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Cactus_Jack
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Very slow, constant disc access

Running VMWare Workstation v6.5.0 Build-118166, on Windows XP SP3 host (Dell Optiplex 755). VM sessions are stored on internal 500GB SATA 3GB drive. After starting Windows XP SP3 in a VM session, system response seems very slow; ie, clicking an icon takes several seconds to respond, launched apps take unusually long to load, etc. The symptoms persist for several minutes after the XP session has started. During this time, the disc indicator in the VMWare Workstation status bar shows constant disc access.

I have defraged the session, both within Windows and using the VMware Workstation defrag utility.

Anyone have any ideas why this disc access continues for so long?

Thanks,

Jack

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ODeckard
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Yes, the snapshots count, along with all the contents of the VM's folder.

Well it looks like you have it. Using a VM of independent origin identified the problem as the VMs themselves, which all had the same problem because they inherited it from their parent, all 46 chromosomes from the same source.

So unless you want to determine what about the VMs is malfunctioning you may be ready to mark this as answered.

View solution in original post

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Scissor
Virtuoso
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Do you have Symantec AntiVirus (SAV) installed on your Guest? Some versions of SAV run a quick virus scan at boot/logon. On my Guests I can see a "DoScan" and/or "RTVSCAN" process taking up lots of CPU and Disk for several minutes after login.

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Cactus_Jack
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No Symantec installed. Do have McAfee VirusScan installed, but Task Manager does not show it running a scan. In fact, nothing stands out in Task Manager with a high CPU usage.

Anyone know of a good utility that will show what's accessing the disc drive?

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Anyone know of a good utility that will show what's accessing the disc drive?

Process Monitor does a good job of showing what is accessing the disk: http://technet.microsoft.com/en-us/sysinternals/bb896645.aspx

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ODeckard
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When you save files to the external, how fast do they move? Like, do you get a gig a minute at a bare minimum ?

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Cactus_Jack
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My VM sessions are stored on an internal drive. It's a 7200rpm SATA-II drive.

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ODeckard
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I'm sorry. I read that as external. I guess I need to read more carefully. I have several VMs on 500 gig Seagate internal SATAs, and like the speed. But just trying to divide and konquer, despite the fact that your specs indicate that you should have tremendous speed, thngs can go wrong, and the symptoms you describe are similar to what you would get with a USB1 If you copy a gig of files onto your 500 gig internal, how long does it take?

I mean, you introduced where your VMs are stored, and I considered that as an option. From the into, all your VMs are on the 500 gig SATA, and all your VMs are slow. That looks like an association. Do you have any VMs anywhere else? Do you have any fast VMs on this drive?

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Cactus_Jack
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I won't be able to test file transfer times until Monday. I did, however, run HDTach on the three drives in the system (two 160s and the 500). All benchmarked around 200MB/s.

I'm not sure that drive speed / access times is involved, however. The slowness is generally only for a few minutes after starting up. The disk access indicator is on solid for several minutes after Windows has completed loading (as evidenced by monitoring Task Manager). Once the disc access indicator goes off (normal, showing the occassional disc "hit"), the VM session performance seems normal.

Jack

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ODeckard
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Well there you have it. Your VMs are slow for only a few minutes, and your disk access indicator is on solid during that time.

Granted a lot of disk access necessary to get started, but it should not peg out for several minutes. Regardless of the speed the physical disk is capable of, the rate at which data is actually transferred during that time is low, and your VMs are slow. I didn't say you had a slow disk, only that there may be a problem with the communication channel.

Though you cannot do a speed test until Monday, how about moving one of those VMs onto one of the other disk you mentioned?

Does it peg out the dis access and run slow for several minutes on another drive?

And how large was the VM, and how long did it take to move onto the other drive ?

(that was a speed test)

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hubbardt
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How much memory does your host PC have and how much is allocated to the guest ?

Could the pagefile be doing lots of swapping ?

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Cactus_Jack
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The host machine has 4GB of memory, although Windows reports only 3.25GB (I believe this is an XP limitation?). I have 512MB allocated to the session.

The VM session files total 38.2GB. I copied these files to one of the other drives, taking about 11 minutes. Also, I've specified 30GB (pre-allocated) disc size in the VM session.

Performance of the session on the second drive is the same; can't really do anything for several minutes.

Thanks, Jack

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ODeckard
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Copying 38 GB in 11 minutes is certainly fast enough. And seing the lethargy for five minutes follow the VM to another drive means it isn't the drive.

You listed a 30 GB drive, but 38 total. Could the other 8 GB be an 8 GB pagefile drive? I use a didicated pagefile drive to speed things up,

But I keep it down around 2 GB to prevent a long startup. Loading an 8 GB pagefile will take some time, with the drive being very active until that is done. The main reason to have a huge pagefile is to have a place to store all your RAM as well as all the usual pagefile stuff when you suspend. But with a VM, the suspend is done to a file created in your VM's folder, so you don't need that much for that purpose.

Are your ohter VMs copies from the same original VM, or is there one or more that may be of independent origin ?

Often XP host machines are sometimes already overloaded before they fire up another program, which becomes the proverbial straw that broke the camel's back.

If you run Process Explorer from Wininternals.com on both the host and the guest you will see what is using what resources, plotted out on a timeline.

Also you might want to run Autoruns on each to see what programs are being automatically run every time your computer starts. Sometimes that is quite enlightening.

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Cactus_Jack
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I created a NEW VM session based on the same Windows XP SP3 source files. This new session does NOT exhibit the same lethargy (as so well put by ODeckard). Since my company uses a company-wide standard Windows XP install, this new session is running the exact same apps and configuration as the afore-mentioned, slow session. (Since these VM sessions are used for testing various new apps and updates, I do NOT vary them from what is deployed company-wide. After any testing, the session is restored to the pre-testing state, until such time as the tested software is deployed.)

The swap file size in the session was set at 1GB, twice the allocated memory size. I increased it to 2GB, with no change in the behavior.

Regarding the 38GB total files in the session folder vs. the 30GB allocated disk size; would not the 38GB worth of files include snapshots, of which there are five?

Thanks,

Jack

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ODeckard
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Yes, the snapshots count, along with all the contents of the VM's folder.

Well it looks like you have it. Using a VM of independent origin identified the problem as the VMs themselves, which all had the same problem because they inherited it from their parent, all 46 chromosomes from the same source.

So unless you want to determine what about the VMs is malfunctioning you may be ready to mark this as answered.

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Cactus_Jack
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Yeah, as much as I'd like to know what was causing the problem, It's time to move on. I'll just recreate my other sessions and be a happy VMer.

Thanks,

Jack

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Cactus_Jack
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Well, the four VM sessions I recreated and that were initially performing well are now exhibiting the same behavior. This seems to suggest that something happening during the normal course of VM session usage is causing the issue, but I have no idea what it could be. I upgraded my VMware Workstation to 6.5.1 build-126130, no change. I usually keep only the latest two snapshots.

I don't know how much more time I can spend on this, but it sure is annoying to have to wait 5 - 10 minutes after powering on a session before it responds reasonably. If anyone has any more suggestions, I'd be happy to consider 'em!

Thanks,

Jack

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Scissor
Virtuoso
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Please attach the vmware.log and .vmx files from the directory containing one of your Guests.

How much RAM is installed in your Host?

Did you ever run Process Monitor to see what was accessing your Disk? You might want to run it inside your Guest also to see what's going on in there.

Snapshots can cause slowdowns as well. VMware needs to do more internal housekeeping when dealing with multiple snapshots.

You aren't compressing the folder containing your Guest files are you?

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Cactus_Jack
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Files attached.

Host has 4GB memory

I've run Process Monitor, but honestly, it returns such a huge mountain of info I have no idea how to interpret it. Typically when I use Process Monitor it's to send the output capture to a vendor for analysis.

I typically have only 2 or 3 snapshots at any given time.

No folder compression.

Thanks,

Jack

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Virtuoso
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Are your snapshots taken while the Guest is powered off? I find snapshots taken while a Guest is powered on seem to take forever to restore... You could experiment with unchecking the VMware GUI -> Edit -> Preferences -> Priority -> "Take and restore snapshots in the background" option.

Do you typically run more than one Guest at a time?

Your Guest appears to be stored on your E: drive. Is that an external drive? Is it connected via USB, FireWire, eSATA, mapped network drive?

If possible, please configure your Host AntiVirus to exclude the directory containing your Guests from AV Real Time Scanning.

Please configure your Guest's CD-ROM to start Disconnected (I don't think this is the cause of your issue but it is a good Best Practice).

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Virtuoso
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Oops I see that you already stated your Guests are run from an internal SATA drive, so disregard that question.

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