Blog: Networking

When working with HP Ultrium tape drives, it is sometimes a challenge to get them to run at speeds even close to the advertised maximum. Sometimes there are questions as to how to troubleshoot and how know you are getting the most out of the drive. Here are some tips: [more]

• Most HP modern Ultrium drives have a hardware compression feature. In order to get even close to the advertised speed of the drive, you must ensure that the hardware compression is enabled on the drive. You can do this with the HP Library and Tape Tools utility. Without it, you will get approximately half of the advertised speed.
• If you are using Backup Exec with an Ultrium drive, use the Symantec drivers that are provided on their website and make sure the drive you are using is on the HCL for the version of BE you are using. Only switch to the HP/OEM driver if you experience issues with media robotics when moving/inventorying media.
• If you are using a tape library or autoloader, use the HP/OEM driver for the media changer/robotics and the Symantec driver for the drive. Symantec does not make drivers for the robotics.
• Make sure that you are not using a SCSI channel that is connected to a RAID card. This can seriously impact performance of the drive. Best possible scenario is an Ultra320 SCSI card on a dedicated 64-bit PCI bus. Make sure the SCSI card drivers are up to date.
• There are two types of autoloaders/libraries: LUN based and SCSI ID based. The difference is the way the device presents itself to the OS. LUN based devices share a SCSI ID and present different LUNs to the OS for the media changer and the drive. SCSI ID devices present two different SCSI IDs . Backup Exec works best on SCSI ID devices, but either will work. If the device you are working on allows you to choose LUN based or SCSI based, choose SCSI based.
• Make sure the SCSI bus of your device chain is properly terminated. If using LVD SCSI, make sure you are using an LVD/SE terminator. Do not put more than two SCSI devices on the same SCSI chain as the tape device.
• When testing performance, do a backup to local disk to test performance. If speeds are significantly faster, you should further troubleshoot the tape device because data CAN be backed up faster; the bottleneck is the tape device. If speeds are about the same, the bottleneck is the BE remote agent. Data cannot be presented to the device fast enough to keep it busy. In this scenario, troubleshoot the hosts for performance increases.
• On the Backup Exec media server, disable the "Removable Storage" service. It has been known to cause issues with Backup Exec since version 8 and up.

 

Shared folders can be used in a VMware Virtual Machine (VM) to map a VM folder to a Host folder. However, this capability is a "special feature" and not installed by default. If you try to use it and it is NOT installed, it just doesn’t work… no error and there is no reason given for not working.

There is an order of operations to defragment the disks of a (VMware Workstation) VM.

1. First, use the defragmentation utility in the operating system running on the VM to defrag… just like a real machine.
2. Use the Utility provided by the VM software to defragment(machine must be powered down). VM->Settings->Hardware->Hard Disk->Utilities(Button).
3. Use the defragmentation utility in the HOST operating system to defrag the disk files of the virtual machine.

If you are running out of space on the "C" drive on a system, one way to avoid the hassles of rebuilding the system just to gain space is to use the junction point feature of Windows. This will allow you to move entire folders from the C drive to another drive, thus freeing physical space.

There is a Microsoft KB article on how to create and manipulate NTFS junction points and another article with the best practices for Sysvol maintenance.

Windows does not come with a tool for creating junctions.  The Win2K Resource kit includes the linkd program for creating junctions, but if you don't want to purchase that there is a free Sysinternals tool called Junction that can be used to create junction points in Windows.

In Active Directory Users and Computers there is an Email Addresses tab that lists email addresses for the user.  One of these (for each protocol) is selected as the Primary.  The primary address will be the one that a user's outgoing email appears to come from.  But there is also a General tab where one can enter an email address for the user. This also causes that user's outgoing email to appear to come from that address.  Normally, changing one also changes the other.  But if you are running Active Directory Users and Computers from a machine that does not have the Exchange Server tools installed, the Email Addresses tab is not there and changing the email address on the General tab will not change the primary.  Actually, anything can be entered in that field on the General tab, even invalid domains.  So it is recommend to always make user account changes on the Exchange server, or at least on a system that has the Exchange server tools installed.  And use the Email Addresses tab to change user's email addresses.

Some email servers perform some verification on the sender's email address and may reject it if the domain is invalid.  Nothing can send a bounce message either because the email address does not work, so the sender will not know the email was not delivered.

When upgrading VMware Workstation from a previous version (in this case, version 4) to version 6, snapshots can prevent the virtual machines created under the old version from being upgraded to version 6.  There are two solutions: [more]

1. Prior to installing version 6, remove all snapshots from the virtual machines.  Also, it is a good idea to make sure all the virtual machines have been shut down gracefully and there are not any .lck files associated with them.
2. If you have already upgraded to version 6 and still have snapshots, you may get an error message when attempting to upgrade the virtual machine that says something along the lines of, “this virtual machine cannot be upgraded because it has a legacy snapshot.”  When you go to remove the snapshot, the option is grayed-out.  It fix this issue without reverting the old version of Workstation, do the following steps:
   1. For the virtual machine you want to upgrade (vmware1, as an example), rename the file vmware1.vmx.sav to something else.
   2. Open the file vmware1.vmx in WordPad and delete these lines:
      1. undopoints.seqNum = "0"
      2. ide0:0.mode = "undoable"
      3. undopoint.restoreFromCheckpoint = "FALSE"
      4. undopoint.checkpointedOnline = "FALSE"
      5. ide0:0.redo = ".\VM1- XP Pro.vmdk.REDO_a05076”
   3. Save and close vmware1.vmx
   4. Open the virtual machine in Workstation 6 and choose the menu item “VM -> Upgrade or Change Version” to update the version.

If you ever get this error : "Run-time error `339`; Component `MSCOMCT2.OCX or one of its dependencies not correctly registered: a file is missing or invalid."
This error is indicating that your workstation installation is missing a file that should have been installed when the OS was installed.
 
To fix the problem, simply download MSCOMCT2.OCX or copy it from another machine.
 
You then need to put it into the correct directory on the problem machine. It should look something like this:
 
%WINDIR%\SYSTEM32\REGSVR32.EXE %WINDIR%\SYSTEM32\mscomct2.ocx
 
You then need to register the file by typing in the following command:
 
C:\WINNT\SYSTEM32\REGSVR32.EXE
C:\WINNT\SYSTEM32\MSCOMCT2.OCX (on Windows 2000)

C:\WINDOWS\SYSTEM32\REGSVR32.EXE C:\WINDOWS\SYSTEM32\MSCOMCT2.OCX (on Windows XP)

We used to run bemcmd91.exe with a long list of parameters to export and import Backup Exec jobs and settings.  With version 10, there is now a gui, BEUtility.exe. Read http://seer.support.veritas.com/docs/274778.htm.  This document says "BEUtility will not copy media sets that are not currently assigned to a job". I assumed this means that it will copy media sets that were assigned to a job, but it does not. It also says it will copy the alert configuration, but it does not. You need to go through all the settings and check them.

One of out customers was not able to get to the Internet.  I was able to connect to the router, but could not ping the ISA server.  Shortly, I could get on the server, but when going through the start menu, it stopped responding and I finally got disconnected. I could no longer ping it from the router. Then in a little while it came back. I was able stay connected long enough to look at the event log and found messages that said "Remote Access Connection Manager failed to start because it could not create buffers. Restart the computer. Access is denied." I researched this and found http://support.microsoft.com/kb/842696 and http://support.veritas.com/docs/285593 which both say the tape drivers need to be updated. I downloaded the driver installation file from Veritas (Symantec) and put it on a CD and went on site.  The internal LAN was working fine. I got on the server and found that I could not ping the router. I installed the Veritas (Symantec) device drivers and rebooted and that seems to have corrected it. The version of the HP tape driver was "5.1.23.0" before and now it is "5.1."