Note: "permalinks" may not be as permanent as we would like,
direct links of old sources may well be a few messages off.
I see the Manual Failover section of the DRBD 8.4.x manual, and I see that it requires that the file system be umounted before attempting to promote and mount the file system on the secondary. What I meant by "those status flags" in my first message is that when a node mounts a file system, that file system is marked as mounted somewhere on that device. The "mounted" status flag is what I'm trying to describe, and I'm not sure if I have the correct name for it. Does pacemaker or manual failover handle the case where a file server experiences a hard failure where the umount operation is impossible? How can the secondary copy of the file system be mounted if the umount operation never occurred and cannot occur on server1? -James Ault, http://www.linkedin.com/in/aultj/ http://tinyurl.com/link2jimault <http://tinyurl.com/link2jimault> Life's Biggest Decision is... <http://www.bornofthespirit.today/> On Thu, Jul 7, 2016 at 10:48 AM, Lars Ellenberg <lars.ellenberg at linbit.com> wrote: > On Thu, Jul 07, 2016 at 07:16:51AM -0400, James Ault wrote: > > Here is a scenario: > > > > Two identical servers running RHEL 6.7, > > Three RAID5 targets, with one Logical volume group and one logical volume > > defined on top of each target. > > A DRBD device defined on top of each logical volume, and then an XFS file > > system defined on top of each DRBD device. > > > > The two identical servers are right on top of one another in the rack, > and > > connected by a single ethernet cable for a private network. > > > > The configuration works as far as synchronization between DRBD devices. > > > > We do NOT have pacemaker as part of this configuration at management's > > request. > > > > We have the XFS file system mounted on server1, and this file system is > > exported via NFS. > > > > The difficulty lies in performing failover actions without pacemaker > > automation. > > > > The file system is mounted, and those status flags on the file system are > > successfully mirrored to server2. > > > > If I disconnected all wires from server1 to simulate system failure, and > > promoted server2 to primary on one of these file systems, and attempted > to > > mount it, the error displayed is "file system already mounted". > > > > I have searched the xfs_admin and mount man pages thoroughly to find an > > option that would help me overcome this state. > > > > Our purpose of replication is to preserve and recover data in case of > > failure, but we are unable to recover or use the secondary copy in our > > current configuration. > > > > How can I recover and use this data without introducing pacemaker to our > > configuration? > > If you want to do manual failover (I believe we have that also > documented in the User's Guide), all you do is > > drbdadm primary $res > mount /dev/drbdX /some/where > > That's also exactly what pacemaker would do. > > If that does not work, > you have it either "auto-mounted" already by something, > or you have some file system UUID conflict, > or something else is very wrong. > > > -- > : Lars Ellenberg > : LINBIT | Keeping the Digital World Running > : DRBD -- Heartbeat -- Corosync -- Pacemaker > > DRBD® and LINBIT® are registered trademarks of LINBIT > __ > please don't Cc me, but send to list -- I'm subscribed > -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.linbit.com/pipermail/drbd-user/attachments/20160707/93d4d277/attachment.htm>