3*36 (108).
>>> 180, you mean 2 X 5x18
>> Oh, I just realized I have 2X18 and 4X36.  I have 2 other 36 GB HDD
>> here.  Maybe I could have a 6x36 RAID5 this way.  Does it matter if I
> 
> drop the 2x18, to drop the 2x18 complexity,
> or keep them in mirroring, and maybe on another VG,
> to backup/store more critical data

Ok, but the server can only have 6 HDD.

So, first step, how would I replace the current 2X18 by the 2x36 that I 
put in the server yesterday?

(BTW thanks a lot for your help, it is very interesting)

Regards,

Ugo