Registry or script 1

[simpletext]

Here's my dilema. I have about 100 laptops out in the field with some in-house software installed. The programmers have informed me that disabling write caching on the harddrive would greatly improve the programs stability. I've written up the instruction for the users to disable write caching via the device manager. These laptops are not connected to our network so there is no remote option of doing this to all the machines. I was wondering if there was a script that I could write or a registry key that I could change that would do this. I want to avoid the users making a mistake.


thanks,
Jaime

 

[Rick998]

It should be possible via a REG file but this is only advisable if you are 100% confident that all the laptops are identical, i.e. hard disks AND the local user is running with administrative privileges.

Navigate to HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Enum\IDE

Within this key you'll see a sub-key for the hard disk, e.g.

\DiskST320011A

Within this sub-key you will find a further 'Parameters\Disk' subkey.

In the 'Disk' subkey is a DWORD setting called 'UserWriteCacheSetting' with a value of 1.

Change the value to 0 to turn off write-caching.

Right-click on the 'Disk' sub-key and export the key.

Double-click on the resulting REG file to import it into the registry on the other laptops then re-boot.

Hope this helps...

 

[bcastner]

A tip of my cap and a star for Rick998.
But I would begin by questioning this premise: "The programmers have informed me that disabling write caching on the harddrive would greatly improve the programs stability."

In a network setting I could be convinced of an issue, but for standalone workstations such as in your case this strikes me as a myth.

 

[simpletext]

Rick 998,

You might find this odd but I don't see a registry entry for the HD in the IDE section. I've looked elsewere and nothing. I did a search for 'UserWriteCacheSetting' an came up with nothing. It seems a little odd to me. I'll keep looking.

bcaster,
Well they are part of a mini network. They are set up in pairs. Wireless peer to peer netowrk and one computer reads the database off another computer. So that would answer your question.

 

[gpalmer711]

The only problem with using a registry edit is the registry key would be different for each machine, For example on mine it is

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Enum\IDE\DiskIC35L120AVV207-0________________________V24OA66A\5&1b4316ad&0&0.1.0\Device Parameters\Disk



Greg Palmer
Free Software for Adminstrators

http://www.palmersoft.co.uk

 

[bcastner]

gpalmer711,
Yes, that was my original concern with forum member rick998's contribution.

The volume ID is part and parcel of the XP authenication, and as a consequence does not allow a general solution.

But go back to my earlier question: I do not see a an issue with drive caching in a shared network setting. I can imagine one, but with current IDE drives I cannot believe an issue exists.

Bill Castner

 

[Rick998]

Simpletext,

Sorry, I should have explained things better...

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Enum\IDE holds the list of hard disks (prefixed with Disk...) and CD-ROMs (prefixed with CdRom...)

What follows after each prefix is the make/model of hard disk or CD-ROM. A standard laptop (i.e. with only only hard disk) should show just one 'Disk...' entry. The 'Disk...' prefix can be followed by anything, e.g. DiskMaxtor, DiskST380021A, etc.

You won't see any sub-keys within the 'Device Parameters' key until 'write-caching' is turned off for the first time.

When 'write-caching' is turned off then a refresh of the registry will show that 'Device Parameters' now has a newly-created 'Disk' subkey with 2 further sub-keys - '(Default)' and 'UserWriteCacheSetting'.

Even if you turn 'write-caching' back on again, the 'UserWriteCacheSetting' entry will remain but with its value changed from 0 (off) to 1 (on).

In view of bcastner and gpalmer711's very valid points, I double-checked one of our sites that have PC's cloned using Ghost and the registry settings for 'HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Enum\IDE\Disk...' on different PC's ARE identical.

If your laptops aren't identical, i.e. clones of each other then I'm afraid my idea is a non-starter.