[DRBD-user] "dd" meta-data when DRBD's role is Primary or Secondary

[Junko IKEDA]

Hi,

I'm trying to confirm whether DRBD + Heartbeat cluster can put up with
the following scenario.

(1) startup DRBD + Heartbeat
     Active node's role: Primary
     Standby node's role: Secondary

(2) crash the meta-data
     call "dd" command on the both of Active and Standby node like this;
     They have internal meta-data on /dev/cciss/c0d0p6.

     # dd if=/dev/zero of=/dev/cciss/c0d0p6 count=100000

after that, nothing has happened.
Active node kept running its service,
and after stopping Active node, Standby node took over the service.
This behavior is not a problem,
but I just want to know whether DRBD can keep its meta-data on
memory(?) if DRBD's role is Primary or Secondary.

If I down the DRBD's resource and "dd" the meta-data,
it seemed that meta-data was crashed, and I needed to recreate it.
# drbdadm down all
# dd if=/dev/zero of=/dev/cciss/c0d0p6 count=100000
# drbdadm up all
    ---> Failed!
# drbdadm create-md all

Thanks,
Junko

NTT DATA INTELLILINK CORPORATION