• 1 reply
  • Latest Post - ‏2011-04-02T01:31:38Z by ishields
3 Posts

Pinned topic Resizing a FS problem - RHEL 5.3

‏2011-03-08T07:52:01Z |
Hi Everybody.

I've been having a problem to resize a LUN presented to a Linux RHEL 5.3 server from a DS5020 Storage system.

I've resized the same LUN a few times before on the same server using the "hot_add -c" command then the "pvresize" command and resizing the LV and finally extending the FS with "resize2fs" and haven't had any problems.

Now I'm having this issue:

  • When I issue the "multipath -ll" command I got the following:

# multipath -ll mpath2 (360080e500017debe000004d94b50642b) dm-7 IBM,VirtualDisk [size=900G][features=0][hwhandler=1 rdac][rw]

This line shows that the LUN sees the new size presented from the SAN; 900GB

\_ round-robin 0 [prio=100][active] \_ 3:0:0:2 sdc 8:32  [active][ready] mpath1 (360080e500017d386000007fb4b54a2c2) dm-0 IBM,VirtualDisk [size=15G][features=0][hwhandler=1 rdac][rw] \_ round-robin 0 [prio=100][active] \_ 3:0:0:1 sdb 8:16  [active][ready] mpath0 (360080e500017d386000004df4b5063e4) dm-1 IBM,VirtualDisk [size=20G][features=0][hwhandler=1 rdac][rw] \_ round-robin 0 [prio=100][active] \_ 3:0:0:0 sda 8:0   [active][ready] mpath4 (360080e500017debe00000e864b7fcf66) dm-8 IBM,VirtualDisk [size=60G][features=0][hwhandler=1 rdac][rw] \_ round-robin 0 [prio=100][active] \_ 3:0:0:4 sde 8:64  [active][ready]

  • But when I run a "pvscan" command I get this:

# pvscan PV /dev/sdf              VG VolGroup04   lvm2 [32.00 GB / 0    free] PV /dev/mpath/mpath2p1   VG VolGroup01   lvm2 [599.97 GB / 0    free]

The PV /dev/mpath/mpath2p1 which is actually the device that is registered on LVM that corresponds to the LUN in question just sees 600GB instead of the whole 900GB, is worth to mention that the device is also know as dm-9 instead as dm-7 as the multipath command reports

PV /dev/mpath/mpath4     VG VolGroup03   lvm2 [59.97 GB / 0    free] PV /dev/mpath/mpath0p2   VG VolGroup00   lvm2 [19.88 GB / 0    free] PV /dev/mpath/mpath1p1   VG VolGroup00   lvm2 [14.97 GB / 0    free] Total: 5 [726.78 GB] / in use: 5 [726.78 GB] / in no VG: 0 [0   ]

  • Finally, I don't know exactly what it means but if I use the commands "head -n 10 /dev/dm-7" and "head -n 10 /dev/dm-9" I see practically the same information with just one difference, the first thing the dm-9 "disk" shows is the legend "LABELONE" and the dm-7 disk not; here an example of the output:

# head -n 10 /dev/dm-9 LABELONE��

This line is the one that don't come up on the dm-7 "disk", aside from that, is all the same

LVM2 001ZMX1uKdkdPG8Ytiyx2fnaR7Wkad81Ccl�����
{+�� LVM2 x[5A%r0N*>���Z�VolGroup01 
{ id = 
"mjDZmd-1Hb9-zgrB-ceQi-RrGE-fKah-kD3Yql" seqno = 1 status = [
"WRITE"] flags = [] extent_size = 65536 max_lv = 0 max_pv = 0

Some important context info: The OS is RHEL 5.3 and the RDAC driver is installed.

I was considering running the "kpartx" command against the /dev/dm-9 disk, but I'm not fully aware of the possible consequences and/or if it will actually will make any difference.

I know that maybe you guys will need any more information to help me out, if so please let me know and I'll try to get it for you ASAP.

Thank you very much in advanced.

Best regards.
Updated on 2011-04-02T01:31:38Z at 2011-04-02T01:31:38Z by ishields
  • ishields
    988 Posts

    Re: Resizing a FS problem - RHEL 5.3

    I have posted all the ServeRAID information that I have in the posting Where to get support for IBM ServeRAID on Linux. Please use those resources for ServeRAID and disk subsystem support.

    Ian Shields