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DAT24i Recommended Block Size & Buffer Size Settings

Gemma Lahoz Casarramona
Occasional Contributor

DAT24i Recommended Block Size & Buffer Size Settings

I've just had a broken DAT24i tape drive replaced by HP, with the friendly recommendation that I should set the Block Size to 64k in order to avoid shoeshining problems (otherwise my new tape drive would be broken again in no time, they told me).

I've done that, and now my backup software (Veritas BackupExec 8.0) gives me the following error message every time it tries to verify a backup: "An inconsistency was encountered on the storage media in HP0." Can this "inconsistency" be caused by the altered block size or should I be looking somewhere else for the cause of my problem?

I have an HP E60 Netserver with an on-board SCSI controller, 2 hard drives of 9.1 GB (no RAID) and the tape drive, SuresStore DAT24i. The server has got 320 MB SDRAM. I back up about 11 GB of data every day (expected to grow up to 18 GB soon). I use brand new HP DDS-3 data cartridges. I run Veritas BackupExec 8.0 on Windows NT 4.0, SP6a. Firmware version is L005.

Is there a recommended combination of Block Size, Buffer Size, Buffer Count and High Water Count values that will ensure optimal performance and a long life for my tape drive?

Thanks a bunch for your help.
Gemma

 

 

P.S. This thread has been moved from General to Tape Libraries and Drives. - Hp Forum Moderator

1 REPLY
Robert Bean
Advisor

Re: DAT24i Recommended Block Size & Buffer Size Settings

ccording to the HP website located at:

http://www.hp.com/cposupport/information_storage/support_doc/lpg51160.html#P18_1685


It is recommended that the block size is set to 32 KB. Using smaller block sizes will seriously degrade the performance and reliability of the drive. Specifying a larger block size will have little benefit.
Check the block size that is being written. Block size can sometimes be adjusted. For Back-up Exec, follow the steps below to change the block size:

Under File, select Properties.
Click the Configuration tab (Both the buffer and block size can be adjusted here).
Try increasing the block size.
NOTE: Block sizes can also be modified on UNIX (R) systems, check with your system administrator For other back-up software check with the vendor.