[OmniOS-discuss] Getting detailed NFS lock information on an OmniOS NFS server

[Scott LeFevre]

> NFS logging is a perfect way to destroy performance. It is very serial
> and will not scale well.
> One important Sun customer had the misfortune of wiring it into their
> app and when they had
> their "big event" and the systems were in production, performance was
> 15% of what they 
> expected. The only solution was to disable logging, but they required
> it for their app. Needless
> to say, the app was rewritten, but they had lots of pain during the
> "big event"
>  -- richard

Thanks Richard! Good info. I guess everything has a price.
-- 
Scott LeFevre
317-696-1010 

On Tue, 2014-08-12 at 17:22 -0700, Richard Elling wrote:

> 
> 
> On Aug 12, 2014, at 4:38 PM, Scott LeFevre <slefevre at indy.rr.com>
> wrote:
> 
> 
> 
> > This may help (or may not).  I presume this will work on OmniOS as
> > it works on other Illumos variants.
> > 
> 
> 
> NFS logging is a perfect way to destroy performance. It is very serial
> and will not scale well.
> One important Sun customer had the misfortune of wiring it into their
> app and when they had
> their "big event" and the systems were in production, performance was
> 15% of what they 
> expected. The only solution was to disable logging, but they required
> it for their app. Needless
> to say, the app was rewritten, but they had lots of pain during the
> "big event"
>  -- richard
> 
> 
> 
> > 
> > You can enable logging on an nfs share by adding 'log' to the
> > sharenfs property of a zfs file system.  For example, on one of my
> > systems I have 
> > 
> > $ zfs get sharenfs pool0/media
> > NAME           PROPERTY  VALUE                           SOURCE
> > pool0/example  sharenfs  sec=sys,log,rw=@10.1.1.0/24:... local
> > 
> > 
> > After this change, svc:/network/nfs/log:default is enabled
> > automatically and a log file 'nfslog' (and other related files) can
> > be found int /var/nfs.  I don't know if this records the locks but
> > it will at least show who/what is accessing files under an nfs
> > share.  BTW, the nfs/log service collects information for a bit
> > before it drops it into the nfslog file.
> > 
> > -- 
> > Scott LeFevre
> > 317-696-1010 
> > 
> > 
> > On Mon, 2014-08-11 at 23:49 -0400, Chris Siebenmann wrote: 
> > 
> > > Here's a question: does anyone know of a good way to get detailed NFS
> > > lock information on an OmniOS NFS server, especially information like
> > > which client has a lock on a particular file?
> > > 
> > >  'mdb -k' can be used to extract basic lock information, like the full
> > > paths of all files that have active locks against them[*], but my old
> > > Solaris mdb commands for getting more detailed NFS information don't
> > > work in the OmniOS mdb any more.
> > > 
> > >  Thanks in advance.
> > > 
> > > (I'll happily take pointers to where to look in the kernel implementation
> > > to follow struct pointers by hand with mdb's ::print and so on. From what
> > > I've found so far, I'm looking at usr/src/uts/common/klm to start with; is
> > > this right?)
> > > 
> > > 	- cks
> > > [*: via mdb's ::lminfo and '::walk lock_graph', see eg
> > >     http://utcc.utoronto.ca/~cks/space/blog/solaris/ListingFileLocks
> > > 
> > >     Solaris 10 also had ::nlm_lockson, which is still present in mdb
> > >     but doesn't seem to work any more, presumably because the actual
> > >     NFS locking implementation changed.
> > > ]
> > > _______________________________________________
> > > OmniOS-discuss mailing list
> > > OmniOS-discuss at lists.omniti.com
> > > http://lists.omniti.com/mailman/listinfo/omnios-discuss
> > 
> > _______________________________________________
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> > OmniOS-discuss at lists.omniti.com
> > http://lists.omniti.com/mailman/listinfo/omnios-discuss
> 
> 
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