Note: "permalinks" may not be as permanent as we would like,
direct links of old sources may well be a few messages off.
On Tue, Jul 27, 2010 at 11:06:42PM +0900, Junko IKEDA wrote: > 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. assuming you have a partition table on sda, and you do grep sda /proc/partitions dd if=/dev/zero of=/dev/sda bs=4k count=1 grep sda /proc/partitions "nothing has happened" either, but your next reboot won't get very far. Assuming you have some decent ram, and run find /mntpoint -ls > /dev/null to get a not too large file system dentry and inodes into the cache. then you dd if=/dev/zero of=/underlying-block-device, you will still be able to cd, and maybe even ls -l and stuff, as long as it stays in the cache. > 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. No. It knows about its _state_, and on state changes, writes (part of) that state to stable storage. > 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 So what? What are you going to prove here? That you are able to use dd to damage your system? No news in that. Sorry, but this is ridiculous. I really don't see where this should be going. -- : Lars Ellenberg : LINBIT | Your Way to High Availability : DRBD/HA support and consulting http://www.linbit.com DRBD® and LINBIT® are registered trademarks of LINBIT, Austria. __ please don't Cc me, but send to list -- I'm subscribed