Red Hat Bugzilla – Bug 510707
multipath manual for RHEL5 has no information on online resizing of a LUN
Last modified: 2009-09-03 12:47:16 EDT
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In the RHEL4 multipath manual there is an entry on how to resize a LUN while it is in use. This section was deleted for the RHEL5 version of the manual. Rightfully so because the RHEL4 instructions won't work on kernel 2.6.18/RHEL5. It is possible to resize a LUN while using it though, I wrote down how under "additional information".
Bugzilla component: Documentation-cluster
Book identifier: DM_Multipath(EN)-5 (2009-01-06T15:35)
Use the following procedure to resize an online multipath device.
1. Resize your physical device.
2. Find the paths to the LUN:
# multipath -l
3. Resize your paths. For SCSI devices, writing a 1 to the rescan file for the device causes the SCSI driver to rescan. You can use the following command:
# echo 1 > /sys/block/<device_name>/device/rescan
4. Resize your multipath device by running the multipathd resize command:
# multipathd -k'resize map mpath0'
5. Resize the filesystem (assuming no LVM or DOS partitions are used)
# resize2fs /dev/mapper/mpath0
Reassigned to primary writer, slevine.
I sent the following note to Ben Marzinski on July 15, since he's my main technical contact and reviewer here. As soon as I hear back from Ben on this I'll get it into the next revision of the document.
Could you look at Bug 510707 and verify whether the information there is correct -- and thus whether I should add this procedure to the Multipath document for RHEL 5.4?
Yes, this should work just fine. You can add it to the Multipath document.
I have added this procedure to the 5.4 draft and it will be in the RHEL 5.4 version when it is released.
I noticed that on http://www.redhat.com/docs/manuals/enterprise/ there was a document added: "Online Storage Reconfiguration Guide" dated July 15.
This doc does contain the resizing info. Maybe what would be handy is a link in the multipath manual that points to the new doc? Or consolidate the 2 docs?
(In reply to comment #5)
> I noticed that on http://www.redhat.com/docs/manuals/enterprise/ there was a
> document added: "Online Storage Reconfiguration Guide" dated July 15.
> This doc does contain the resizing info. Maybe what would be handy is a link in
> the multipath manual that points to the new doc? Or consolidate the 2 docs?
Thanks for pointing this out. I think I'll leave the procedure supplied here in the multipath manual and add a "for further information" reference to the online storage doc. I'm not sure I can make this an actual link, but I certainly can refer to the document in the manual which should point users to the document.
With the release of RHEL 5.4, I am closing this bug.