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HP LTO 6250 problem with recover data LTFS

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Mateusz Malina
HP LTO 6250 problem with recover data LTFS
on Jul 10, 2015 at 10:20:37 am

Hi all,
I have HP LTO 6250 Ultrium and I'm working with LTFS. Just copy video and dpx/exr materials over to lto tapes using total commander, and verify md5 checksums. For ltfs formating and troubleshooting I'm using HP store open.
I needed to restore some materials and I found big problem. I started copying some DPX files from tape to server and after every few hundred frames copying crashes and ultrium drive starts rewinding tape in search for file but never finds it.
It looks like tape has been degraded or corrupted but I found this problem with few tapes (different brands [HP and IBM] - all LTO 6 not sure about lto5).

Does anyone has similar problem or any suggestions?


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Tom Goldberg
Re: HP LTO 6250 problem with recover data LTFS
on Jul 11, 2015 at 3:30:43 pm

As I wrote to a previous poster in this forum just a week ago:

[Tom Goldberg] "The Quantum (and the IBM and the HP) LFTS software will work OK for archiving. You will quickly find that when it comes time for restoring, these solutions are not up to the job for more than 1 or 2 files at a time. This is because they are not smart enough to pre-sort restore requests for tape order and thus will zig zag all over the tape to recover each file and can take literally days for any large number of file restores"

With DPX files, the situation is compounded since you are not dealing with big old video files but many thousands of tiny individual frame files. You are going to have to purchase someone's solution that pre-sorts - examples include PreRoll Post or YoYotta for software only or Cache-A or Storage DNA for complete solutions.

Tom Goldberg
TGCS
30201 Rainbow Hill Rd.
Evergreen, CO 80439
mailto:tomgoldberg@gmail.com
http://tomgoldberg.net




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Mateusz Malina
Re: HP LTO 6250 problem with recover data LTFS
on Jul 13, 2015 at 9:48:39 am

I sort files before copying and restoring many files don't take so much time to copy from LTO to server, until it runs into one file, where it crashes and zig zag all over the tape searching this one frame. It can takes many hours without any result.

000:26:44.31 74/666 0x508f PP_EXPECTED_DATASET_NOT_FOUND (Cannot find expected Data Set Number) ET3HT44V23


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Mateusz Malina
Re: HP LTO 6250 problem with recover data LTFS
on Jul 15, 2015 at 10:06:01 am

Sorry for spam, but I have to restore all this file as soon as it possible. HP support don't have any idea how to fix this problem. The strangest thing is that after archiving files, I checked md5 file on tape and it ended correctly without any errors. Now, after few months with no using this tape, device can't find crashes files and checksums show errors on them.
Any solutions how to fix this problem? I know that I should change workflow and buy some dedicated software like BRU, but for now I need to restore all this files in a few days..

Cheers


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Tom Goldberg
Re: HP LTO 6250 problem with recover data LTFS
on Jul 15, 2015 at 2:53:02 pm

If you are getting errors on restores beyond your original error of not being able to find files, you may be experiencing tape drive problems. Have you tried running a cleaning tape?

If that doesn't work, I'd recommend you find someone with a Cache-A or a copy of Pre-Roll Post or YoYotta to see if they can read the tape. BTW, BRU doesn't do LTFS.

Tom Goldberg
TGCS
30201 Rainbow Hill Rd.
Evergreen, CO 80439
mailto:tomgoldberg@gmail.com
http://tomgoldberg.net




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Tim Jones
Re: HP LTO 6250 problem with recover data LTFS
on Jul 15, 2015 at 4:10:15 pm

... and this is a perfect example of why TOLIS Group solutions - as Tom says - "DOESN'T do LTFS." It's unpredictable at best, fails when you need it most at worst, and no one provides a responsible level of support.

As far as what you're running into, I'm pretty certain that the other guys won't be able to get around that one as it's an LTFS format level error.

Tim
--
Tim Jones
CTO - TOLIS Group, Inc.
http://www.tolisgroup.com
BRU ... because it's the RESTORE that matters!


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Tom Goldberg
Re: HP LTO 6250 problem with recover data LTFS
on Jul 15, 2015 at 7:56:39 pm

[Tim Jones] "[LTFS is] unpredictable at best, fails when you need it most at worst, and no one provides a responsible level of support" True that you won't get much support from HP for their freeware but...

I'm pretty sure that there are many who would not agree with this statement - like for instance, the Discovery Network who has standardized on LFTS for their submission format. Or, any of the many vendors who build LTFS into their products and provide their own support services (including the likes of YoYotta, Imagine's Pre-Roll Post, ProMAX Cache-A, StorageDNA, XenData, SGL, and no doubt others). Not only have these vendors and Discovery found it to be reliable, but it is also proving to be an effective interchange standard allowing any of these companies to read their competitor's tapes.

Tom Goldberg
TGCS
30201 Rainbow Hill Rd.
Evergreen, CO 80439
mailto:tomgoldberg@gmail.com
http://tomgoldberg.net




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Tim Jones
Re: HP LTO 6250 problem with recover data LTFS
on Jul 15, 2015 at 9:02:59 pm

Hmmm, funny that you should mention Discovery since the number one complaint at the Discovery help desk - according to none other than Josh Derby in front of witnesses at the SMPTE conference - is that many submitted tapes can't be mounted and must be resubmitted by the production teams.

And I'm certain that the Mateusz agrees that LTFS is truly reliable in light of the post that started this thread.

Sorry if this sounds like sour grapes, folks, but the job of any tape backup / archival solution is to restore the data that is supposedly written onto the tape. I get very frustrated by vendors that ONLY have LTFS as a tape option promoting LTFS as a robust and trustworthy solution while the users (who actually matter) are calling us every day looking for a replacement for a failing LTFS install.

All I can do is offer our solutions to those of you looking for LTO storage with the commitment that you will get proper support from our team members and that you will be able to restore your tape-based data tomorrow and in 20 years.

Tim
--
Tim Jones
CTO - TOLIS Group, Inc.
http://www.tolisgroup.com
BRU ... because it's the RESTORE that matters!


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Mateusz Malina
Re: HP LTO 6250 problem with recover data LTFS
on Jul 24, 2015 at 2:03:36 pm
Last Edited By Mateusz Malina on Jul 24, 2015 at 2:35:47 pm

I agree with Tom about LTFS reliability..but it just happened and I've big problem because I worked on the open source HP software on LTFS and right now I received last message from HP support that they don't see any bugs and problems from their hardware or software and support application was closed.

I checked these tapes on the Cashe-A hardware and software, but without any positive results. Copying crashes on this same files in this same moment. I know that we have to change our workflow, but I would like to recover all these 'crashed' files.
Do you know any software for deep recovery for LTO-6 on Windows or Linux (our SAS controller is not compatible with OS X). I checked ltfsck, but result was that media are consistency and it didn't solve problem.
Or maybe some software which, can dump all files from tape, without indexing?


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Tom Goldberg
Re: HP LTO 6250 problem with recover data LTFS
on Jul 24, 2015 at 2:39:27 pm

That's really too bad Mateusz - it sounds like just those files are damaged and were most likely bad on the source device or corrupted during the transfer to the tape drive. IMO, it is unlikely that they are bad due to LTFS or LTO issues.

Unfortunately I have no suggestions other than possibly data recovery services* - maybe Tim has a better idea.

Articles about 2 LTO data recovery experts:
http://www.storagenewsletter.com/rubriques/tapes/data-recovery-services-cor...
http://www.storagenewsletter.com/rubriques/security/kroll-ontrack-perform-d...

Tom Goldberg
TGCS
30201 Rainbow Hill Rd.
Evergreen, CO 80439
mailto:tomgoldberg@gmail.com
http://tomgoldberg.net




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