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LTO 6 space occupying issue.

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Hari Krishna Pune
LTO 6 space occupying issue.
on Jul 31, 2018 at 7:55:03 am

I have been using the IBM TS2260 3580 H6S HH Drive from 2014. From last week I am getting an issue with the space in the tape media. While I am copying data to LTO 6 media I am getting a message saying that there is no space left after copied around 1.5tb sometimes, 1.2tb sometimes. The properties of the copied data showing right amount but, properties of the tape showing full. I usually work on mac os x. Tried with mac os x and windows 10 also. Yesterday I have also run the ITDT health test. But performance showing error, remaining everything passed. I never used any backup application. Going through the terminal commands from the beginning itself. Tried replacing the cable also. But no luck. Any solutions?

HARI KRISHNA PUNE
FCP EDITOR & ARCHIVE MANAGER


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Jerzy Zbyslaw
Re: LTO 6 space occupying issue.
on Jul 31, 2018 at 11:44:58 am

The LTO specification requires that after a write is done then immediately following that the read heads read the data back and check if it is written properly and if not the data is written out again and a "soft error" is recorded and this process can repeat up to 16 TIMES before it gives up and records a "hard error" so the data may be eventually successfully written but there could be a lot of bad writes taking up a lot of space in between and as long as this is <16 then you probably would not notice there's a problem until you notice that you can only write significantly less data to the tape itself like you mentioned.

I suggest you check the soft error numbers as you could have millions or billions of them and if you do then this usually indicates that you have dirty heads that need cleaning or worn out heads that need replacing, however, since the tape heads reputedly cost around a quarter of the cost of a new tape drive it is not really cost effective to repair it with replacement heads and you may as well buy another tape drive. If this is not the cause of the problem then I don't know what else it could be as the LTO tapes have servo tracks on them to make sure that the heads are positioned on the actual tape track correctly.


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Hari Krishna Pune
Re: LTO 6 space occupying issue.
on Aug 1, 2018 at 2:00:21 am

@Jerzy Zbyslaw
Thanks for your quick reply. I am not a professional to understand the coding language. Forgive my ignorance and please explain check soft error numbers. Thank you.

HARI KRISHNA PUNE
FCP EDITOR & ARCHIVE MANAGER


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Jerzy Zbyslaw
Re: LTO 6 space occupying issue.
on Aug 1, 2018 at 8:19:53 pm

Hello, usually the backup software will tell you as part of the log of data written to the tape as to how many soft and hard errors have occurred and here is an example for Backup Exec https://www.veritas.com/support/en_US/article.100020857 notice that it only has 857 soft errors which is a low amount and can be disregarded.

Since you mentioned that you are using an IBM tape drive then what you should do is download the IBM tape diagnostic tool and see what information you can obtain from that, you can download it here https://www.ibm.com/support/knowledgecenter/en/ST9MBR_1.2.5/ltfs_itdt_downl...

There is always the possibility that there is nothing wrong with the tape drive unit itself and it may be the tape in the cartridge that is the source of the problem especially if it is old and has been re-used many times but this is easy to check because if you then use a new tape cartridge it should store close to the full amount possible so check this as well that your old tapes are not worn out, if the tape heads are the problem then it will store like you said "1.5tb sometimes, 1.2tb sometimes" on both old and new tapes.

Either the tape heads need cleaning and haven't been cleaned for a while in which case you will need to clean them with a cleaning cartridge or they are going bad and here is a previous discussion with similar problems that you had and it was diagnosed that in that particular case the tape heads were actually bad https://forums.creativecow.net/docs/forums/post.php?forumid=330&postid=654&... What is the cause with your situation I do not know, it could be any of these problems.

Cheers


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Hari Krishna Pune
Re: LTO 6 space occupying issue.
on Aug 2, 2018 at 7:37:45 am

Hi, Thanks for your explanation. Yeah you are right, If I am using an backup application I may know about the soft errors. But in my case I am not using one.

I ran the health test & full write test using IBM tape diagnostic tool a while back. Please see the attached images for the test results. I ran the test multiple time by changing the drive firmware also. Still stuck with Performance failed message.

As you said it might be the issue with the tape - for that I am not using any old tapes here in this case. All the tapes are brand new. Also providing the consistency check and rollback pics. Please refer.

And in the matter of cleaning head I never did it on purpose, But I did it when ever my drive shows an error code "C" in the single character display. After got this issue I have seen an post from another blog and tried to hard clean with multiple times. Still getting the same issue. Yesterday I tried running cleaning cartridge for up to 10times and then make some data transfer. And the result is I have copied the data of 1.1TB and is showing that 1.35TB occupied in the tape.

HARI KRISHNA PUNE
FCP EDITOR & ARCHIVE MANAGER


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Jerzy Zbyslaw
Re: LTO 6 space occupying issue.
on Aug 2, 2018 at 7:10:43 pm

Unfortunately, I have no idea what is wrong with the drive and at this point I can only suggest that you first post your last reply on the public IBM forum and see if someone else can diagnose the issue https://www.ibm.com/developerworks/community/forums/html/topic?id=1eac1dfe-... or alternatively contact IBM support directly https://www.ibm.com/support/home/product/5301452/Tape_Drive


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Hari Krishna Pune
Re: LTO 6 space occupying issue.
on Aug 2, 2018 at 7:47:11 pm

@Jerzy Zbyslaw
Thanks for the suggestion. I will follow the path and let's try.

HARI KRISHNA PUNE
FCP EDITOR & ARCHIVE MANAGER


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Hari Krishna Pune
Re: LTO 6 space occupying issue.
on Aug 4, 2018 at 6:17:46 am

I forgot one thing to mention. So bad. At first I started to notice some line in the terminal window while I format a tape. While formatting the tape at the bottomline of "writing index to a", "writing index to b" I noticed a line saying "failed to release the advisory block". Have any one seen this before?

HARI KRISHNA PUNE
FCP EDITOR & ARCHIVE MANAGER


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Neil Sadwelkar
Re: LTO 6 space occupying issue.
on Aug 6, 2018 at 9:51:12 am

Are you writing to tape as LTFS?
Are you doing drag and drop (or copy-paste) in Win Explorer?
Or do you use some software to write to tape?

Your signature says 'FCP Editor'. So maybe you're backing up Mac drives via a Windows machine?

-----------------------------------
Neil Sadwelkar
neilsadwelkar.blogspot.com
twitter: fcpguru
FCP Editor, Edit systems consultant
Mumbai India


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Hari Krishna Pune
Re: LTO 6 space occupying issue.
on Aug 6, 2018 at 9:56:10 am

@Neil Sadwelkar

Thanks for your concern. Yes, I am writing to tape as LTFS. And I am doing copy-paste in windows explorer. I am not using any software.

I am an FCP EDITOR. I have tried this with both mac and windows.

HARI KRISHNA PUNE
FCP EDITOR & ARCHIVE MANAGER


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Tim Gerhard
Re: LTO 6 space occupying issue.
on Aug 10, 2018 at 6:30:39 pm

We repair and refurb tape drives all day long at Magnext / MagStor.

I saw that you mentioned running a cleaning cartridge 10x times in a row. This is a big time no-no and can kill your drive head. Only clean when the light is on.

If you're failing performance tests with good media, then your head is is usually going bad.

The way LTFS works, it can never give you an accurate capacity of the tape because each file you copy over writes a separate marker file.

Tim Gerhard
MagStor Inc.
614-505-6333
tgerhard@magnext.com
NAB 2018 Booth #SL15816


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Hari Krishna Pune
Re: LTO 6 space occupying issue.
on Aug 11, 2018 at 9:57:17 am

@Tim Gerhard

I took that advice to clean the drive multiple times from the below link or else I couldn't have done that.
https://serverfault.com/questions/857771/what-could-cause-an-lto-drive-to-w...

You people are so lucky coz you have so many guys there who can provide service for such kind of drives. But I am sitting in India. Couldn't find one useful. Found two guys who doesn't even tested the drive, but through the symptoms I have shared they said the head is gone. But I still can still read and write the tapes. I tried to reach IBM for its service. But they said the drive is out of warranty, so they can provide paid service. But they wanted me to pay 35% of the drive cost for the "initial onsite assessment to obtain problem" and the service charges would be vary as per the issue. I don't know if it can be solved or not? I didn't replied them yet to confirm the service.

I am just trying to figure it out through the Setup, Operater & Service Guide I got when I purchased the drive.
I couldn't connect to http://169.254.0.3 through the Ethernet service port they provided in the rear.
So I tried maintenance mode with code "1". Result is good. No errors found by the end of the test.
Then I tried code "H" to check for head errors. But I found nothing test is done in 120 minutes like they mentioned in the manual and went back to the normal status.

Planning to run code "F" to check the write performance test. Let's see the results.

HARI KRISHNA PUNE
FCP EDITOR & ARCHIVE MANAGER


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Hari Krishna Pune
Re: LTO 6 space occupying issue.
on Aug 13, 2018 at 7:13:52 am

@Jerzy Zbyslaw, @Neil Sadwelkar, @Tim Gerhard

I Thank you for all your suggestions. I think I have overcome with the issue.

After enter to the maintenance mode as I said earlier I first run the drive diagnosis code "1" and test head code "H".

And then run code "6" - Host interface wrap test by connecting to the sas port 1 and the result turned with error code "8", Then I checked again by connecting to port 2 then the result is good.

Hope the sas port 1 has issues. Then I run code "F" to check performance. I got error with the error code "A" even I connected the drive to sas port 2. I tried it twice but got the same error.

So I went out of the maintenance mode and put a copy to test with a data of 300gb red raw footage. It just occupies the same 300gb. But the speed is low it seems, It took one hour to copy 300gb.

First thing I have issue with space. So that has been solved. I am going to check with a full tape. After it's done. I will get back to the forum with the results. Let's hope everything good.

Thanks once again to every one of you.

HARI KRISHNA PUNE
FCP EDITOR & ARCHIVE MANAGER


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Tim Gerhard
Re: LTO 6 space occupying issue.
on Aug 13, 2018 at 8:29:20 pm

I actually take back about the head, even though it's still possible. When you fail performance from "unexpected data" this is an error code that can mean several different things.

Reduced capacity can be from a head, but just not sure without seeing the drive in person.

Tim Gerhard
MagStor Inc.
614-505-6333
tgerhard@magnext.com
NAB 2018 Booth #SL15816


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Hari Krishna Pune
Re: LTO 6 space occupying issue.
on Aug 14, 2018 at 5:17:02 am

@ Tim Gerhard

Thank you for your concern. I can understand without seeing the drive one can not estimate the issue.

As I am checking from yesterday I am getting multiple results with multiple tapes.

The first test I did is with a used tape, I copied the data of 400gb to it and didn't occupied any extra space. Thought it solved.
The next test I did with a new tape. I copied the data of 2TB and the tape is filled. Only 4gb space is left. It's just better than 1.5TB.
Later I did another test with another tape I can able to copy up to 2.31TB and another 100GB space left. It's cool actually. But its taking around 10 hours to finish a tape writing. I still don't know whether the problem exist or not. Just doing some more tests continuously.
Yesterday I have also run the performance test using code "F" in the drive again. Still has the same error.
As I am writing data to tape I am getting a weird noise like iron squeaking from the drive.

I will post the latest results as well.

HARI KRISHNA PUNE
FCP EDITOR & ARCHIVE MANAGER


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Neil Sadwelkar
Re: LTO 6 space occupying issue.
on Aug 14, 2018 at 4:32:34 pm

Just a thought.
Since you have a Mac system handy, why don't you download a 30 day trial of software like Bru-PE or Yoyotta (both Mac only) and write the tape using these. Both these softwares have reporting and logging so you can then involve them in the troubleshooting. Even if there is a hardware issue, the logs will reveal that. Your SAS card should work in the Mac with drivers.

At the moment you're on your own since IBM has disowned you (very common in India) since you're out of warranty. And you're doing a drag and drop copy to LTO which means you're at the mercy of Windows.

In the long term using some dedicated software to write to LTO tapes is a more robust and stress free activity than staying late at the office struggling with these issues.

Also, as a point of info, (not that it matters in your case), but here in India I've found, Tandberg support is much better even years after the warranty expires. They have a guy here who knows his stuff and the company gets fully involved in finding a solution.

-----------------------------------
Neil Sadwelkar
neilsadwelkar.blogspot.com
twitter: fcpguru
FCP Editor, Edit systems consultant
Mumbai India


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Hari Krishna Pune
Re: LTO 6 space occupying issue.
on Aug 15, 2018 at 9:40:22 am

@ Neil Sadwelkar

Thank you very much for you suggestion. I will try using the trial version of the applications. And yes I am connecting the drive to mac using Atto R680 with the latest driver available. I will also consider fcpguru from mumbai. I will ask his support too. Thank you.

HARI KRISHNA PUNE
FCP EDITOR & ARCHIVE MANAGER


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Hari Krishna Pune
Re: LTO 6 space occupying issue.
on Aug 16, 2018 at 6:23:55 am

@Neil Sadwelkar

Hi All,

Last night I have put a backup using BRU-PE. By the end I see no errors in the report. Please have a look at the report.



Thank you.

HARI KRISHNA PUNE
FCP EDITOR & ARCHIVE MANAGER


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Hari Krishna Pune
Re: LTO 6 space occupying issue.
on Aug 16, 2018 at 7:48:40 am

Hi all,

Can anybody tell me how to checkstatus, enable/disable lossless hardware compression using terminal in mac os x 10.13?

HARI KRISHNA PUNE
FCP EDITOR & ARCHIVE MANAGER


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