<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0//EN" "http://www.w3.org/TR/REC-html40/strict.dtd"><html><head><meta name="qrichtext" content="1" /><style type="text/css">p, li { white-space: pre-wrap; }</style></head><body style=" font-family:'DejaVu Sans'; font-size:10pt; font-weight:400; font-style:normal;">On Donnerstag 24 September 2009 12:58:35 Brian J. Murrell wrote:<br>
<p style="-qt-paragraph-type:empty; margin-top:0px; margin-bottom:0px; margin-left:0px; margin-right:0px; -qt-block-indent:0; text-indent:0px; -qt-user-state:0;"><br></p>Get device list on MDS:<br>
lctl dl<br>
<p style="-qt-paragraph-type:empty; margin-top:0px; margin-bottom:0px; margin-left:0px; margin-right:0px; -qt-block-indent:0; text-indent:0px; -qt-user-state:0;"><br></p>Disabling write only. Read on clients possible.:<br>
lctl set_param osc.lustre-OST000d-osc.active=0<br>
<p style="-qt-paragraph-type:empty; margin-top:0px; margin-bottom:0px; margin-left:0px; margin-right:0px; -qt-block-indent:0; text-indent:0px; -qt-user-state:0;"><br></p>Disable read/write (disabling device permanently):<br>
lctl --device 18 conf_param lustre-OST000d.osc.active=0<br>
(18 and OST000d) has to be replaced by your stuff of course)<br>
<p style="-qt-paragraph-type:empty; margin-top:0px; margin-bottom:0px; margin-left:0px; margin-right:0px; -qt-block-indent:0; text-indent:0px; -qt-user-state:0;"><br></p>Watchout:<br>
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.<br>
https://bugzilla.lustre.org/show_bug.cgi?id=18329<br>
<p style="-qt-paragraph-type:empty; margin-top:0px; margin-bottom:0px; margin-left:0px; margin-right:0px; -qt-block-indent:0; text-indent:0px; -qt-user-state:0;"><br></p>All commands on MDS.<br>
Thanks to Andreas Dilger some time ago who pointed that out.<br>
<p style="-qt-paragraph-type:empty; margin-top:0px; margin-bottom:0px; margin-left:0px; margin-right:0px; -qt-block-indent:0; text-indent:0px; -qt-user-state:0;"><br></p>Regards<br>
Heiko<br>
<p style="-qt-paragraph-type:empty; margin-top:0px; margin-bottom:0px; margin-left:0px; margin-right:0px; -qt-block-indent:0; text-indent:0px; -qt-user-state:0;"><br></p>> On Thu, 2009-09-24 at 11:31 +0200, Frank Heckes wrote:<br>
> > Hi all,<br>
> <br>
> Hi,<br>
> <br>
> > sorry if this has been answered before, but I could find only one<br>
> > un-answered question concerning this topic in the archive.<br>
> <br>
> Hrm. Strange, as I believe this has been answered in the archive many,<br>
> many times. I believe the answer to this is in the manual too.<br>
> <br>
> > If I like to deactivate write operation for an OST temporary, but allow<br>
> > clients to read still data from the OST, disabling the OST on the MDS<br>
> > will do the job as described in the admin guide.<br>
> <br>
> Not quite. Disabling on the MDS only disables "new allocation", not<br>
> write. That means that new objects won't be allocated to files from the<br>
> deactivated OST. Writes to existing objects will still be allowed.<br>
> <br>
> > In case an OST was lost and clients shouldn't contact the OST anymore<br>
> > (if OST is damaged irreversible) even for read operation, could I<br>
> > execute the 'lcl --device <id> deactivate' command also on the clients?<br>
> <br>
> Hrm. I usually fiddle with the proc file directly on this, but suffice<br>
> it to say that whatever operation you are using on the MDS to deactivate<br>
> an OST can be used on the client to return EIOs when a given OST is<br>
> accessed.<br>
> <br>
> > Or is this action superfluous since the client will receive EIO's<br>
> > anyway?<br>
> <br>
> No. The client will only receive EIOs if that client has deactivated<br>
> the OST.<br>
> <br>
> > Many thanks in advance.<br>
> <br>
> NP.<br>
> <br>
> b.<br>
> <br>
> <br>
<p style="-qt-paragraph-type:empty; margin-top:0px; margin-bottom:0px; margin-left:0px; margin-right:0px; -qt-block-indent:0; text-indent:0px; -qt-user-state:0;"><br></p>-- <br>
-----------------------------------------------------------------------<br>
!!! NEUE TELEPHONNUMMER !!!<br>
!!! NEW PHONE NUMBER !!!<br>
<p style="-qt-paragraph-type:empty; margin-top:0px; margin-bottom:0px; margin-left:0px; margin-right:0px; -qt-block-indent:0; text-indent:0px; -qt-user-state:0;"><br></p>Dipl.-Ing. Heiko Schröter<br>
Institute of Environmental Physics (IUP) phone: ++49-(0)421-218-62092<br>
Institute of Remote Sensing (IFE) fax: ++49-(0)421-218-4555<br>
University of Bremen (FB1)<br>
P.O. Box 330440 email: schroete@iup.physik.uni-bremen.de<br>
Otto-Hahn-Allee 1 <br>
28359 Bremen <br>
Germany<br>
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