Date: Thu, 31 Jan 2002 08:39:55 -0500 From: talist@vif.com To: stable@freebsd.org Subject: Re: Strange lock-ups during backup over nfs after adding 1024M RAM Message-ID: <1012484395.3c59492bedd93@email.vif.com> In-Reply-To: <381384473377.20020131114227@ur.ru> 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> <381384473377.20020131114227@ur.ru>
next in thread | previous in thread | raw e-mail | index | archive | help
I am also encountring strange lock-ups with high traffic situation on DUMMYNET. I have managed to avoid those lock-ups by adjusting the granularity of the kernel options HZ=1000 # originally 100 Quoting Sergey Gershtein <sg@ur.ru>: > 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 > To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-stable" in the body of the message
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?1012484395.3c59492bedd93>