Author Topic: DISKCACHE causes delays on JFS volumes  (Read 3709 times)

Sergey Posokhov

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DISKCACHE causes delays on JFS volumes
« on: June 16, 2014, 10:36:21 am »
Since august 2013 (i.e. during the last year) I saw random delays from 3 to 15 seconds on JFS volume when reading files or directory nodes. This also affected to WPS and PMView 2000 - they both hanged randomly.

Defragfs.exe didn't help.

Then I added "REM" before "DISKCACHE=..." statement in "Config.sys" - and all these delays gone away.

Where can I report about this bug?..

G. M. Anchieri

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Re: DISKCACHE causes delays on JFS volumes
« Reply #1 on: June 16, 2014, 10:47:20 am »
I have this statement in my config.sys file: DISKCACHE=1024,LW,32
and  never had problem with my numerous JFS disk, probably that format it's also the standard if this statement was missed.   

Greggory Shaw

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Re: DISKCACHE causes delays on JFS volumes
« Reply #2 on: June 16, 2014, 07:54:26 pm »

Then I added "REM" before "DISKCACHE=..." statement in "Config.sys" - and all these delays ...

I was wondering about that statement and my SSD. I had a lot of problems on shutdown (chk disk on next startup).  But, then it just corrected itself or something - I didn't do anything.


Greggory

ivan

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Re: DISKCACHE causes delays on JFS volumes
« Reply #3 on: June 16, 2014, 10:15:58 pm »
As far as I know DISKCACHE is only of use with FAT formatted drives so is useless with a JFS system.  Also it is not needed with floppy disks or anything formatted as FAT32.

Doug Bissett

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Re: DISKCACHE causes delays on JFS volumes
« Reply #4 on: June 16, 2014, 10:25:46 pm »
Quote
Then I added "REM" before "DISKCACHE=..." statement in "Config.sys" - and all these delays gone away.

Odd. The DISKCACHE statement is to configure the FAT cache (not for diskette drives). It shouldn't have anything to do with JFS (but I won't say that it doesn't).

This is what ConfigTool has to say about REMing it: "If you have a FAT partition on your hard drive and you REM this statement, OS/2 will automatically set up a 64k cache by default". I am not sure what it does if there is no FAT partition. You may find that any FAT device (other than diskettes) will not work without it.

Andy Willis

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Re: DISKCACHE causes delays on JFS volumes
« Reply #5 on: June 17, 2014, 05:21:37 pm »
This is what ConfigTool has to say about REMing it: "If you have a FAT partition on your hard drive and you REM this statement, OS/2 will automatically set up a 64k cache by default". I am not sure what it does if there is no FAT partition. You may find that any FAT device (other than diskettes) will not work without it.
I have had it remarked out for many years now as the only FAT drive I have is a rarely used USB stick (I have most with FAT32 or JFS - maybe one HPFS).  As the USB stick still works despite the REM and no FAT partition on the drive means that either it set up the 64k anyhow or there is no cacheing but it still works.