mbuf leakage with nfs/zfs?

[Jeremy Chadwick]

On Sat, Feb 27, 2010 at 08:21:05PM +0100, Gerrit Kühn wrote:
> On Sat, 27 Feb 2010 15:15:52 +0100 Willem Jan Withagen <wjw at digiware.nl>
> wrote about Re: mbuf leakage with nfs/zfs?:
> 
> WJW> > 81492/2613/84105 mbufs in use (current/cache/total)
> WJW> > 80467/2235/82702/128000 mbuf clusters in use
> WJW> > (current/cache/total/max) 80458/822 mbuf+clusters out of packet
> WJW> > secondary zone in use (current/cache)
> 
> WJW> Over the night I only had rsync and FreeBSD nfs traffic.
> WJW> 
> WJW> 45337/2828/48165 mbufs in use (current/cache/total)
> WJW> 44708/1902/46610/262144 mbuf clusters in use (current/cache/total/max)
> WJW> 44040/888 mbuf+clusters out of packet secondary zone in use
> WJW> (current/cache)
> 
> After about 24h I now have
> 
> 128320/2630/130950 mbufs in use (current/cache/total)
> 127294/1200/128494/512000 mbuf clusters in use (current/cache/total/max)
> 127294/834 mbuf+clusters out of packet secondary zone in use (current/cache)

Follow-up regarding my server statistics shown here:

http://lists.freebsd.org/pipermail/freebsd-stable/2010-February/055458.html

I just pulled the statistics on the same servers for comparison (then
vs. now).

RELENG_7 amd64 2010/01/09 -- primary HTTP, pri DNS, SSH server + ZFS

	515/1930/2445 mbufs in use (current/cache/total)
	512/540/1052/25600 mbuf clusters in use (current/cache/total/max)
	1152K/6394K/7547K bytes allocated to network (current/cache/total)

RELENG_7 amd64 2010/01/11 -- secondary DNS, MySQL, dev box + ZFS

	514/1151/1665 mbufs in use (current/cache/total)
	512/504/1016/25600 mbuf clusters in use (current/cache/total/max)
	1152K/2203K/3356K bytes allocated to network (current/cache/total)

RELENG_7 i386 2008/04/19 -- secondary HTTP, SSH server, heavy memory I/O

	515/820/1335 mbufs in use (current/cache/total)
	513/631/1144/25600 mbuf clusters in use (current/cache/total/max)
	1154K/2615K/3769K bytes allocated to network (current/cache/total)

RELENG_8 amd64 2010/02/02 -- central backups + NFS+ZFS-based filer

	1572/3423/4995 mbufs in use (current/cache/total)
	1539/3089/4628/25600 mbuf clusters in use (current/cache/total/max)
	3471K/7449K/10920K bytes allocated to network (current/cache/total)

So, not much difference.

I should point out that the NFS+ZFS-based filer doesn't actually do its
backups using NFS; it uses rsnapshot (rsync) over SSH.  There is intense
network I/O during backup time though, depending on how much data there
is to back up.  The NFS mounts (on the clients) are only used to provide
a way for people to get access to their nightly backups in a convenient
way; it isn't used very heavily.

I can do something NFS-intensive on any of the above clients if people
want me to kind of testing.  Possibly an rsync with a source of the NFS
mount and a destination of the local disk would be a good test?  Let me
know if anyone's interested in me testing that.

-- 
| Jeremy Chadwick                                   jdc at parodius.com |
| Parodius Networking                       http://www.parodius.com/ |
| UNIX Systems Administrator                  Mountain View, CA, USA |
| Making life hard for others since 1977.              PGP: 4BD6C0CB |