Date: Mon, 9 Aug 2010 10:55:56 -0400 From: Joshua Boyd <boydjd@jbip.net> To: Ivan Voras <ivoras@freebsd.org> Cc: freebsd-stable@freebsd.org Subject: Re: 8-STABLE Slow Write Speeds on ESXI 4.0 Message-ID: <AANLkTimu2JoC6bmaBcSY3e5ovBPnwZ_s_zbRK=v8h7f6@mail.gmail.com> In-Reply-To: <AANLkTimMA6OQKt-d6ecM=GmG2ciBTis-nHNovEwvjCB-@mail.gmail.com> References: <AANLkTi=FNZ%2B=4yMPJBu%2BucGJiHqwMwQvoGcgqB%2BtPJF2@mail.gmail.com> <i3jhn0$ovp$1@dough.gmane.org> <AANLkTik%2BS2fe-sS242OXQprsEA4Oh4t6-CvBCuBCASz7@mail.gmail.com> <AANLkTimMA6OQKt-d6ecM=GmG2ciBTis-nHNovEwvjCB-@mail.gmail.com>
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On Sat, Aug 7, 2010 at 1:58 PM, Ivan Voras <ivoras@freebsd.org> wrote: > On 7 August 2010 19:03, Joshua Boyd <boydjd@jbip.net> wrote: > > On Sat, Aug 7, 2010 at 7:57 AM, Ivan Voras <ivoras@freebsd.org> wrote: > > >> It's unlikely they will help, but try: > >> > >> vfs.read_max=32 > >> > >> for read speeds (but test using the UFS file system, not as a raw device > >> like above), and: > >> > >> vfs.hirunningspace=8388608 > >> vfs.lorunningspace=4194304 > >> > >> for writes. Again, it's unlikely but I'm interested in results you > >> achieve. > >> > > > > This is interesting. Write speeds went up to 40MBish. Still slow, but 4x > > faster than before. > > [root@git ~]# dd if=/dev/zero of=/var/testfile bs=1M count=250 > > 250+0 records in > > 250+0 records out > > 262144000 bytes transferred in 6.185955 secs (42377288 bytes/sec) > > [root@git ~]# dd if=/var/testfile of=/dev/null > > 512000+0 records in > > 512000+0 records out > > 262144000 bytes transferred in 0.811397 secs (323077424 bytes/sec) > > So read speeds are up to what they should be, but write speeds are still > > significantly below what they should be. > > Well, you *could* double the size of "runningspace" tunables and try that > :) > > Basically, in tuning these two settings we are cheating: increasing > read-ahead (read_max) and write in-flight buffering (runningspace) in > order to offload as much IO to the controller (in this case vmware) as > soon as possible, so to reschedule horrible IO-caused context switches > vmware has. It will help sequential performance, but nothing can help > random IOs. > Hmm. So what you're saying is that FreeBSD doesn't properly support the ESXI controller? I'm going to try 7.3-RELEASE today, just to make sure that this isn't a regression of some kind. It seems from reading other posts that this used to work properly and satisfactorily. -- Joshua Boyd JBipNet E-mail: boydjd@jbip.net http://www.jbip.net
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