Compression ratios

[jcanfer]

I'm using a Compaq SSL2020 which offers 2:1 hardware compression and I've got BENT 8.5 for Win2000 setup to use this hardware compression.

However, do I just assume that I'm getting 2:1 compression on my backups or is there a way of actually checking this?

Thanks in advance.

Jim

 

[Guest_imported]

Look how much is stored on one tape. This is the ammount of data without compression. You can find this at Devices->Slots then select a slot (with tape) ->properties-stat's. Bytes written is from the last overwrite.
Don't expect a 1:2 ratio though. In todays world of MP3 MPG JPG GIF etc.etc. much of stored data, even word-powerpoint-access files, are allready compressed. It's very data type depending which ratio will achieved.
GL

 

[RSA]

It is rare to get full quoted compression, it depends upon what you are backing up. Video and audio files rarely go below 2/3 of the origional size (sometimes not much at all), while plain text documents may get a lot smaller, some files compressed already may even end up larger!

I used to have a Compaq 4/16 DAT drive (until the server was nicked), but I rarely got more than 5.4GB on a tape (and then it was 5.6GB), so always take the quoted maximum with a metaphorical pinch of salt.

 

[johnny99]

When we talk about NT files I would expect something like 1:1,3 to 1:1,5
/johnny