[DRBD-user] LVM and DRBD

[Roland Friedwagner]

Sorry my fault - /dev/vgsys/test02 was my testing lv.

On your system it should be:
write:
echo "HELLO" | dd of=/dev/drbd0 oflag=direct bs=512 cbs=512 conv=block
read:
dd if=/dev/drbd0 iflag=direct bs=512 count=1 | strings
=> HELLO
write:
echo "FOOBAR" | dd of=/dev/drbd0 oflag=direct bs=512 cbs=512 conv=block
read:
dd if=/dev/drbd0 iflag=direct bs=512 count=1 | strings
=> FOOBAR


It may clear things a bit if you provide us your drbd settings:
  drbdsetup /dev/drbd0 show | grep -v _is_default

And this one for lvm:
pvs --segments --units s -o 
vg_name,vg_extent_size,pv_name,pvseg_start,pvseg_size,lv_name,lv_size,lv_attr,pe_start,seg_pe_ranges

Roland

Am Mittwoch 16 Februar 2011 schrieb Etienne Pretorius:
> > Test this one:
> > ^^^^^^^^^^^^^^
> > write:
> > echo "HELLO" | dd of=/dev/vgsys/test02 oflag=direct bs=512 cbs=512
> > conv=block
>
> echo "HELLO" | dd of=/dev/vgsys/test02 oflag=direct bs=512 cbs=512
> conv=block
> dd: opening `/dev/vgsys/test02': No such file or directory
>
> Debian based machine, does not have /dev/vgsys at all. Looked for it
> on another debian based machine just to make sure.
>
> > read:
> > dd if=/dev/vgsys/test02 iflag=direct bs=512 count=1 | strings
> > =>  HELLO
> > write:
> > echo "FOOBAR" | dd of=/dev/vgsys/test02 oflag=direct bs=512 cbs=512
> > conv=block read:
> > dd if=/dev/vgsys/test02 iflag=direct bs=512 count=1 | strings
> > =>  FOOBAR



-- 
Roland.Friedwagner at wu.ac.at            Phone: +43 1 31336 5377
IT Services - WU (Vienna University of Economics and Business)