Author: bjoern_busch <bjoern.busch AT gmail DOT com>
Date: Wed, 11 Jun 2008 03:22:48 -0700 (PDT)
Hello, I apologize in advance, if a similar question has been asked before, but I have been searching for about 3 days now and all the answers that I could find didn't solve my problem. Here is my si
What is the native capacity of the tapes? (Vs advertising-driven compressed capacity) I find I only achieve 1.2:1 compression ratio on full backups, vs the 2:1 or 3:1 used in advertsing figures. Fill
Author: bjoern_busch <bjoern.busch AT gmail DOT com>
Date: Wed, 11 Jun 2008 03:31:59 -0700 (PDT)
The tapes are HP-DDS3 125m tapes. Compressed 24GB and the box says assuming 2:1 compression rate. Maybe that's really the issue. The strange thing is really that in the one version of btape I can fil
It is. The real capacity is 12Gb. Try this: tar Slcf - / | gzip -1 | wc And see what's reported. Compare that with what df says is the amount of disk space used. That will give you an idea of achieva
Author: Allan Black <Allan.Black AT btconnect DOT com>
Date: Wed, 11 Jun 2008 12:00:59 +0100
There is probably a difference between the way the two versions of btape generate the buffer to be written, resulting in one generating data which comresses much better than the other. Try using e.g.
Author: bjoern_busch <bjoern.busch AT gmail DOT com>
Date: Wed, 11 Jun 2008 04:04:30 -0700 (PDT)
Well, I guess I don't like the answer, but I will have to accept that... i would have rather heard, I'm just an idiot and there is a fix :) So I guess 1.29 btape uses compressable data then and 1.36
Author: Ryan Novosielski <novosirj AT umdnj DOT edu>
Date: Wed, 11 Jun 2008 15:59:10 -0400
If you can move to a DDS4 tape, you'll get 20GB uncompressed. DAT72 (DDS5 with a different name) gets 36GB. There is not much difference in media prices these days if you can come up with a drive. -
Author: bjoern_busch <bjoern.busch AT gmail DOT com>
Date: Thu, 12 Jun 2008 00:14:33 -0700 (PDT)
Yeah, it would be great, if we could just update our drive and everything, but unfortunately they are expensive and I'm not sure if my company is willing to spend the money on that drive right now. I
DAT/DDS are inherently unreliable, apparently due to the narrow tape width. (8mm helical scan tape formats such as AIT are fine) You might want to price up a LTO or DLT drive - LTO has a number of fe
How expensive is data loss? -- Check out the new SourceForge.net Marketplace. It's the best place to buy or sell services for just about anything Open Source. http://sourceforge.net/services/buy/inde
Author: bjoern_busch <bjoern.busch AT gmail DOT com>
Date: Thu, 12 Jun 2008 04:14:25 -0700 (PDT)
How much would you pay for such a drive? Just a rough guess for my orientation. And sure, data loss would be way more painful / expensive than a new drive, but I think right now the tendency is towar
That depends on how much storage you need. An external Quantum LTO2 drive can be had for about EUR 1000, these are 200Gb raw capacity and the tapes are ~ EUR 22 each. AIT drives start at about EUR 50
Author: Paul Shields <paul.shields AT blueyonder.co DOT uk>
Date: Thu, 12 Jun 2008 12:42:59 +0100
It may not be for everyone, but I find ebay a real treasure chest for enterprise-level backup devices. I recently picked up a Dell PV132T with LTO-3 drive and 24 slot autoloader for £500. I was the o
Author: Chris Hoogendyk <hoogendyk AT bio.umass DOT edu>
Date: Thu, 12 Jun 2008 08:30:07 -0400
Nothing is ever 100%. I've had reasonably good luck with HP branded DDS drives and Fuji or Sony branded DDS tapes. Granted, they are old technology and not up to current needs. But choice of brand is
Produce a "Cost of Not Implementing" report. Make it clear that you will not be responsible for data losses not attributable to backup hardware failure. That won't happen with Bacula. More likely, yo
Author: "John Drescher" <drescherjm AT gmail DOT com>
Date: Thu, 12 Jun 2008 09:22:36 -0400
Since AIT was mentioned. I would like to caution people about this. The drive makers assume a 2.61:1 compression instead of a 2:1 like every one else. Sure the compression may be a little better but
I only ever work off uncompressed drive capacity. Compression is nice when it works but the native capacity is the most important part. Sony make a similar assumption for SAIT, but that format now ap
Author: Chris Hoogendyk <hoogendyk AT bio.umass DOT edu>
Date: Thu, 12 Jun 2008 14:28:17 -0400
Manufacturer's claims for compression should always be taken with a grain of salt (also known as knowledge) for all drive types. I can contrive a file that will give me unbelievably huge compression
Author: Chris Hoogendyk <hoogendyk AT bio.umass DOT edu>
Date: Thu, 12 Jun 2008 17:19:22 -0400
been there. done that. We convinced the other department to invest in a better backup system after a serious building wide power glitch (an emergency generator fired 220 down all the 110 lines in the