[Lustre-discuss] need help

[Kevin Van Maren]

Ashok nulguda wrote:
> Dear All,
>
> How to forcefully shutdown the luster service from client and OST and 
> MDS server when IO are opening.
>
For the servers, you can just umount them.  There will not be any "file 
system" corruption, but files will not have the latest data -- the cache 
on the clients will not be written to disk (unless recovery happens -- 
restart the servers without having rebooted the clients).  In an 
emergency, this is normally all you have time to do before shutting down 
the system.

To unmount clients, not only can there not be any IO, you also need to 
first kill every process that has an open file on Lustre.  "lsof" can be 
useful here if you don't want to do a full shutdown, but in many 
environments killing non-system processes is enough.

Normally you'd want to shutdown all the clients, and then the servers.

Kevin