Daz’s bits and bobs

I’ve got some old 250Gb drives that are starting to show their age. I’ve currently got them setup in a 3x RAID 0 config which presents about 750Gb of space.

I’ve got everything on a single partition (meh, i’m lazy). I’ve done various speed tests in the current setup (with all space allocated), but i thought i’d re-image onto a short stroke partition.

I only use about 150Gb of space on my main machine (most of my data is on another box), so i’m going to try creating a 200Gb partition to test if this provides any kind of performance boost.

So reducing my raid 0 from 750Gb to 214Gb, and here are the results…

Before with all 750Gb presented…

Same disks but short stroked to 214Gb….

Conclusion : Yip, seems like its worth it if you have the spare space. Average throughput is up by 10MB/s and seek has improved by almost a third loosing 4ms.

You will get even more of an improvement if you can use a smaller % of capacity per drive and / or more drives for your stripe.

Updated : 07/02/2010

btw – the above was without write-back cache enabled…. if i turned that on i got the following…

Get this when doing a windows update – Error number: 0xC8000408

First check the basics, ensure that windows update is a trusted site and the seucirty level is set corretely within the Zone – test with lower secuirty to see if that resolves the problem.

If that doesnt work try the following;
1) Added the user SYSTEM with every privilege to C: and subs
2) Stopped the “Automatic Updates” service
3) Renamed the C:\WINNT\SoftwareDistribution folder
4) Started the “Automatic Updates” service again

If you dont have sms / sccm client in your gold disk then GPO is the next best thing to get the SCCM client out into your environment.

This is a real nice and clean install script for IE 7 which i have modified to install SCCM. http://www.symantec.com/connect/blogs/installing-application-using-vbscript

This is something i do in the lab so all of my vm’s are able to access iso’s etc (very handy for quick builds). Quite handy doing it through windows since its easiey enough to setup a windows network share to the same location and update various files via that.

This site has some good clear instructions : http://vmetc.com/2008/02/19/create-a-nfs-share-for-vm-iso-files-with-windows-2003-server-r2/

1. On the Windows 2003 Server make sure “Microsoft Services for NFS” in installed. If not you need to add it under Add/Remove Programs, Windows
   Components, Other Network File and Print Services
2. Next go to folder you want to share and right-click on it and select Properties
3. Click on the NFS Sharing tab and select “Share this Folder”
4. Enter a Share Name, check “Anonymous Access” and make sure the UID and GID are both -2
5. In VirtualCenter, select your ESX server and click the “Configuration” tab and then select “Storage”
6. Click on “Add Storage” and select “Network File System” as the storage type
7. Enter the Windows Server name, the folder (share) name and a descriptive Datastore Name
8. Done. Now you can map CD iso’s to your various vm’s.

I’ve used true image for testing packages etc then reverting back to a standard image for further testing. But there can be a problem if the machine updates it domain password then you revert back to the original image. It will not let you logon to the domain if the passwords don’t match.

The way to prevent this is to disable password update so that hte machine does not change its password as per the domain policy.

So if a computer is turned off for three months nothing expires. When the computer starts up, it will notice that its password is older than 30 days and will initiate action to change it. The Netlogon service on the client computer is responsible for doing this. This is only applicable if the machine is turned off for such a long time.

http://blogs.technet.com/askds/archive/2009/02/13/machine-account-password-process.aspx

Warning If you disable machine account password changes, there are security risks because the security channel is used for pass-through authentication. If someone discovers a password, he or she can potentially perform pass-through authentication to the domain controller.

Here is the article that talks about disabling automatic machine account password change.

Key = HKLM\SYSTEM\CurrentControlSet\Services\NetLogon\Parameters
Value = DisablePasswordChange REG_DWORD
Default = 0

Changing this key to 1 will disable password change for this PC. Then you can safely image the machine without having to worry about the machine changing its password with the domain controller.