[Lustre-discuss] Proper shutdown sans clients

[K. Scott Rowe]

The problem is many of our clients are workstations on people's desks
as well as servers and clusters.  I don't have a good list of all the
Lustre clients so I don't know all the clients to unmount.  I've
thought about making a script to parse lshowmount and unmount clients
that way but haven't had the time.  I was hoping that ignoring the
clients would be acceptable and just let them recover once Lustre is
back up.

So, I guess it is a question of risk.  If the consensus is that
shutting down the clients first is very important to prevent data loss
and/or corruption then I will get a script working to do that.  But,
if the risk is minimal given a recommended way to shutdown Lustre
without dealing with the clients, I would be interested in that.


On Oct 22 15:06, Lee, Brett wrote:
}Scott,
}
}What is preventing the clients from being shut down?  Unable to unmount the file system?  If that is the case, please try "umount -f" instead of umount.  This will result in an unclean unmount, but the client *will* be able to unmount Lustre.  If other, please advise.
}
}Regarding the order of shutdown, I've been advocating:
}
}Clients
}MDT
}OSTs
}
}As the MDS is a client of the OSTs (the MDS runs an OSC for each OST).
}
}However, using this method has seemingly triggered the recovery process on targets when bringing up the file system.
}
}I understand that in version 2.4, OSSs will need to communicate with the MDSs, seemingly creating a two way dependency (possibly my confusion on the matter, but clarification here is requested ).  However, as you are using 1.8.7, this latter point should not cause you any problems.
}
}--
}Brett Lee
}Sr. Systems Engineer
}Intel High Performance Data Division
}
}
}> -----Original Message-----
}> From: lustre-discuss-bounces at lists.lustre.org [mailto:lustre-discuss-
}> bounces at lists.lustre.org] On Behalf Of K. Scott Rowe
}> Sent: Tuesday, October 22, 2013 8:51 AM
}> To: lustre-discuss at lists.lustre.org
}> Subject: [Lustre-discuss] Proper shutdown sans clients
}> 
}> 
}> We use Lustre 1.8.7.  Our environment has many Lustre clients spread out
}> accross several networks.  When an emergency happes, like a power outage,
}> where we need to quickly shutdown the Lustre servers we frequently are
}> unable to shutdown the clients first.  I know that the documentation
}> recommends shutting down Lustre in this order:
}> 
}>   unmount clients
}>   unmount MDT
}>   unmount OSTs
}> 
}> So my question is, what would the recommended procedure be if one cannot
}> shutdown all the clients first?  Would it just be
}> 
}>   unmount MDT
}>   unmount OSTs
}> 
}> Or is there something else that should be done because we cannot get the
}> clients shutdown first?
}> 
}> --
}> K. Scott Rowe -- Linux Grouop Lead
}> Array Operations Center, National Radio Astronomy Observatory
}> krowe at nrao.edu -- http://www.aoc.nrao.edu/~krowe/
}> 1.575.835.7000 -- 1003 Lopezville Socorro, NM 87801
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