🚀 go-pugleaf

pete$no$pam@pdlmail.demon.co.uk wrote in message <924360205snz@pdlmail.demon.co.uk>...
>In article <371883B7.E5E40955@shanti.demon.nl>
>           chris@shanti.demon.nl "chris" writes:
...
>> > >... 'write behind cache'?
>> > 
>> > A slight performance penalty,
>> > though only when you are writing something to disk AFAIK.
>> 
>> If you could tell me what that is I've definitley learned some more...

Not sure what you are asking about, hopefully one of the following 
answers covers it.

write behind cache, aka. deferred disk writes:
  on write operations the OS may deside to cache the data and
  only write it to disk in a little while, 
  on Win9x counted in milliseconds, on unix in seconds, AFAIK.

performance penalty:
  [negative] impact of choice of configuration on performance of system.

AFAIK:
  as far as I know

Putting numbers on the performance penalty would be difficult.
It does not impact normal operation though. It would only be
seen when you (or the OS) save something to disk.

>There exists a possible problem on win32 OSs with deferred
>disk writes and "opportunistic file locking" in a networked
>environment.  This has been identified by Lotus Dev Corp. as
>it affected cc:Mail - take a look at Lotus Technical Document
>No. 144293 which you get via ftp or http:
>
>ftp://ftp.support.lotus.com   /pub/comm/ccmail/technotes/AllProd
>http://www.support.lotus.com  (Search the cc:Mail KnowledgeBase)

I've always had the notion that Win95's write-behind cache was 
kind of dodgy - it one of those things I usually turn off.
I could not find anything on the site about similar problems 
with Win98, but there's certainly no harm in disabling it. 

<quote>
VIII. Microsoft Windows 95 and Novell Client32

All the changes listed below are made by CCREGMOD to the Windows 95 Registry. If you are using Microsoft Windows 95 and Novell's Client32, a number of changes need to be made in the Registry. These changes help ensure the robustness of cc:Mail in the Microsoft Windows 95 environment. All of these settings are located in:

HKEY_LOCAL_MACHINE\Network\Novell\System Config\Netware Dos Requester\

Cache Writes:

Default: Yes
Changed to: No

Opportunistic Locking:

Default: Yes
Changed to: No

Note: If any of the above keys do not exist, CCREGMOD will add them to the Registry. 

For all Windows 95 workstations not running Novell Client32, the following change is made:

HKEY_LOCAL_MACHINE\System\CurrentControlSet\control\FileSystem

DriveWriteBehind
Default: FF FF FF FF
Changed to: 00 00 00 00

By setting this value to 0, the Windows 95 workstation will not use a write behind cache.

Note: If any of the previous keys do not exist, CCREGMOD adds them to the registry. 
</quote>

-- 
Thomas Schodt 
tschodt@nospam.nospam.dk
(drop one nospam. to reply)