On Oct 21, 2003 13:47 -0400, Nicholas Henke wrote:> Ok, say I have setup lustre to use a 40GB partition somewhere, and I > have used all of that space. > > 1) Can I add another OST on an existing machine ? If so, is there > anything special I need to do ?If you have used a LOV then yes you can do this, otherwise unfortunately you cannot change from a non-LOV setup to one which has a LOV. If yes, then just add the new OST to the config AFTER the existing OST(s).> 2) Can I add another host with additional OSTs? Do I need another > MDSDEV?Yes. No - consider an MDSDEV as "the filesystem" so unless you want to have multiple filesystems you do not need a separate MDSDEV. That said, the current b_devel needs just a bit more work in order to handle "full" vs. "empty" OSTs. That code lives in b_qos and I believe it works right now but I haven''t tested it myself. You could also use lstripe and cp to migrate objects to the new OST. Cheers, Andreas -- Andreas Dilger http://sourceforge.net/projects/ext2resize/ http://www-mddsp.enel.ucalgary.ca/People/adilger/
On Tue, 2003-10-21 at 15:08, Andreas Dilger wrote:> On Oct 21, 2003 13:47 -0400, Nicholas Henke wrote: > > Ok, say I have setup lustre to use a 40GB partition somewhere, and I > > have used all of that space. > > > > 1) Can I add another OST on an existing machine ? If so, is there > > anything special I need to do ? > > If you have used a LOV then yes you can do this, otherwise unfortunately > you cannot change from a non-LOV setup to one which has a LOV. If yes, > then just add the new OST to the config AFTER the existing OST(s).Great, I am using LOV''s on all of the setups here. I was unaware there was a way to eliminate the LOV.> > > 2) Can I add another host with additional OSTs? Do I need another > > MDSDEV? > > Yes. No - consider an MDSDEV as "the filesystem" so unless you want > to have multiple filesystems you do not need a separate MDSDEV.Ah, ok that makes more sense.> That said, the current b_devel needs just a bit more work in order to handle > "full" vs. "empty" OSTs. That code lives in b_qos and I believe it > works right now but I haven''t tested it myself. You could also use > lstripe and cp to migrate objects to the new OST.in b_qos, what would the behavior be when an empty OST is added? Will it automatically ''rebalance'', or just have the ability to use that space, but in a non-striped fashion? Nic -- Nicholas Henke Penguin Herder & Linux Cluster System Programmer Liniac Project - Univ. of Pennsylvania
On Oct 21, 2003 15:20 -0400, Nicholas Henke wrote:> On Tue, 2003-10-21 at 15:08, Andreas Dilger wrote: > > That said, the current b_devel needs just a bit more work in order to > > handle "full" vs. "empty" OSTs. That code lives in b_qos and I believe > > it works right now but I haven''t tested it myself. You could also use > > lstripe and cp to migrate objects to the new OST. > > In b_qos, what would the behavior be when an empty OST is added? Will it > automatically ''rebalance'', or just have the ability to use that space, > but in a non-striped fashion?Currently it will just prefer to use space on the least-full OST(s) first. It will still try to stripe over the default number of OSTs however. If you are running b_qos, it should be possible to "migrate" your data to the new OST by doing something like "mv <dir> /tmp; mv /tmp/<dir> <dir>". In the future there will be object migration between OSTs, but that is not implemented yet. Cheers, Andreas -- Andreas Dilger http://sourceforge.net/projects/ext2resize/ http://www-mddsp.enel.ucalgary.ca/People/adilger/
Ok, say I have setup lustre to use a 40GB partition somewhere, and I have used all of that space. 1) Can I add another OST on an existing machine ? If so, is there anything special I need to do ? 2) Can I add another host with additional OSTs? Do I need another MDSDEV? Nic -- Nicholas Henke Penguin Herder & Linux Cluster System Programmer Liniac Project - Univ. of Pennsylvania