San Client Slow Throughput
Hi,
I would have thought the setting in the text below is set automatically these days. I used it back in the days of LTO-2 to get the OS to write bigger blocks, as specfied in SIZE_DATA_BUFFERS in NetBackup. Take a look and see if its set to 65 (the note says 33 but that is for 128k)
Solution
The Windows media server that wrote the backup image to tape media, wrote the backup using a 128 K size data block.
The Windows Media server performing the import is not the same media server that performed the backup, however does contain the same SCSI card for the tape device.
Solution:
Set the Windows Registry for the SCSI card to read and write in 128 K blocks.
Set the MaximumSGList entry under the path HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\<SCSI_CARD>\Parameters\Device.
This is set to a decimal value of 33.
Procedure:
Warning: Incorrect use of the Windows registry editor may prevent the operating system from functioning properly. Great care should be taken when making changes to a Windows registry. Registry modifications should only be carried-out by persons experienced in the use of the registry editor application. It is recommended that a complete backup of the registry and workstation be made prior to making any registry changes.1. Click Start | Run and type regedit and click OK
2. In regedit go to the following key:
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\<SCSI_CARD>\Parameters.
The <SCSI_CARD> entry will depend on the type of SCSI card that is in the server.
3. Create the Device key if it does not already exist under Parameters. If the Device key exists go to step 6.
4. Highlight Parameters then right-click and select New | Key
5. Name the new key as Device
6. Highlight the Device key then right-click and select New | DWORD Value
7. Give the DWORD Value the name MaximumSGList
8. Double-click on MaximumSGList and enter a decimal value of 33
9. Close regedit
A reboot of the server will be required to enable the changes.
