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* (unknown), 
@ 2002-12-28  1:25 TJ
  2002-12-28 12:39 ` RAID5 reconfig Marco Shaw
  0 siblings, 1 reply; 6+ messages in thread
From: TJ @ 2002-12-28  1:25 UTC (permalink / raw)
  To: linux-raid

Do the current raidtools allow enlarging a RAID 5 array by adding more disks
to it without initializing a new
array? This feature is found in some hardware raid controllers.

Even if the array must be taken down and processed while offline by a
utility, this would be greatly
appreciated.


^ permalink raw reply	[flat|nested] 6+ messages in thread

* Re: RAID5 reconfig
  2002-12-28  1:25 (unknown), TJ
@ 2002-12-28 12:39 ` Marco Shaw
  0 siblings, 0 replies; 6+ messages in thread
From: Marco Shaw @ 2002-12-28 12:39 UTC (permalink / raw)
  To: linux-raid

On Fri, 2002-12-27 at 21:25, TJ wrote:
> Do the current raidtools allow enlarging a RAID 5 array by adding more disks
> to it without initializing a new
> array? This feature is found in some hardware raid controllers.

Use with extreme care:
http://unthought.net/raidreconf/index.shtml

Someone posted a success story on this list a few weeks ago using a
pretty big RAID5 volume/array.

Marco

PS: Please use the 'Subject' field.


^ permalink raw reply	[flat|nested] 6+ messages in thread

* Re: RAID5 reconfig
@ 2002-12-28 16:43 TJ
  2003-01-20  0:19 ` Jakob Oestergaard
  0 siblings, 1 reply; 6+ messages in thread
From: TJ @ 2002-12-28 16:43 UTC (permalink / raw)
  To: linux-raid

> Use with extreme care:
> http://unthought.net/raidreconf/index.shtml

> Someone posted a success story on this list a few weeks ago using a
> pretty big RAID5 volume/array.

> Marco

> PS: Please use the 'Subject' field.

Sorry about that.. Please CC me, I don't seem to be getting any feed from
the list.

Thanks for the link. I've been reading up on others experiences and
documentation seems somewhat thin. Does a mini-HOWTO exist anywhere?
From what I've read, first raidreconf is used to change the array, then
fsck -f is run to check the product, then the file system resize utility
must be used to change the size of the filesystem on the RAID array. Then it
would probably be a good idea to run fsck -f once more. This should be
sufficient to add more disks to a RAID 5 array and enlarge the filesystem to
take advantage of the larger block device. Am I missing anything?


^ permalink raw reply	[flat|nested] 6+ messages in thread

* Re: RAID5 reconfig
  2002-12-28 16:43 TJ
@ 2003-01-20  0:19 ` Jakob Oestergaard
  2003-01-20  3:16   ` TJ
  0 siblings, 1 reply; 6+ messages in thread
From: Jakob Oestergaard @ 2003-01-20  0:19 UTC (permalink / raw)
  To: TJ; +Cc: linux-raid

On Sat, Dec 28, 2002 at 11:43:25AM -0500, TJ wrote:
> > Use with extreme care:
> > http://unthought.net/raidreconf/index.shtml
> 
> > Someone posted a success story on this list a few weeks ago using a
> > pretty big RAID5 volume/array.
> 
> > Marco
> 
> > PS: Please use the 'Subject' field.
> 
> Sorry about that.. Please CC me, I don't seem to be getting any feed from
> the list.
> 
> Thanks for the link. I've been reading up on others experiences and
> documentation seems somewhat thin. Does a mini-HOWTO exist anywhere?
> >From what I've read, first raidreconf is used to change the array, then
> fsck -f is run to check the product, then the file system resize utility
> must be used to change the size of the filesystem on the RAID array. Then it
> would probably be a good idea to run fsck -f once more. This should be
> sufficient to add more disks to a RAID 5 array and enlarge the filesystem to
> take advantage of the larger block device. Am I missing anything?

Only that in some scenarios raidreconf fails horribly - this seems to at
least happen if you have hot spares configured.

Make sure you have a good backup.  Please report success/failure to the
list - that is greatly appreciated  :)

-- 
................................................................
:   jakob@unthought.net   : And I see the elder races,         :
:.........................: putrid forms of man                :
:   Jakob Østergaard      : See him rise and claim the earth,  :
:        OZ9ABN           : his downfall is at hand.           :
:.........................:............{Konkhra}...............:
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^ permalink raw reply	[flat|nested] 6+ messages in thread

* Re: RAID5 reconfig
  2003-01-20  0:19 ` Jakob Oestergaard
@ 2003-01-20  3:16   ` TJ
  2003-01-20  3:48     ` Scott McDermott
  0 siblings, 1 reply; 6+ messages in thread
From: TJ @ 2003-01-20  3:16 UTC (permalink / raw)
  To: Jakob Oestergaard; +Cc: linux-raid

Well, raidreconfig worked wonderfully for me, however I screwed up
afterwards. I fscked before resize2fs, but forgot to do it again afterwards
and mounted the filesystem and used it. That caused it enough damage that I
damaged it and rebuilt it from backups. Raidreconfig worked excellently. It
handled unequal partition sizes just fine, though running it with the --test
flag returned an error that one partition was too small (0kb).

One feature request:

Go from 4 40gb disks in RAID 5 to 3 80gb devices in RAID 5: 1 80 gb disk and
the 4 40gb drives in RAID 0.


Old raidtab:

raiddev                        /dev/md0
raid-level                     0
nr-raid-disks                2
chunk-size                    64k
persistent-superblock   1
nr-spare-disks              0
    device                      /dev/hda4
    raid-disk                  0
    device                      /dev/hdc1
    raid-disk                 1

New raidtab:

raiddev                        /dev/md0
raid-level                      5
nr-raid-disks                4
chunk-size                   128k
persistent-superblock       1
parity-algorithm            left-symmetric
nr-spare-disks              0
    device          /dev/hda4
    raid-disk     0
    device          /dev/hdb1
    raid-disk     1
    device          /dev/hdc1
    raid-disk     2
    device          /dev/hdd1
    raid-disk     3


^ permalink raw reply	[flat|nested] 6+ messages in thread

* Re: RAID5 reconfig
  2003-01-20  3:16   ` TJ
@ 2003-01-20  3:48     ` Scott McDermott
  0 siblings, 0 replies; 6+ messages in thread
From: Scott McDermott @ 2003-01-20  3:48 UTC (permalink / raw)
  To: linux-raid

TJ on Sun 19/01 22:16 -0500:
> I fscked before resize2fs, but forgot to do it again afterwards and
> mounted the filesystem and used it.

You should not have to.  I have never used e2fsck after resize2fs and
have never had a problem with perhaps a couple dozen resizes.

^ permalink raw reply	[flat|nested] 6+ messages in thread

end of thread, other threads:[~2003-01-20  3:48 UTC | newest]

Thread overview: 6+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2002-12-28  1:25 (unknown), TJ
2002-12-28 12:39 ` RAID5 reconfig Marco Shaw
  -- strict thread matches above, loose matches on Subject: below --
2002-12-28 16:43 TJ
2003-01-20  0:19 ` Jakob Oestergaard
2003-01-20  3:16   ` TJ
2003-01-20  3:48     ` Scott McDermott

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