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StorageWorks Ultrium 1/8 Autoloader

 
Peter A. Sheshukov
Occasional Contributor

StorageWorks Ultrium 1/8 Autoloader

Our company has purchased the LTO 230 device. We were testing its performance with "HP Library and Tape Tools", OS W2k, SCSI adapter - Tekram DC-390U2W. The results were a bit strange. It showed the write speed of uncompressed data as 30MB/s, read speed - 43MB/s which is much higher than in technical specifications for the device. The results with compressed (2:1, 3:1) data were normal. I wonder how can it be so? Can somebody please explain?
5 REPLIES 5
Curtis Ballard
Honored Contributor

Re: StorageWorks Ultrium 1/8 Autoloader

Was this test with uncompressible data or uncompressed data. That is higher than I would expect for data that can't be compressed but would be reasonable for uncompressed data. My version of LTT doesn't have a test for uncompressible data, 1.6:1 is the lowest compression ratio available. 1:1 would be nice but isn't there yet.
Peter A. Sheshukov
Occasional Contributor

Re: StorageWorks Ultrium 1/8 Autoloader

The test was performed with "zeros" parameter. I thought that it means smth like 'no compression'? If not, what does it mean then?
Dennis_77
Frequent Advisor

Re: StorageWorks Ultrium 1/8 Autoloader

Hi Im having problems trying to install the Storage works 1/8 autoloader.

Its connected to a solaris server and the cell mgr is a windows 200 server.

when i set the tape drive on the hp data protctor software i scan the drive and it fails

Curtis Ballard
Honored Contributor

Re: StorageWorks Ultrium 1/8 Autoloader

The "Zero's" option in LTT means send a data stream of all zero's. That is the most compressible data stream and is primarily used to test the maximum possible throughput from your host to your drive. In most cases this data rate will be much higher than your data rate with normal data. If not then you have a problem somewhere in your system and it isn't able to provide data fast enough.
Curtis Ballard
Honored Contributor

Re: StorageWorks Ultrium 1/8 Autoloader

Dennis - please repost under a new thread with some more details of what kind of failure you are seeing. If the system can talk to the drive and OmniBack is reporting an error you might try posting to the OmniBack section first.