[DRBD-user] Problem with drbd v8 - cannot create new device

[Michael Paesold]

Philipp Reisner wrote:
> Am Donnerstag, 6. April 2006 17:18 schrieb Michael Paesold:
> > I want to run drbd trunk r2131 on 2.6.16.1 (with Xen 3). The problem is
> > that I cannot create/attach a new drbd device. The same error has been
> > reported before:
> > http://lists.linbit.com/pipermail/drbd-user/2005-May/002951.html
> > http://lists.linbit.com/pipermail/drbd-user/2005-May/002956.html
> >
> > NB: the lower-level device is a lvm device (was easier to setup for 
> > testing
> > because I already had a disc configured and used as volume group).
>
> Very strange. Just a wild guess. Something with the buffer flushing
> does not work in xen.
>
> Try the following
>
> 1) crate the metadata
> 1a) dump it to some file
> 2) reboot the virtual machine
> 3) try to attach
> 3a) dump it to some file

Rebooting the whole server did not change the situation. It still fails to 
attach the device. The metadata as seen by "drbdadm dump-md" does not change 
at all. NB I have already updated to last nights r2141.

I have narrowed the possible issues down by:
- using regular partitions (instead of LVs)
- using only /dev/drbd0
- using only the first slice of a partition as meta-disk (/dev/sdb2[0])

The only difference now is a new error message at "attach" (in syslog and on 
the serial console) about an unexpected md_size (messages in original 
sequence):
drbd0: disk( Diskless -> Attaching )
drbd0: unexpected md_size: 262144 (expected 6313545)
drbd0: disk( Attaching -> Diskless )
drbd0: drbd_bm_resize called with capacity == 0

fdisk -l /dev/sdb:
   Device Boot      Start         End      Blocks   Id  System
/dev/sdb1               1        1825    14659281   83  Linux
/dev/sdb2            1826        2218     3156772+  83  Linux

And:
      device    /dev/drbd0;
      disk      /dev/sdb1;
      meta-disk /dev/sdb2[0];


Additionally, I have now tried this with the stock 2.6.9-34.ELsmp (RHEL4 
up3) kernel. I get the very same error. So it seems this has nothing to do 
with Xen.

Here is again a summary of an strace of drbdsetup at "drbdadm attach" (of 
what I though was useful information):
...
open("/dev/drbd0", O_RDONLY)            = 3
...
ioctl(3, 0x80044400, 0xbfe32600)        = 0
...
open("/dev/sdb1", O_RDWR)               = 5
fstat64(5, {st_mode=S_IFBLK|0660, st_rdev=makedev(8, 17), ...}) = 0
open("/dev/sdb2", O_RDWR)               = 6
fstat64(6, {st_mode=S_IFBLK|0660, st_rdev=makedev(8, 18), ...}) = 0
ioctl(3, 0x40284406, 0xbfe325b0)        = -1 EINVAL (Invalid argument)
write(2, "ioctl(,SET_DISK_CONFIG,) failed:"..., 50) = 50
write(2, "No valid meta-data signature fou"..., 95) = 95

I am going to try with meta-data internal now.
Is there anything else I can do to find out what's going on here?

Best Regards,
Michael Paesold