[DRBD-user] possible incorrect size of resource

Robin Kearney robin at kearney.co.uk
Sat Jan 12 23:15:18 CET 2013


Hi,

I've installed drbd version 8.3.13 on a couple of machines running centos
5.8. I already have data on a logical volume on the primary and I had no
space for a meta disk, so I've done the following:

* umount my data LV
* full fsck of the LV
* resize it down by 1GB
* mount it successfully and write to it for a few days without error

And then I created a second 1GB LV out of the same VG for later use as the
drbd meta disk.

And then tonight I did the following:

* unmounted my LV
* configured drbd to use meta data on a second LV (created out of the 1GB
now free in the VG)
* setup both primary and secondary
* started the syncing in the correct direction.

At this point everything looked good (watching /proc/drbd). I'm using
protocol A and the sync is going to take a few days.

Then I tried to mount /dev/drbd1 and use it, the mount worked ok but
writing to it changed it to be RO.

A bit of poking around shows that a fdisk -l of /dev/drbd1 shows a very
different size to that of the underlying LV:

[root at nhr-b02 /]# fdisk -l /dev/DataVG01/DataLV01

Disk /dev/DataVG01/DataLV01: 5988.1 GB, 5988119740416 bytes
255 heads, 63 sectors/track, 728014 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes

Disk /dev/DataVG01/DataLV01 doesn't contain a valid partition table
[root at nhr-b02 /]# fdisk -l /dev/drbd1

Disk /dev/drbd1: 4396.8 GB, 4396838551552 bytes
255 heads, 63 sectors/track, 534551 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes

Disk /dev/drbd1 doesn't contain a valid partition table

As you can see the drbd device is 1.5TB less than the underlying LV!

[root at nhr-b02 /]# lvdisplay  /dev/DataVG01/DataLV01
  --- Logical volume ---
  LV Name                /dev/DataVG01/DataLV01
  VG Name                DataVG01
  LV UUID                YoBNvQ-IP2p-tCh8-6rwp-emaq-QVYo-nrw4sI
  LV Write Access        read/write
  LV Status              available
  # open                 1
  LV Size                5.45 TB
  Current LE             1427679
  Segments               1
  Allocation             inherit
  Read ahead sectors     auto
  - currently set to     256
  Block device           253:2

This is the meta disk device, 1GB

[root at nhr-b02 /]# lvdisplay  /dev/DataVG01/DataLV01-meta
  --- Logical volume ---
  LV Name                /dev/DataVG01/DataLV01-meta
  VG Name                DataVG01
  LV UUID                hGkn51-vxpj-fz9N-t2Lh-GDOL-9nwe-PELT95
  LV Write Access        read/write
  LV Status              available
  # open                 1
  LV Size                1.00 GB
  Current LE             256
  Segments               1
  Allocation             inherit
  Read ahead sectors     auto
  - currently set to     256
  Block device           253:3

Does anybody know what is likely to cause this? I've halted the sync until
I can figure this out!

r.
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.linbit.com/pipermail/drbd-user/attachments/20130112/b45198dc/attachment.htm>


More information about the drbd-user mailing list