SureStore DAT40e / Software anyone???

[James Patten]

Have been messing with the drive for over a year trying for a successful backup.
I have used MS backup with 2k, the Tapeware that came with the drive as well as couple of others off web.
Im looking to archive data for shelving. Just want to put and retrieve.
Would also not have to span tapes with a budgeter.

I have gotten NovaBack to back-up and restore but will only use 16Gb of the tape. NovaBack said that using Hardware + software compression will make the backup larger because of doubling the headers, makes sense. Tried it many ways.

If I can't get closer to 40Gb reliable on and off, Im throwing it out the window.
Thanks in advance.
Jim

[Eugeny Brychkov]

Jim,
first of all try HP LTT tests http://h18006.www1.hp.com/products/storageworks/ltt/index.html , especially compression test. Secondly, check bottom dip switched configuration (if availabe there), all on except 3rd off.
Causes of this drive's behavior you see can be:
1. hardware issue. Tapes or drive are not feeling good and thus skipping 'bad' tape areas causing less storage capacity. Check tapes and drive with LTT;
2. DAT40's native capacity is 20GB. It means that without any compression (or ratio 1:1) you can store only 20GB of your data. If ratio will be 2:1, then you can store 40GB, if 10:1 then 200GB. NovaBack said right: you should compress data only once: by hardware (turning drive's hardware compression on) or by software (within backup application or simply zipping files). Please note that if files are not compressable (like .zip, .pdf, .mp3 etc) then no compression should be used any more.
Thus now you should check which data type you're trying to back up: compressable or not? If not compressable (or already compressed) then turn off all the compressions: hardware and BU's software and backup only 20GB is this non-compressable data. If compressable, you can use either hardware compression (fast) or software compression (uses CPU resources, but much effective than hardware compression)
Eugeny