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HPE Tape Libraries - Changing Block Size in a QLogic HBA in Windows 2008

Title: HPE Tape Libraries - Changing Block Size in a QLogic HBA in Windows 2008
Object Name: mmr_kc-0123734
Document Type: Support Information
Original owner: KCS - Storage Libraries
Disclosure level: Public
Version state: final
Environment
FACT:HPE StoreEver ESL G3 Tape Libraries
FACT:HP ESL E-Series Tape Libraries
FACT:HP EML E-Series Tape Libraries
FACT:HPE StoreEver MSL6480 Tape Library
FACT:HPE StoreEver MSL2024, MSL4048, MSL8048/8096 Tape Libraries
FACT:HPE StoreEver 1/8 G2 Tape Autoloader
Questions/Symptoms
SYMPTOM:QLogic FC Utility : qlfc.exe
Cause
CAUSE:With the new models of Data Center using virtualization, the backups are changing. It occurs often that user needs to tune the backup application in order to use higher block size than in the past. In some system, there may be some limitations due to the HW, in other system, there may be some limitations due to the drivers.

Example: When one tries to format a tape with 1024 KB block size in data protector, then one may get an error message saying:


					Cannot write to device ([87] The Parameter is incorrect.)
				

This indicates that the OS or the HBA are unable to transfer the data using that block size.

Some HBA have a physical limitation and cannot handle block size bigger than 256 KB or 512 KB. Newer HBA, even if they support 2048 KB (2 MB) Block size, are limited to 512 KB.
Answer/Solution
FIX:

In order to change the transfer block size limit, HP and QLogic include in the driver package a CLI command called QLogic FC Utility : qlfc.exe

The command line utility, \Program Files\hp\qlogic\qlfc.exe is used to modify the maximum data transfer size used by the HBA. A help.txt file is located in the directory with the utility which provides additional information. 

Example:

Microsoft Windows [Version 6.0.6001] 
Copyright (c) 2006 Microsoft Corporation.  All rights reserved. 
C:\Users\LabAdmin\Desktop\Softwares\91925_x86_FC_cp014207>qlfc 
QLogic FC Utility 

					
qlfc [-list] [-tsize [/fc | /fcoe [/set [64 | 128 | 256 | 512 | 1024 | 2048 | default] ] ] ] 
-list (List all HBA instances)
-trace (Capture driver trace of all HBA instances)
-tsize ( Show current transfer size setting for both fc & fcoe)
-tsize /fc (Show current transfer size setting for fc)
-tsize /fcoe & nbsp (Show current transfer size setting for fcoe)
-tsize /fc /set value (Set transfer size parameter for fc)
-tsize /fcoe /set value (Set transfer size parameter for fcoe)

				
Example:

c:\>qlfc -list
c:\>qlfc -trace
c:\>qlfc -tsize
c:\>qlfc -tsize /fc
c:\>qlfc -tsize /fc /set 256
c:\>qlfc -tsize /fc /set default    

				
This will allow the user to see the actual values and allow the user to change these values.
In Windows 2008 one needs to run this command with administrator right.
The user can open a DOS prompt in administrator mode typing in the Run /Search line CMD then press the CTRL + SHIFT + ENTER key, or right click on the CMD icon and select Run as Administrator.

NOTE: Changing the default transfer block size is not recommended. User may end up in issue if user needs to recover the data from a different system that do not support that block size. The change of this parameter should be done only if the user has considerate all the possible implication this may cause in the future.

NOTE: After changing the parameter, the driver needs to be reloaded, and then a reboot is required.

			

© Copyright 2016 Hewlett-Packard Development Company, L.P.

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