Date: Thu, 31 Jan 2002 11:42:27 +0500 From: Sergey Gershtein <sg@ur.ru> To: Peter Jeremy <peter.jeremy@alcatel.com.au> Cc: freebsd-stable@FreeBSD.ORG Subject: Re[2]: Strange lock-ups during backup over nfs after adding 1024M RAM Message-ID: <381384473377.20020131114227@ur.ru> In-Reply-To: <20020131111153.Y72285@gsmx07.alcatel.com.au> References: <20020126204941.H17540-100000@resnet.uoregon.edu> <1931130530386.20020128130947@ur.ru> <20020130073449.B78919@gsmx07.alcatel.com.au> <791310002584.20020130150111@ur.ru> <20020131111153.Y72285@gsmx07.alcatel.com.au>
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On Thursday, January 31, 2002 Peter Jeremy wrote: PJ> It looks like you've run out of kernel memory. At a quick guess, one PJ> of the nfsd processes is trying to open a file and can't allocate PJ> space for another inode whilst holding locks on other inodes. The PJ> lockup is either due to the lack of KVM, or the inode locks are PJ> migrating up towards root and gathering more processes under their PJ> clutches until nothing can run. PJ> If you monitor the memory usage with "vmstat -m", you should be PJ> able to see the free memory drop to zero, possibly all eaten by PJ> the "FFS node". I've set up a cron job to monitor vmstat -m every 5 minutes so I can see what happens just before the next lock-up. >>By the way, the file system that is being backuped has a lot (more >>than 1,000,000) of small files (less than 1Kb each). PJ> That triggers a faint memory about a problem with doing this, but PJ> I thought it was now fixed. How old are your sources? RELENG_4_4 cvsuped a week ago (Jan 24th). For some reason we don't cvsup 4.5 until it becomes RELEASE. PJ> Increasing the amount of physical RAM increases the amount of KVM PJ> required to manage the RAM, reducing the amount of memory available PJ> for other things. I didn't keep your original posting and I can't PJ> remember what MAXUSERS is set to - from memory it is either 128 PJ> (which seems too small) or 1024 (which seems too large). Try altering PJ> maxusers to 400-500 and see if that helps. The initial value of MAXUSERS was 512, I tried lowering it to 128 according to Doug White's advice, but it did not help. Another server with the same hardware (which does not lock up) has MAXUSERS 1024, but it also does not have over 1,000,000 small files to backup. PJ> If you still have problems, I think you'll need one of the FS gurus. My hope was to find gurus on this list, I have no clue where else I can search for them. :( Nevertheless, thank you for your help! Regards, Sergey Gershtein To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-stable" in the body of the message
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