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May Kung
03-25-2003, 10:30 AM
This is a continuation from the thread on which OS we'd like to use in a perfect world. The discussion is about how to optimize performance by tinkering with swap file settings and setups.

I'm *guessing* that over time the OSDM/Annotator combo consumes more and more virtual memory, and this is indeed a condition which can slow the whole system down. Clearing the UNDO buffer will not return any virtual memory to the system, so this alone doesn't necessarily make the system any snappier.

That would explain why the hard reboot seems to help.

Invest some effort to configure the page file properly for your systems. Some hints on improving paging performance:

I'll mention it to the sysadmin, but since his full-time job is keeping the email and network servers running, CAD optimization is low on the list. Ditto for me, as my main job is supposed to be design work, not CAD support. We *really* need a full-time person to do such projects, or at least to have such things made a higher priority so it can get some resource. *sigh*

Create a page file partition rather than a page file on the system partition

Do you mean like an actual partition that is separate from the system partition? For example, we currently use 2 partitions, C: and D:. Perhaps we need to make E:, which would be a partition that is only used for the swap file?

Make sure that the page file is on a fast disk

Yep. All the workstations use a single 10K SCSI drive, partitioned into two. Half the page file is on C: and the other half is on D:.

Make sure that the disks in the system use DMA transfers.

Don't think is applicable for SCSI, as it's supposed to do this by default.

Set the page file to a fixed size to reduce file fragmentation.

We currently already do this.

Use a page file defragmentation tool, such as the one from http://www.sysinternals.com

Haven't tried that yet. I'll make a note to try it out when I have some free time.

Choosing the right size of page file is also important, of course.

We've been making the page files twice the physical RAM, fixed in size, split between C: and D:.

If you get a SIGSEGV error message, this is usually not an indication of an instable system, except for some (rare) circumstances where the graphics driver fails. Instead, it is rather an indication that OSDM might have become slightly unstable, possibly because of previous errors or because of inconsistent data. Restarting OSDM is often a good idea in such a case. This should also return all virtual memory to the system, and after some paging activities, overall performance should be close to normal (provided that the page file isn't fragmented). Check for runaway processes after terminating OSDM. Occasionally, especially after crashes, I have seen annotator.exe processes which wouldn't die and still consumed lots of resources.

Hmm. Thanks for the information, Claus. I've noticed sigsegv errors can also spontaneously stop showing up, particularly when dealing with the Move command in Annotation. The segmentation violation errors get pretty nasty at times, in general resulting in a crash within minutes of showing up.

An even better idea in such a case, of course, is to report the SIGSEGV and its circumstances via CoCreate support so that we have a chance to fix those issues .-)

I already do that. It's a bad sign (or maybe a good one? ;)) that CoCreate support reps know me by name.

tom kirkman
03-26-2003, 05:28 AM
In my experience, splitting the page file between partitions causes more problems the fixes, and it seems to make the system run slower. When I changed to having a page file on a single partition (preferably C:) many of my memory issues disapeared.

I have tried several different variations, with the page file completely on c:, completely on d: and split. The best performance was completely on c:. also, keeping the page file as small as possible to achieve the free ram required helps.

Good Luck

Tom

clausb
03-26-2003, 10:44 AM
Some more data points:


http://ntfaq.com/Articles/Index.cfm?ArticleID=14494
http://www.mantiscorp.com/bc/mt36501/misc/windows_tips.htm#pagefile
http://support.microsoft.com/default.aspx?scid=kb;en-us;99768
http://support.microsoft.com/default.aspx?scid=kb;en-us;197379


All sources advise against creating more than one page file per physical disk.

Claus

John Scheffel
03-26-2003, 03:23 PM
Originally posted by clausb
Some more data points:
Good info Claus. There is are some differences, but they also all seem to agree on splitting the pagefile across all your physical hard disks if you have more than one. You can view how the drive letters are distributed on physical disks from Control Panel, Administration Tools, Computer Management.

The recommended size seems to vary between RAM+12MB and 1.5xRAM. In the past we often had to set it higher than this to accomodate large models on PCs that only had 128-256 MB of RAM, but these days that is less of an issue.

May Kung
03-27-2003, 08:06 AM
Hmm. I know with our older boxes, we often had 2 physical hard drives, which would explain why the page file got split between them. Since the newer boxes tend to have only one drive, maybe partitioning it into two "drives," then splitting the page file, makes less sense. I need to check with the sysadmin to see if there was another reason for partitioning (maybe we use some odd configuration that needs it).

John Scheffel
03-27-2003, 09:24 AM
There are some advantages to splitting a single hard dive into multiple logical drives/partitions. You can install Windows and the applications on the C: drive, and keep all your data on other drive letters. If you have a problem you can reformat the boot drive and reinstall the OS and applications without wiping out data stored on the other drives. This can also help with backup since you may only need to backup the data drives. Having multiple drives also allows setting up a PC to dual boot different versions of Windows or other operating systems.

May Kung
03-27-2003, 10:30 AM
I use a partitioned drive on my home rig in that way, with the OS and apps on the primary partition and all data on a separate partition. It definitely makes it easier to back things up.

On the workstations here, we are supposed to put all data on the network, so having a separate partition to keep the OS/apps separate from data wouldn't be the reason for doing this. Maybe Novell Netware prefers it for some reason? We run goofy setups, so who knows. :)