Re: [gentoo-user] Process to resize ext3 file system at the command line?

[J. Roeleveld]

On Fri, November 18, 2011 1:33 am, Mark Knecht wrote:
> On Thu, Nov 17, 2011 at 4:21 PM, Neil Bothwick <neil@××××××××××.uk> wrote:
>> On Thu, 17 Nov 2011 16:13:09 -0800, Mark Knecht wrote:
>>
>>> > Do you have separately partitioned drives with those partitions
>>> > arranged into single-partition arrays, or do you have one RAID device
>>> > that is then partitioned?
>>> >
>>> > If the latter, you should certainly work with the md device.
>>> >
>>> > I prefer to avoid all this confusion by creating a large, single
>>> > partition array that I use an an LVM physical volume.
>>>
>>> Separately partitioned drives arranged into RAID arrays.
>>
>> So you have three partitions arranged into a single RAID5 partition,
>> say /dev/md1?
>>
>> In that case, the size of /dev/md1 should already be correct and you
>> only
>> need to resize the filesystem and you should ignore my witterings about
>> fdisk that filed to take into account your use of RAID.
>> resize2fs /dev/md1 should be all you need, you shouldn't even need to
>> unmount the filesystem.
>>
>
> I have 3 partitions which were previously RAID-1. I've already failed
> one drive so at this moment it's a 2-drive RAID-1. I'm attempting to
> get those two remaining 2 partitions converted to RAID-5 the command
> suggested on the RAID list for doing that isn't working for me.
>
> Once the 250GB RAID-1 is converted to RAID-5 i have to add a new drive
> back in to become a 3-drive RAID-5. The drive I add will be the drive
> I just failed.
>
> c2stable ~ # mdadm --grow /dev/md6 --level=5
> mdadm: /dev/md6: could not set level to raid5
> c2stable ~ #
>
> c2stable ~ # mdadm -D /dev/md6
> /dev/md6:
>        Version : 1.1
>  Creation Time : Thu Apr 15 10:45:35 2010
>     Raid Level : raid1
>     Array Size : 247416933 (235.96 GiB 253.35 GB)
>  Used Dev Size : 247416933 (235.96 GiB 253.35 GB)
>   Raid Devices : 2
>  Total Devices : 2
>    Persistence : Superblock is persistent
>
>    Update Time : Thu Nov 17 13:27:20 2011
>          State : clean
>  Active Devices : 2
> Working Devices : 2
>  Failed Devices : 0
>  Spare Devices : 0
>
>           Name : c2stable:6  (local to host c2stable)
>           UUID : 249c7331:a8203540:c8f3b020:fb30a66b
>         Events : 1039
>
>    Number   Major   Minor   RaidDevice State
>       0       8        6        0      active sync   /dev/sda6
>       1       8       22        1      active sync   /dev/sdb6
> c2stable ~ #

I have never had to change a RAID-1 to RAID-5, but I would do it as follows:

1) Fail 2 drives from the RAID-1
2) Remove those 2 drives from the RAID-1
3) Create a new RAID-5 (with failed disk) using the 2 removed drives
4) Copy the data over from the RAID-1 to the RAID-5
5) Remove the RAID-1
6) Add the third drive to the RAID-5 and let it rebuild.

I don't know the commands for the above from memory, but I'm sure some of
this is in the man-page.

--
Joost

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