I've found it does give priority, it is just some applications try to be smart and only look for free memory, i believe Oracle dbms is a big culprit of this, and get the same issues on red hat with disk cache.
Cheers, Leigh Maddock Unix Systems Administrator On May 10, 2012 9:36 AM, <chris.unix.d...@gmail.com> wrote: > ** > Yeah, I had nobbled zfs in the past, but those changes were lost when I > could upgrade from opensolaris to solaris 11 and had to do a fresh install. > > I have to admit, I'm surprised that higher priority is given to fs caching > over the priority of an application working correctly. I wasn't expecting > zfs to stop a vm being started when clearly a few seconds earlier it had > run fine. > > > Cheers, > Chris > Sent via BlackBerry® from Telstra > ------------------------------ > *From: * Leigh Maddock <lmaddoc...@gmail.com> > *Date: *Thu, 10 May 2012 09:31:01 +1000 > *To: *Chris Wells<chris.unix.d...@gmail.com> > *Subject: *Re: [ug-msosug] Brains Trust: Why is VBox not freeing memory > after starting up and stopping a VM? > > Your zfs cache is using 4.66gb, if you run top now that should show about > 3.5gb free depending on what else is running. > > If you want to stop zfs using so much cache to see if it is causing the > error: > Add the following to /etc/system > set zfs:zfs_arc_max = <bytes> > The reboot. Im sure you can do it online without outage but cant find the > command, someone else may know. Otherwise might be the easiest way to clear > the arc cache and test again :). > 1gb in bytes is probably a good test. > > Cheers, > Leigh > On May 10, 2012 12:58 AM, "Chris Wells" <chris.unix.d...@gmail.com> wrote: > >> crispi@marvin:/VMs/IBM$ kstat -p zfs:0:arcstats:\size >> zfs:0:arcstats:size 5007987624 >> >> >> On Thu, May 10, 2012 at 12:30 AM, Leigh Maddock <lmaddoc...@gmail.com>wrote: >> >>> Hi Chris, >>> >>> Are you running your VDI's off zfs? It's possible the vbox disk is being >>> loaded into the zfs arc cache. >>> >>> Run the following command before and after and see if it is showing your >>> missing memory: >>> # kstat -p zfs:0:arcstats:\size >>> >>> You can limit the amount of cache ZFS is allowed to use if this is the >>> case. >>> >>> I have seen numerous times where applications try to be too smart for >>> their own good by checking for free memory as opposed to just asking for it >>> and letting the OS release the cache. >>> >>> Cheers, >>> Leigh Maddock >>> Unix Systems Administrator >>> >>> On Wed, May 9, 2012 at 10:56 PM, Chris Wells >>> <chris.unix.d...@gmail.com>wrote: >>> >>>> Thanks Richard. I wouldn't mind, but the behaviour is annoying: >>>> >>>> 1) A restart of the same VM will sometimes fail >>>> 2) The VM will fail half-way through boot up (so I guess the memory >>>> isn't preallocated). >>>> >>>> This kind of indeterminate behaviour is annoying for what should be >>>> mature products by now. >>>> >>>> Chris >>>> >>>> >>>> >>>> On Wed, May 9, 2012 at 10:35 PM, Richard Smith < >>>> richard.r.sm...@oracle.com> wrote: >>>> >>>>> My guess is that the memory is lurking inside kmem caches. Since the >>>>> system >>>>> isn't under memory pressure, there's nothing to trigger a reap of them. >>>>> You can get a better idea where the memory has gone from the mdb dcmds >>>>> below. There are a lot of kmem caches though, and I expect only a few >>>>> of them account for most of the "missing" memory. >>>>> >>>>> ::memstat >>>>> ::kmastat -m >>>>> ::kmem_cache >>>>> ::kmem_slabs >>>>> >>>>> >>>>> -- >>>>> ==============================**==============================** >>>>> ================ >>>>> ,-_|\ Richard Smith PAE >>>>> / \ Oracle Phone : +61 3 8616 3300 >>>>> richard.r.sm...@oracle.com Direct : +61 404 815 885 >>>>> \_,-._/ 417 St Kilda Road Fax : +61 3 8616 4500 >>>>> v Melbourne Vic 3004 Australia >>>>> ==============================**==============================** >>>>> =============== >>>>> >>>> >>>> >>>> >>>> -- >>>> Regards, >>>> >>>> Chris >>>> >>>> _______________________________________________ >>>> ug-msosug mailing list >>>> ug-msosug@opensolaris.org >>>> http://mail.opensolaris.org/mailman/listinfo/ug-msosug >>>> >>>> >>> >> >> >> -- >> Regards, >> >> Chris >> >
_______________________________________________ ug-msosug mailing list ug-msosug@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/ug-msosug
