[Drbd-dev] DRBD 8.4.3 : create-md possibly broken for fixed sized (shared) meta devices

[Lars Ellenberg]

On Wed, Mar 06, 2013 at 03:24:36PM +0100, Tijs Van Buggenhout wrote:
> Hi,
> 
> I recently installed drbd 8.4.3 packages and ran into problems when trying to 
> create a drbd resource using fixed size drbd meta device ided by an index. 
> Investigating further, it seems that when using a flexible meta disk, there is 
> no problem whatsoever.
> I also used the same configuration file/set of commands on the previous 
> version (8.4.2) for fixed size meta-disk, which worked without problems.
> 
> The following excerpt from the console log shows how I first create a drbd 
> resource (drbd0) with flexible meta disk (/dev/lv/drbd-meta-84). Afterwards I 
> undo the configuration, and try to do the same for fixed drbd meta disk, which 
> fails (every time). Then I roll back to the previous version of drbd 
> utils/module, and try the setup with fixed drbd meta disk again, which 
> succeeds.

> resource drbd0 {
>         on master.domain.com {
>                 device /dev/drbd0;
>                 disk /dev/lv/data;
>                 address 172.16.1.179:7788;
>                 meta-disk /dev/lv/drbd-meta-84 [0];

> (master.domain.com):~# dd if=/dev/zero of=/dev/lv/drbd-meta-84 bs=$[1024*1024] 
> (master.domain.com):~# modprobe drbd
> (master.domain.com):~# cat /proc/drbd 
> version: 8.4.3 (api:1/proto:86-101)
> GIT-hash: 89a294209144b68adb3ee85a73221f964d3ee515 build by root at build, 
> 2013-03-05 15:10:01
> (master.domain.com):~# drbdsetup new-resource drbd0
> (master.domain.com):~# drbdsetup new-minor drbd0 /dev/drbd0 0
> (master.domain.com):~# drbdadm create-md drbd0 -vvvvvvvvvv
> (master.domain.com):~# drbdadm attach drbd0
> 0: Failure: (119) No valid meta-data signature found.
> 
>         ==> Use 'drbdadm create-md res' to initialize meta-data area. <==

D'oh.
That is embarrassing.

I wonder why the regression tests using "old style indexed fixed size
external meta data" have not been exercised.

http://git.drbd.org/gitweb.cgi?p=drbd-8.4.git;a=commitdiff;h=82cf5feada2e4d0f536af5f6f377bd0f3fac1236

Thanks,

-- 
: Lars Ellenberg
: LINBIT | Your Way to High Availability
: DRBD/HA support and consulting http://www.linbit.com

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