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On Wed, 2003-06-04 at 23:12, niblettda@gru.com wrote: > Thanks Franco, > > One question I have after reading the list is more of > real world performance. I've read the info about how it > compares to ext2 and such, but I really want to know how > that translates into a real application. > > If I've got a users reading email via IMAP, are we talking > enough of a performance hit that it will take noticeably > longer to pull each message up, or are we on the order of > a 1/2s longer? > > Certainly speed is required if you are a huge data store > of file shares, but in an application like SMTP writes, > POP/IMAP reads, etc will this performance hit be so big > that I need to worry? We are currently running about 7TB over 1Gbit Fibre Channel with 8 nodes. For large file access GFS performs pretty well, listing directories and initial access to files can be a little hesitant. I wouldn't imagine you'd notice any delays with pop/smtp access unless you were being hit by a huge number of simultaneous users. > > Also, you mention multiple lock servers v. pools. I guess > I didn't understand as well as I thought I did. I thought > pools were what were used to lock files? > > Assuming they are not, then I guess I would have to implement > the heartbeat and multiple lock servers, right? Correct. We have not felt this necessary in our environment. Our lock server is a dedicated machine with lots of grunt, and so far we have not had a failure (touch wood, fingers crossed) - it runs 14 memexp daemons. > > What happens if you only have one lock server and it dies. > I know the FS can't be accessed, just wondering how "graceful" > this death would be. Are there file system corruption > possibilities? The whole cluster hangs and requires a full reboot with the revived lock server. You'd be unlucky to loose any data, GFS uses journals which get replayed when the first node mounts the filesystem. > > Thanks > > -- > David A. Niblett | email: niblettda@gru.net > Network Administrator | Phone: (352) 334-3400 > Gainesville Regional Utilities | Web: http://www.gru.net/ > > > > -----Original Message----- > From: Franco Broi [mailto:franco@robres.com.au] > Sent: Tuesday, June 03, 2003 10:48 PM > To: opengfs-users@lists.sourceforge.net > Subject: Re: [ogfs-users]Suitability of ogfs for my HA situation > > > On Tue, 2003-06-03 at 23:14, niblettda@gru.com wrote: > > I've been researching GFS for a few years now, back when it was > > sponsored by Sistina. I think I'm finally at a point that I could use > > it, and I wanted to see if it was at a point that it would be useful > > for me. > > > > Admittedly I don't understand a lot of the low level details of how > > the FS works. So I don't really follow most of the bug details. > > > > What I would like to do is have 4 nodes all serving SMTP, POP, FTP, > > etc (standard ISP services) that read/write to a central data store, > > Compaq SAN MSA1000 device. Basically, all user data will be stored > > there, and I'll load balance across the 4 machines. My main questions > > are: > > > > Will the performance be good/bad/ugly enough for a moderate number > > (say 25-50 simultaneous) reads/writes from each node? > > > > I read and followed most of the HOWTO on the no-pool, since > > I don't want a single lock server. Is that feature ready > > for a production environment? > > I don't think having pools has anything to do with having multiple lock > servers. Certainly the no pool code works, although I can only vouche for it > working over a 2 week period, my test setup has since been dismantled. > > > > > Should a node die, with open files, will ogfs eventually release the > > locks so that other nodes can access the file? How long before the > > locks get released? > > Yes. The length of time depends on the timeout you set in the configuration > file. As soon as the failed node has been stomith'd, the other nodes can > replay the failed node's journal(s) and can access the locked files. > > > > > I'm also investigating purchasing GFS from Sistina, but if ogfs will > > accomplish the job, then why not. > > We have a Sistina GFS cluster (8 nodes) running a rather old version, in my > brief test, ogfs seemed at least as good - but I haven't tried the latest's > release from Sistina which promised much improved performance. > > > > > Thanks all. > > > > -- > > David A. Niblett | email: niblettda@gru.net > > Network Administrator | Phone: (352) 334-3400 > > Gainesville Regional Utilities | Web: http://www.gru.net/ > > > > > > > > ------------------------------------------------------- > > This SF.net email is sponsored by: eBay > > Get office equipment for less on eBay! > > http://adfarm.mediaplex.com/ad/ck/711-11697-6916-5 > > _______________________________________________ > > Opengfs-users mailing list Opengfs-users@lists.sourceforge.net > > https://lists.sourceforge.net/lists/listinfo/opengfs-users > > > > > > ------------------------------------------------------- > This SF.net email is sponsored by: Etnus, makers of TotalView, The best > thread debugger on the planet. Designed with thread debugging features > you've never dreamed of, try TotalView 6 free at www.etnus.com. > _______________________________________________ > Opengfs-users mailing list > Opengfs-users@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/opengfs-users > > > ------------------------------------------------------- > This SF.net email is sponsored by: Etnus, makers of TotalView, The best > thread debugger on the planet. Designed with thread debugging features > you've never dreamed of, try TotalView 6 free at www.etnus.com. > _______________________________________________ > Opengfs-users mailing list > Opengfs-users@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/opengfs-users ------------------------------------------------------- This SF.net email is sponsored by: Etnus, makers of TotalView, The best thread debugger on the planet. 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