Tell me a story about tape drives.
I'm looking for any recommendations/horror stories about tape libraries and Linux.
I've got a Sun StorEdge L9 that I've been thinking of putting on a Linux box. It's an HP Ultrium C71471A (er something) that's been rebranded as a Sun device. I've read it has different firmware than the HP version, but according to information at http://amanda.org some folk(s) are using it with Linux.
Then I read that this thing is no longer made, let alone supported, therefore I don't want to depend on it ultimately, but in the short term, it likely outperforms nothing.
Another thing that I'm not sure of yet, is the capacity of the tape library for this thing. On the high end, it may be 900GB, but based on what I've seen so far I think it's a measely 360GB which probably isn't going to cut it... for long.
Anybody using high capacity backup system they're are really happy with?
Thanks.
-- Dave Hull http://insipid.com
-----Original Message----- From: kclug-bounces@kclug.org [mailto:kclug-bounces@kclug.org] On Behalf Of Dave Hull Sent: Saturday, November 20, 2004 2:46 PM To: kclug@kclug.org Subject: Linux Backups: Tape Drives
Tell me a story about tape drives.
I'm looking for any recommendations/horror stories about tape libraries and Linux.
I can share a few horror stories - but am pressed to get ready for a date right now so I'll be brief.
I had a client some 7 years ago that had SCSI controller X, it shot craps, and data couldn't be recovered from drives because the firmware on the RAID controller was likewise not available, used a "funky" algorithm, etc. (Novell was part of that problem IIRC.)
I personally lost a whole day of data at my previous gig about 4 years ago.... DPT SCSI RAID, also no longer made, yadda yadda yadda... in the long run there, I learned to use SCSI RAID controllers which keep a copy of the ARRAY information on _each_ of the drives _in_ the array, vice on the card itself. (I also learned to buy RAID controllers in pairs - it's right there in the name, Redundant - and mothball one for spare if required.)
I realize you were asking about tape - but this is almost always attached to SCSI so I threw you my two bits.
D.
On Sat, 20 Nov 2004 15:37:11 -0600, Dustin Decker dustin.decker@1on1security.com wrote:
I had a client some 7 years ago that had SCSI controller X, it shot craps, and data couldn't be recovered from drives because the firmware on the RAID controller was likewise not available, used a "funky" algorithm, etc. (Novell was part of that problem IIRC.)
This is one of two reasons I recommend disabling any hardware compression, and using software compression instead. The other, of course, is that software compression should be able to use a larger dictionary and achieve better compression (but might be a bit slower, and require some free disk space as a work area).
Of course, my job is to clean up the mess when things break, and I get to see just how spectacularly they can break.
On Saturday 20 November 2004 07:40 pm, Monty J. Harder wrote:
I had a client some 7 years ago that had SCSI controller X, it shot craps, and data couldn't be recovered from drives because the firmware on the RAID controller was likewise not available, used a "funky" algorithm, etc. (Novell was part of that problem IIRC.)
This is one of two reasons I recommend disabling any hardware compression, and using software compression instead.
Note that Dustin's account has nothing to do with hardware compression - which is reasonably consistent among different manufacturers of compatible tape drives. If the tape will mount on the drive, chances are the drive will read it, compression and all.
Software compression on the other hand, particularly if performed by a propietary program (say that three times fast), can be a guarantee of loss of data if you end up unable to run the origninal software version for some reason (lost or corrupted license key, customer support not available nights and weekends except at premium rates, etc.).
Jonathan Hutchins hutchins@tarcanfel.org wrote
I had a client some 7 years ago that had SCSI controller X, it shot craps, and data couldn't be recovered from drives because the firmware on the RAID controller was likewise not available, used a "funky" algorithm, etc. (Novell was part of that problem IIRC.)
This is one of two reasons I recommend disabling any hardware compression, and using software compression instead.
Note that Dustin's account has nothing to do with hardware compression - which
Then what "'funky' algorithm" could he be talking about? I'm not aware of an 'algorithm" for accessing SCSI devices. Sure, you need a driver that knows how to talk to the host adapter, but
is reasonably consistent among different manufacturers of compatible tape drives. If the tape will mount on the drive, chances are the drive will read it, compression and all.
When your business data are at stake, you don't want to take chances.
Software compression on the other hand, particularly if performed by a propietary program (say that three times fast), can be a guarantee of loss of
I was thinking of standard Unix compress, pkzip, gzip, which are non-proprietary. Any proprietary compression scheme, whether hardware or software, is not worth the risks - the whole point of backup is to be able to recover data after some kind of loss.
On Sunday 21 November 2004 05:00 pm, Monty J. Harder wrote:
This is one of two reasons I recommend disabling any hardware compression, and using software compression instead.
jhutchins:
Note that Dustin's account has nothing to do with hardware compression - which
mharder:
Then what "'funky' algorithm" could he be talking about? I'm not aware of an 'algorithm" for accessing SCSI devices. Sure, you need a driver that knows how to talk to the host adapter, but
RAID. His problem was an oddball RAID card that he couldn't duplicate.
"Inexpensive" RAID cards from fly-by-night hardware companies are the source of a lot of very bad experiences doccumented on the 'net.
Buying a spare when you buy the original is not a bad idea.
Buying from a supplier who controlls their manufacturing chain and guarantees backup/support is even better.
Keeping track of whether your hardware supplier is still in business and still supporting your card, and NOT KEEPING THE HARDWARE BEYOND IT'S SUPPORT CYCLE is, like, duh.
RAID is a great idea.
It can be implemented VERY BADLY.
On Saturday 20 November 2004 02:45 pm, Dave Hull wrote:
Tell me a story about tape drives.
I'm looking for any recommendations/horror stories about tape libraries and Linux.
On tape in general: http://jhutchins.blogspot.com/2004_04_01_jhutchins_archive.html
You're better off with low-cost hot-swappable HD's.
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Dave Hull -
Dustin Decker -
Jonathan Hutchins -
Monty J. Harder