On Fri, 2014-01-10 at 17:36 +0000, Mathias Burén wrote:
> Hi all,
>
> I've a device that's part of an MD array:
>
> fdisk
> Disk /dev/sdg: 3000.6 GB, 3000592982016 bytes
> 255 heads, 63 sectors/track, 364801 cylinders, total 5860533168 sectors
> Units = sectors of 1 * 512 = 512 bytes
> Sector size (logical/physical): 512 bytes / 4096 bytes
> I/O size (minimum/optimal): 4096 bytes / 4096 bytes
> Disk identifier: 0x00000000
>
> $ sudo mdadm -E /dev/sdg
> /dev/sdg:
> Magic : a92b4efc
> Version : 1.2
> Feature Map : 0x0
> Array UUID : 0ad2603e:e43283ee:02180773:98e716ef
> Name : ion:md0 (local to host ion)
> Creation Time : Tue Feb 5 17:33:27 2013
> Raid Level : raid6
> Raid Devices : 6
>
> Avail Dev Size : 5860271024 (2794.40 GiB 3000.46 GB)
> Array Size : 7813531648 (7451.56 GiB 8001.06 GB)
> Used Dev Size : 3906765824 (1862.89 GiB 2000.26 GB)
> Data Offset : 262144 sectors
> Super Offset : 8 sectors
> State : clean
> Device UUID : 39c0b717:a9ca1dd7:bcba618f:caed0879
>
> Update Time : Fri Jan 10 17:28:31 2014
> Checksum : 53ea0170 - correct
> Events : 2668
>
> Layout : left-symmetric
> Chunk Size : 512K
>
> Device Role : Active device 4
> Array State : AAAAAA ('A' == active, '.' == missing)
>
> As you can see, Used Dev Size is lower than Avail Dev Size. Can I use
> the unallocated space by MD for storage somehow? As the devices in the
> array are used fully (no partitions) I guess not, but perhaps there is
> a way.
>
I'm wondering, did you perhaps add a drive after the initial creation
and forgot to grow the array to use the additional space? I believe that
adding a drive after creation causes the raid to spread the data over
all the drives via (I think) a re-shape which then needs a "grow" to
then extend to the end of the drives.
Actually thinking about it, 8GB would equate to 4 drives of 2TB each and
2 for redundancy = 6 drives total as noted in your post... is one of the
drives a 2 tb by mistake which would cause the 3tb drives to be limited
to the first 2tb... if they are all 3tb then I believe a grow=max size
(You'll need to double check the man page) should then use the un-used
space which will mean your array size should increase to 12TB (4*3TB+2
redundancy)
> Regards,
> Mathis
Jon.
--
To unsubscribe from this list: send the line "unsubscribe linux-raid" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
