[Lustre-discuss] umounting server with or without failover

[Wojciech Turek]

Please find below a snippets from Lustre-1.8 manual regarding server
umount with our without failover (-f option). As you can see 4.3.4
contardics 4.5.1 and 4.5.2. Has something changed or is it a manual
BUG?


4.3.4  Unmounting a Server
To stop a Lustre server, use the umount <mount point> command.
For example, to stop ost0 on mount point /mnt/test, run:

$ umount /mnt/test
Gracefully stopping a server with the umount command preserves the state of the
connected clients. The next time the server is started, it waits for
clients to reconnect,
and then goes through the recovery procedure.

If the force (-f) flag is used, then the server evicts all clients and
stops WITHOUT
recovery. Upon restart, the server does not wait for recovery. Any currently
connected clients receive I/O errors until they reconnect.

4.5.1 Unmounting a Server (without Failover)
To stop a server (MDS or OSS) without failover, run:
umount <mds|oss mountpoint>

This stops the server unconditionally, and cleans up client
connections and export
information. When the server restarts, the clients create a new
connection to it.

4.5.2 Unmounting a Server (with Failover)
To stop a server (MDS or OSS) with failover, run:
umount -f <MDS|OSS mount point>

This stops the server and preserves client export information. When the server
restarts, the clients reconnect and resume in-progress transactions.


-- 
--
Wojciech Turek

Assistant System Manager

High Performance Computing Service
University of Cambridge