mlandman Posted February 3, 2013 Report Share Posted February 3, 2013 I've just started using Retrospect. I'm a video producer, not an IT guy, so perhaps these are just stupid user errors... I'm using a Dell Powervault 110T on a MacPro running OS 10.6.8 with Retrospect 10.0.1. I"m using TDK Ultrium 3 400/800 data cartridges. I have a script set up to backup files from a hard drive partition to a Media Set "Archive0001". I created the media set, hardware compression is set to 'ON', added the first member to it and ran the script which completed without error. I moved another set of files into the source partition and ran the script again. After running for about 40 minutes retrospect says 'media needed' even though the Members tab in the media sets window says there is 325GB of space left. Retrospect then ejects the cartridge from the drive. I put a new tape in the drive and push 'select media'. The window shows a new tape in the drive labeled '2-Archive0001'. When I push the blue "okay' button nothing happens. If I push the 'done' button I either get a message saying 'an error occurred' or something to the effect of 'this belongs to another media set'. There are no other media sets. I've tried this a couple of times with the same result. How do I add new tapes to the media set while in the middle of a backup? Why is it saying that the new media belongs to another media set when there ARE no other media sets? If hardware compression was turned off I would expect to get a little less than 400 GB storage, but it must be turned on since I'm getting over 400GB. Why does it seem that I am getting over 400 GB storage, but much less than 800 GB on a cartridge before being asked for a new one? I'd really appreciate any assistance anyone could offer. Quote Link to comment Share on other sites More sharing options...
Don Lee Posted February 3, 2013 Report Share Posted February 3, 2013 Compression will give you more than 400, but never as much as 800. The 800 number is the "speed of light", no to be exceeded (or even achieved). You can expect to get something in between, depending on the compressibility of the data you are writing to tape. as a video guy, I'll bet your data is already compressed, so your numbers will be much closer to 400. The "media belongs to another" problem may be as simple as the media not being Retrospect-erased. Go to the "storage devices" tab. Select the tape, and say "erase". That should coax Retro to eat it. (worth a try, at least) Quote Link to comment Share on other sites More sharing options...
prl Posted February 3, 2013 Report Share Posted February 3, 2013 ... as a video guy, I'll bet your data is already compressed, so your numbers will be much closer to 400. ... Even non-compressed video (of natural scenes) will typically compress poorly with the sort of generic compression used in tape drives. Similarly if you try to compress video with zip or gzip. Quote Link to comment Share on other sites More sharing options...
ggirao Posted February 3, 2013 Report Share Posted February 3, 2013 My suggestion (that's working on my systems): create a media set with one tape more than the space you think it occupy; run scripts with sufficient time distance for them not become waiting, ex (script 1 10pm, runs for 1h (including snapshot), script 2 12am next day) Thats my 2 cents Quote Link to comment Share on other sites More sharing options...
Lennart_T Posted February 3, 2013 Report Share Posted February 3, 2013 If you read the fine print on the tape label, you will see that 800GB "assumes 2:1 compression". With real-life data, you will rarely achieve that. Video is ALWAYS compressed, so the hardware compression can't compress it any more. So you will get 400GB per tape. (Non-compressed video doesn't exist, ever.) Quote Link to comment Share on other sites More sharing options...
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