Sent via BlackBerry by AT&T -----Original Message----- From: Wendy Cheng <s.wendy.cheng@xxxxxxxxx> Date: Thu, 08 May 2008 09:28:22 To:linux clustering <linux-cluster@xxxxxxxxxx> Subject: Re: GFS lock cache or bug? Ja S wrote: > Hi, All: > I have an old write-up about GFS lock cache issues. Shareroot people had pulled it into their web site: http://open-sharedroot.org/Members/marc/blog/blog-on-gfs/glock-trimming-patch/?searchterm=gfs It should explain some of your confusions. The tunables described in that write-up are formally included into RHEL 5.1 and RHEL 4.6 right now (so no need to ask for private patches). There is a long story about GFS(1)'s "ls -la" problem that one time I did plan to do something about it. Unfortunately I'm having a new job now so the better bet is probably going for GFS2. Will pass some thoughts about GFS1's "ls -la" when I have some spare time next week. -- Wendy > I used to 'ls -la' a subdirecotry, which contains more > than 30,000 small files, on a SAN storage long time > ago just once from Node 5, which sits in the cluster > but does nothing. In other words, Node 5 is an idel > node. > > Now when I looked at /proc/cluster/dlm_locks on the > node, I realised that there are many PR locks and the > number of PR clocks is pretty much the same as the > number of files in the subdirectory I used to list. > > Then I randomly picked up some lock resources and > converted the second part (hex number) of the name of > the lock resources to decimal numbers, which are > simply the inode numbers. Then I searched the > subdirectory and confirmed that these inode numbers > match the files in the subdirectory. > > > Now, my questions are: > > 1) how can I find out which unix command requires what > kind of locks? Does the ls command really need PR > lock? > > 2) how long GFS caches the locks? > > 3) whether we can configure the caching period? > > 4) if GFS should not cache the lock for so many days, > then does it mean this is a bug? > > 5) Is that a way to find out which process requires a > particular lock? Below is a typical record in > dlm_locks on Node 5. Is any piece of information > useful for identifing the process? > > Resource d95d2ccc (parent 00000000). Name (len=24) " > 5 cb5d35" > Local Copy, Master is node 1 > Granted Queue > 137203da PR Master: 73980279 > Conversion Queue > Waiting Queue > > > 6) If I am sure that no processes or applications are > accessing the subdirectory, then how I can force GFS > release these PR locks so that DLM can release the > corresponding lock resources as well. > > > Thank you very much for reading the questions and look > forward to hearing from you. > > Jas > > > ____________________________________________________________________________________ > Be a better friend, newshound, and > know-it-all with Yahoo! Mobile. Try it now. http://mobile.yahoo.com/;_ylt=Ahu06i62sR8HDtDypao8Wcj9tAcJ > > -- > Linux-cluster mailing list > Linux-cluster@xxxxxxxxxx > https://www.redhat.com/mailman/listinfo/linux-cluster > -- Linux-cluster mailing list Linux-cluster@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/linux-cluster -- Linux-cluster mailing list Linux-cluster@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/linux-cluster
