An earlier article on using Windows Server disk quotas received a shocking number of readers. There are a lot more admins paying attention to these making-life-easier tasks than I expected, asking about disk quotas is one of those simple questions that many sysadmin interviewees somehow missed. I’ve always figured Microsoft should require one extra exam completion per year to maintain an MCSE certification. The extra test might actually reduce the number of “paper MCSE’s”, instead of the IT field having to deal with a constantly growing number of them. Although, none of my interviewers at my current employer knew that Microsoft certification transcripts can be verified online.

Getting back to disk quotas, some readers may be interested to know that it’s possible to backup and restore Windows disk quota settings. That linked article references Windows XP, but the same steps also apply to Windows Server 2000 and 2003. Refer to the Microsoft KB article for details; here’s my summary:

Open the quota tab on a disk where quota managment has been enabled.

Select the “Quota Entries…” button at the bottom.

From the Quota Manager, choose the Quota menu > Export > enter a file name and save the settings. Or, drag a quota setting or settings from the Quota Manager to a folder and they will be saved there automatically.

Import by choosing that option from the Quota menu and then navigate to the correct export file.

Windows DFS is supposed to do all sorts of useful things in a domain, like reducing mapped drives, acting as an online backup in the event of downed servers, and caching files locally so WAN usage doesn’t spike (see Microsoft’s DFS Infrastructure marketing info). for Windows DFS basics and setup information: WindowsNetworking.com has a good article explaining Microsoft’s DFS terminology and function, plus I don’t feel like explaining everything and creating the screenshots like they offer.

Like all “infrastructure” tools it adds complexity to the system and requires extra resources to function correctly. In particular, Windows DFS buffers all files that are changed locally before it copies them over the other replicas. Unfortunately, since DFS (as of Windows 2003 SP1) copies entire files and not just the changes it uses a lot of drive space as a buffer - and it can’t even replicate files that may exceed the buffer size. The default buffer size on windows 2000 and 2003 Server is 4GB, so consider not replicating the files causing this problem. After all, pushing 4GB+ files around the WAN isn’t exactly efficient for DFS or any system.

To bump up the DFS buffer size, first make sure you have enough disk space locally to allocate it to the buffer and enough disk space remotely to accommodate the multi-GB mile you’re about to send. Then open regedit and navigate to HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\NtFrs\Parameters\. Change the value of the DWORD “Staging Space Limit in KB” to accommodate your largest files (remember MS still uses binary KB and MB based on multiples of 1024, instead of digital 1000x units).

Adding disks to a new EMC AX100i at one of our offices, the fastest solution to expand the volume sizes was to upgrade them to Windows dynamic volumes and add the new disks to the volume. With no mirroring and plenty of server power, the use of the dynamic volumes was unlikely to impact performance but it would eliminate the need to transfer data off and on the EMC array. The dynamic volumes worked well at first, but turned out to be a bad idea that next time the attached servers were rebooted.

The iSCSI volumes were not attached when the servers started up and the “merge foreign disks” command needed to be run before the array could even be addressed by the server. The only way to keep the error from happening at every reboot was to remove the data, rebuild the volumes on the AX100i, and then move the data back - no time saved after all.

I expect that our use of the Microsoft iSCSI initiator had a lot to do with the problems. An iSCSI HBA would have made the volumes available earlier in the boot process and probably prevented the foreign disk status. Nonetheless, if we had wanted to spend the extra money on HBAs we probably would have bought a fibre channel array instead of iSCSI.

(A May 2005 article also mentions that loading Windows 2003 Server SP1 will result in crashes due to either Navisphere orPowerPath software.)

From a command window, DOS script, or any other shell code the Windows environment variables in the list below can be referenced by adding a “%” before and after the variable name. All of these values are returned as strings. The values can be piped (the “>” command in a “DOS window”) to text files or used in other scripting languages. Also, here are detailed descriptions of some of the more common environment variables.

For example, to find the user profile folder and write it to a textfile:

1. Open a command console (”cmd” at the Run… prompt).
2. Type “echo %userprofile% > C:\file.txt” and press Enter. The path to that resource will be printed to screen. (Without the “> C:\file.txt” the value is printed to a line in the command window)
3. Open the C:\file.txt file and the path to the currently logged on user’s profile will be listed.

Semi-complete* Windows Environment Variable List

• ALLUSERSPROFILE
• APPDATA
• CD
• CLIENTNAME
• CLUSTERLOG (probably only on Windows Server clusters)
• CMDCMDLINE
• CMDEXTVERSION
• COMMONPROGRAMFILES
• COMPUTERNAME
• COMSPEC
• DATE
• ERRORLEVEL
• FP_NO_HOST_CHECK (only with FrontPage installed?)
• HOMEDRIVE
• HOMEPATH
• HOMESHARE
• LOGONSEVER
• NUMBER_OF_PROCESSORS
• OS
• PATH
• PATHEXT
• PROCESSOR_ARCHITECTURE
• PROCESSOR_IDENTFIER
• PROCESSOR_LEVEL
• PROCESSOR_REVISION
• PROGRAMFILES
• PROMPT
• RANDOM
• SYSTEMDRIVE
• SYSTEMROOT
• TEMP or TMP
• TIME
• USERDOMAIN
• USERNAME
• USERPROFILE
• WINDIR

* These are all I could remember or dig up from the one book I looked in. Please add more in the article comments & I’ll add them to the list. Thanks to ByteHead for four recent additions.

Article tagged: Windows, Environment, Variables, Paths, System, folders, user, accounts, userprofile, shell