System Slow Down, lots of Pageouts

Discussion in 'Parallels Desktop 3.0 for Mac Public Beta' started by rwintheiser@gmail.com, Aug 28, 2007.

  1. MBP 2.33 Ghz Core 2 Duo
    OS X 10.4.10
    2 GB Ram
    Parallels 5120 (but problem started earlier)
    XP SP2, no Swapfile
    Sharing turned OFF
    768 mb memory for Parallels

    When I start the windows OS my entire OS X system slows to a crawl and is largely unusable. Even cmd-tab does not work. Pageouts go through the roof, IMHO, jumping by nearly 100k until XP stabilizes. I have really done nothing to this except use it. I have another VM, win2000 that just screams along with ZERO pageouts.

    I have tried to do all the "tricks" and optimization that is listed here on the forum. Does anyone have any ideas on what to do here?
     
  2. spectre

    spectre Parallels Team

    Messages:
    270
    Please make sure that Reserved Memory Limit under Parallels menubar - Preferences - Memory doesn't exceed the amount of memory allocated to all or single VM(s) running. Try setting the Reserved Memory Limit to Manual and increasing it to maximum.
     
  3. Olivier

    Olivier Kilo Poster

    Messages:
    610
    What would be the right recommend way to set that after all? Automatic or Manual? When set to Automatic, what is the policy applied (how is the amount of used memory computed)?
    Thanks,
     
  4. slimemold

    slimemold

    Messages:
    110
    I've often wondered about this as well. I'm getting an unusual amount of page-outs.

    I have 1024MB allocated to my WinXP VM. That's the only VM I run. I can't set the Preferences - Memory to anything <= 1024, or Parallels refuses to start the virtual machine. What's the deal?
     
  5. Well it has help the system, it is not quite so sluggish but I am still getting a bunch of pageouts.. (nearly 300k from first launch this morning). Sometimes the system will just bog down still. BTW, I manually maxed out what you told me but did not check off the virtual memory pre-allocation. Any more ideas?
     
  6. STim

    STim Super Moderator

    Messages:
    942
    What is your way to detect pageouts count?

    What are the Mac applications that usually run when you start Parallels Desktop VM? Have you tried starting Parallels Desktop when no Mac apps are running? If so, have you noticed any positive changes?

    Can you please try decreasing your VM's guest RAM to 512MB and even to 368MB for testing purposes? Will this also improve pagouts count and general Mac health?

    Thank you in advance for your answers, they will help us investigate the issue.
     
  7. slimemold

    slimemold

    Messages:
    110
    Can someone please address the contradiction I pointed out in my previous post?

    I've always suspected that there is OSX-level page caching as well as VM-level page caching because of the way I/Os are being done with a virtual HD. I didn't see this massive amount of page-out when I was using a bootcamped disk.

    I use istatpro to measure memory usage, by the way.

    The eating up of memory happens to me after doing a devstudio build in the XP VM (which is very file I/O intensive). After that, I've perpetually got very little free space, while my inactive space is huge, and there is a steady trickle of page outs.
     
  8. - I am using Activity Monitor and top -u, never had pageouts before.

    - Safari, Mail, Skype, Adium, usually Word and Excel,...

    - no I will explore this and post later.

    - Will test this too.

     
  9. I have tested most of what you asked. With the Memory Limit maxed, moving to 512 reduces dramatically the pageouts to less than 10. At 368 they go away. System reponse seems good. If I drop the Memory Limit to 1024, up system memory to 512, pageouts rise again, significantly. It looks like when the Free Memory dwindles to almost nothing, Parallels moves into pageouts.... In the situation, max memory limit, and 768mb, the free memory is literally nonexistant. Please council me on what you still want me to look into.

    BTW, with Max Memory Limit, it really chews up over have the RAM. This is not a good situation for me, I believe that Parallels should be able to manage this, more or less, dynamically.
     
  10. slimemold

    slimemold

    Messages:
    110
    Yes, I'd really like to know what the deal is with Parallels chewing through memory. I've noted many times that this does not seem to happen when booting with a bootcamp partition, so I think it has something to do with the disk emulation of using a virtual disk, and brought up the possibility of the redundant caching. Can someone from staff PLEASE acknowledge this possibility or shut me up so that I can get some sleep tonight? :p
     
  11. forgie

    forgie

    Messages:
    54
    I've noticed that my VM has really slowed down after increasing its RAM to 800MB. It used to be on 256MB, and it flew along with that, but recently I've been doing 3D CAD work in PD, so I upped it to 800MB. Now when I resume from a suspended VM, PD takes AGES to become responsive, and I'm sure that PD is hammering my HDD more than it used to on 256MB. I've got no idea if this issue has always been there, since I've only increased my RAM allocation while running the recent round of betas.
     
  12. slimemold

    slimemold

    Messages:
    110
    Okay, now I'm getting rather irritated. I've mentioned the possibility of redundant filesystem-level caching several times now within the span of a month or so, and have been completely ignored by staff (or by everyone else for that matter :p). I wonder if my guess is actually correct, and they're too embarrassed to talk about it?
     
  13. Just an additional note, after launch of Parallels, it seems to grab ALL available memory, leaving pushing the Wired way up, and making the free go down to around 20mb... When this happens, the system just crawls, then page outs become very frequent. I rebooted this morning, cleared out the page counter and now have 233325 in and 277078 out. This was with Max Memory Limit and 512mb of RAM. Before launch I had 242mb Wired, 833 active, 510 inactive, and 460 free for my memory....
     
  14. Safari?

    I intalled the new BETA and had the same issues. I then took a peak at memory usage, again. Kernal 1.37, Parallel 1.13 and Safari 1.1. Closed Safari and the system worked fine. Restarted Safari, memory down to 373mb... I still do not know why we need to have so much memory dedicated to Parallels...
     
  15. non-troppo

    non-troppo

    Messages:
    51
    Because it is a virtual machine and your guest OS has to wire the RAM it uses? The issue is not that Parallels uses the wired RAM you've asked for. But whether anything else is going on on top of that. I note some substantial slowdowns with 5144 over time, suggestive of a leak somewhere -- that should be fixed but remember this is a beta. Fusion also wires lots of RAM (and also seems to leak over time for some users).
     
  16. non-troppo, that is all fine and good but....
    1. This did not happen in 2.x and I believe the first round of 3.x
    2. Beta, yes that is why I am posting this here, so the product can improve.
    3. I always have many programs running, and expect that they manage automatically their memory. This is not the case in this current release. As in point 1, no problems until 3.x something.
    4. I am posting as much information as is possible so the developers can see what may be the culprit here. Thus I am not really complaining, if I was I'd revert to an earlier build.
     

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