On Donnerstag 24 September 2009 12:58:35 Brian J. Murrell wrote: Get device list on MDS: lctl dl
Disabling write only. Read on clients possible.: lctl set_param osc.lustre-OST000d-osc.active=0 Disable read/write (disabling device permanently): lctl --device 18 conf_param lustre-OST000d.osc.active=0 (18 and OST000d) has to be replaced by your stuff of course) Watchout: A bug in 'lfs' (still not fixed) will not step over an deactivated device. We do use a patched version here to get around. Version 1.6 and 1.8. https://bugzilla.lustre.org/show_bug.cgi?id=18329 All commands on MDS. Thanks to Andreas Dilger some time ago who pointed that out. Regards Heiko > On Thu, 2009-09-24 at 11:31 +0200, Frank Heckes wrote: > > Hi all, > > Hi, > > > sorry if this has been answered before, but I could find only one > > un-answered question concerning this topic in the archive. > > Hrm. Strange, as I believe this has been answered in the archive many, > many times. I believe the answer to this is in the manual too. > > > If I like to deactivate write operation for an OST temporary, but allow > > clients to read still data from the OST, disabling the OST on the MDS > > will do the job as described in the admin guide. > > Not quite. Disabling on the MDS only disables "new allocation", not > write. That means that new objects won't be allocated to files from the > deactivated OST. Writes to existing objects will still be allowed. > > > In case an OST was lost and clients shouldn't contact the OST anymore > > (if OST is damaged irreversible) even for read operation, could I > > execute the 'lcl --device <id> deactivate' command also on the clients? > > Hrm. I usually fiddle with the proc file directly on this, but suffice > it to say that whatever operation you are using on the MDS to deactivate > an OST can be used on the client to return EIOs when a given OST is > accessed. > > > Or is this action superfluous since the client will receive EIO's > > anyway? > > No. The client will only receive EIOs if that client has deactivated > the OST. > > > Many thanks in advance. > > NP. > > b. > > -- ----------------------------------------------------------------------- !!! NEUE TELEPHONNUMMER !!! !!! NEW PHONE NUMBER !!! Dipl.-Ing. Heiko Schröter Institute of Environmental Physics (IUP) phone: ++49-(0)421-218-62092 Institute of Remote Sensing (IFE) fax: ++49-(0)421-218-4555 University of Bremen (FB1) P.O. Box 330440 email: [email protected] Otto-Hahn-Allee 1 28359 Bremen Germany -----------------------------------------------------------------------
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