[CentOS] Expanding RAID 10 array, WAS: 40TB File System Recommendations

[John R Pierce]

On 04/13/11 9:51 PM, Emmanuel Noobadmin wrote:
> I'm was stuck trying to decide whether to go for the cheaper RAID 5
> setup and possibly getting killed by the IOPS penalty and the risk
> associated with rebuild time, or figure out a way to use the
> recommended RAID 10 setup with a smaller usable capacity for the
> budget but do so with the ability to expand in the near future. So
> really hoping that it could be done.

since this is the centos list, I really didn't want to suggest this, but 
if I was building a 20 or 40TB or whatever storage server, I do believe 
I'd be strongly consider using Solaris, or one of its variants like 
OpenIndiana, with ZFS.

ZFS was engineered from the ground up to scale to zetabytes

# zpool create archive mirror c2t0d0 c2t1d0 mirror c2t2d0 c2t3d0 mirror 
c3t0d0 c3t1d0 mirror c3t2d0 c3t2d0 ..... spare c?t?d0 c?t?d0

done.  available for use in a few seconds.  default mountpoint is /archive

# zfs create -o mountpoint=/u01 archive/u01
# zfs create -o mountpoint=/u02 archive/u02

creates a couple more filesystems that share the free space, mounted as 
/u01 and /u02

adding more disks?

# zpool add archive mirror c7t0d0 c7t1d0 mirror c7t2d0 c7t3d0