OS/2 Disk "thrashing" 
Author Message
 OS/2 Disk "thrashing"

I'm having an intermittent problem with VisualWorks 2.0 under OS/2 2.1.  Intermittently, VW starts
to crawl.  E.g.  I drag my cursor over the menu and my harddisk starts "thrashing" like crazy.
Whatever I do, from opening a window, to scrolling down a list, the harddisk is constantly being
accessed.  I'm assuming VW is writing stuff to the swapper, but have no proof.
I have plenty of harddisk space available to my swapper file (>100 meg), I have 32 meg of ram.
I have TCP/IP for OS/2 running in the background.  I've tried contacting ParcPlace about this,
but have not had a solution.
The only way I've been able to cure the problem (and I know this sounds weird but...) is to close
all open windows, do a GC, shut down VW, shut down OS/2, shut off the machine and go home for
the night.  The key being to leave the machine off for awhile which leads me to believe that
there is some kind of time based thing going on here?
Anyone else having this problem?  Any solutions?
Thanks
bob



Mon, 22 Jun 1998 03:00:00 GMT  
 OS/2 Disk "thrashing"

Quote:

>I'm having an intermittent problem with VisualWorks 2.0 under OS/2 2.1.  Intermittently, VW starts
>to crawl.  E.g.  I drag my cursor over the menu and my harddisk starts "thrashing" like crazy.
>Whatever I do, from opening a window, to scrolling down a list, the harddisk is constantly being
>accessed.  I'm assuming VW is writing stuff to the swapper, but have no proof.
>I have plenty of harddisk space available to my swapper file (>100 meg), I have 32 meg of ram.
>I have TCP/IP for OS/2 running in the background.  I've tried contacting ParcPlace about this,
>but have not had a solution.
>The only way I've been able to cure the problem (and I know this sounds weird but...) is to close
>all open windows, do a GC, shut down VW, shut down OS/2, shut off the machine and go home for
>the night.  The key being to leave the machine off for awhile which leads me to believe that
>there is some kind of time based thing going on here?
>Anyone else having this problem?  Any solutions?
>Thanks
>bob


Bob, the swap file will grow as you consume memory. There are some monitor programs
out there to track cpu/swap file size etc. For example 'OS/2 System Resource Monitor'

on the Hobbies BBS/CD

After your swap file grows and the demand goes away it will at some point resize downward
this collapse is disk intensive.

First are you using 256 colors on your video card, or is it 64,000 or millions (16 or 24 bit)
versus 8 bit? At 16bit or 24bit raster images take lots of memory.

Second you didn't mention the amount of memory  you have in your Box.

Third look at
ObjectMemory>>printSpaceReport
Read the comments and execute it as shown in the comments.

For my small test image it shows in the Transcript.

3447652 bytes available
computing space usage...
139265 objects, 6075044 bytes in use

Or a good 9MB of memory used by VW V2.0 on my OS/2 V3  (Warp) image.

Now  under your thrashing conditions I wonder what the values are?

John
VisualAge/VisualWorks Smalltalk consulting



Tue, 23 Jun 1998 03:00:00 GMT  
 OS/2 Disk "thrashing"
John,
Thanks, I've seen how the swapper grows and shrinks, but this problem
seems to happen regardless of the swappers size.  I've had it happen with
a size > 13 meg and a size < 6.  It's pretty strange.  At first I thought
it was the way I was using BOSS files, but this will occur when I'm NOT
using them.  The problem also seems to occur most frequently when I've had
a system problem (i.e. OS/2 locks up).  I'll look at the
ObjectMemory>>printSpaceReport.  Must have missed, I stated I have 32 meg
ram.  I'm using 256 colors.


Tue, 23 Jun 1998 03:00:00 GMT  
 OS/2 Disk "thrashing"

Quote:

>I'm having an intermittent problem with VisualWorks 2.0 under OS/2 2.1.  Intermittently, VW starts
>Anyone else having this problem?  Any solutions?

1. There was a major rewrite of the swapping code between 2.1 and Warp which
reduced swapping in general.
2. The amount of cache memory on your PC can significantly influence performance.
The more the merrier ...

Quote:
>Thanks
>bob


Steve


Thu, 25 Jun 1998 03:00:00 GMT  
 OS/2 Disk "thrashing"

Quote:

> ... my harddisk starts "thrashing" like crazy.
> ...

I have seen this problem when using Envy.  The fix is a good disk cashe.  
If you get it right, the thrashing should go from the disk light being ON
continuously to being OFF all of the time except for a momentary flash of
the hard disk light every few seconds.


Fri, 26 Jun 1998 03:00:00 GMT  
 OS/2 Disk "thrashing"

Quote:


>>I'm having an intermittent problem with VisualWorks 2.0 under OS/2 2.1.  Intermittently, VW starts

>>Anyone else having this problem?  Any solutions?

>1. There was a major rewrite of the swapping code between 2.1 and Warp which
>reduced swapping in general.
>2. The amount of cache memory on your PC can significantly influence performance.
>The more the merrier ...

We had a similar problem with the VisualWorks, OS/2 2.11 combination a while back.  Several people's images were thrashing while mine was fine.  After looking at the differences b/w machines, we found that mine did not have any CD-ROM drivers loaded.  After unloading the drivers all the images stopped thrashing...  Since the CD-ROMs were only used for listening to (audio) CDs, we made this our 'official' fix.  We haven't looked into the real problem since.

Good Luck.

Chad Stansbury
American Management Systems



Fri, 26 Jun 1998 03:00:00 GMT  
 
 [ 6 post ] 

 Relevant Pages 

1. string.join(["Tk 4.2p2", "Python 1.4", "Win32", "free"], "for")

2. "Hard Disk Surfer" Demo Available

3. "C Express" Disks

4. "Get Disk Free Space" for NTFS

5. VST: "Disk" misassignment

6. BEGIN{want[]={"s1o", "s2o", "s2q", "s3q"}

7. Disk thrashing

8. MS Powerstation 4.0 / disk thrashing problem

9. Parsing ""D""?

10. "Fifth", "Forth", zai nar?

11. Ruby "finalize", "__del__"

12. beginners "let"/"random" question

 

 
Powered by phpBB® Forum Software