Smart Array 6402 Max block size 1

[Ligae]

Can anyone help me on how to change maximum block size for Smart Array 6402 in Windows Server 2003?

Here is current settings:
mt -f \\.\tape0 stat
\\.\tape0:
Media Blocksize = 0
Media Partition Count = 0
Media is not write protected
default blocksize = 65536
maximum blocksize = 65536

 

[605]

Such is described in the Performance Tuning Guide which is available via the web:

http://www.legato.com/resources/manuals

 

[Ligae]

Thanks for your info about Performance Tuning Guide.

I check from Device Manager, SmartArray 6400 is using cpqcissm.dll and cpqcissm.sys.
Then I go to registry in this location:
HKLM\SYSTEM\CurrentControlSet\Services\cpqcissm\Parameters\Device.
I added "MaximumSGList" to 257.

The maximum block size I want to set to is 1048576 (=1024 KB). That's why I set to 257 = (1024/4)+1

Then I reboot the server, but still the mt -f \\.\tape0 status shows me maximum blocksize is 65536.

Perhaps anyone can guide me on where/how should I configure it?

 

[605]

I am pretty sur ethat you have to relabel the media.

 

[Ligae]

The scenario of my problem can be described as follow:
Backup server A at Data Center:
HP Ultra320 SCSI adapter used to connect MSL-5026 Library with one SDLT-320 drive (run NetWorker 7.2 on Windows)
When I run "mt" it shows maximum blocksize=1048576
I took one of the backup media backup with this server to other site (say office B)

At office B:
Server B with Smart Array 6400 used to connect one standalone HP SDLT-320 tape drive. (run NetWorker 7.2 on Windows)
When I run "mt" is shows maximum blocksize=65536.
Therefore I couldn't read the media.

I have tried modify blocksize at registry and Devices from Legato.

Is the problem caused by different SCSI controller? This is what I suspect and because the drive is the same type. The only difference is first one come with MSL5026 and the other is standalone drive.
If I plug and use the same HP Ultra320 SCSI controller, will it solve the problem?

Thanks "605" for your quick response.

 

[605]

OK, if you want to read media, it must match the found block size. The mt program reports the faound block size but the device's driver also must be adjusted.

Whenever you exchange data between two devices, make sure that they both work with the same block size.

 

[Ligae]

And I have problem in changing blocksize in Smart Array 6400 in Windows 2003.
I have followed in Performance Tuning guide, but still the block size were not changed. :-(

I think it is because block size of Smart Array not controlled and configurable via "MaximumSGList". Or may be not configurable at all?

Does the maximum blocksize depend on tape drive model or SCSI controller?
One can say this is to simulate disaster recovery using offsite media.

 

[605]

The max block size is set for the device.

For FC drives, the size does not matter. However, for SCSI, the drivers usually block after 64KB. This is why you have to force the driver to be capable to support the device block size via the increased Scatter/Gather factor.

Unfortunately i do not know the tech details of the Smart Array 6400 at all. So i can just give you general advice.