Tapes are not completely filled

[pkelly_sts]

No this is HP MSL2024 with LTO-6 & latest f/w & drivers.

[Shestakov]

Thanks for the reply.
Could you contact Veeam technical support for logs review to investigate the real issue why the tape has 100GB left?
Once you do, please post support case number for us to chime in if needed.

[pkelly_sts]

Thanks. Now logged as case #01844888

[Shestakov]

Update.
It turned out that 100GB is HP`s EOM (end of media), so VBR behavior is expected.
Thanks!

[pkelly_sts]

Ah, ok, how kind of HP to waste our tape! Oh well, thanks for confirmation..

[Shestakov]

You are welcome.
They probably did it for a purpose. Usually quality of the tape itself is worse closer to the end, so data integrity may not be guaranteed by the vendor.
But you better ask HP.
Thanks!

[Didi7]

Hello everybody,

since a couple of weeks, we have one VBR 9.0.0.1491 backup system, which serves as a backup System for 2 different customers. Both customers have 11 VMs in their B2D-jobs, which result in the following deduplicated disk-usage-capacity in the customer's respective backup-repository ...

Customer A = 4.63TB used capacity in Customer's A backup repository
Customer B = 2.51TB used capacity in Customer's B backup repository

VBR 9.0.0.1491 works like a charm, the only thing I would like to discuss, is the fact, that VBR doesn't seem to use the full capacity of an LTO6 tape media, see here ...

Customer A:



As you can see here, lots of space is unused on LTO6 tape media?

Also Customer B uses 2 LTO6 tape media. Ok, in the meantime 2.51TB is used, so that 2 LTO6 tape medias would be necessary anyway, because the deduplicated B2D data is already compressed and we don't compress data on tape again.

What's the reason?

Regards,
Didi7

[veremin]

We rely on information coming directly from a device. The device instructs us to stop appending data to a particular media, whenever it finds it necessary. Thanks.

[Didi7]

We rely on information coming directly from a device. The device instructs us to stop appending data to a particular media, whenever it finds it necessary. Thanks.

Unbelievable! HP propagates the net capacity of an LTO6 tape media is 2.4TB but in reality it is only 2.3TB !!!

I have a Déjà-vu! Harddrive capacity?

Well, at least, it is an explanation, why the full propagated capacity of a 2.4TB LTO6 tape media cannot be fully occupied.

Regards,
Didi7

[Didi7]

Really funny, that Symantec Backup Exec can successfully hide the fact, that the full capacity of the propagated net capacity cannot be used. I first stumbled about that in VBR!

I never used LTO7 tape media so far, but if 3-5% are left unused, this could mean up to 312GB wasted!

Funny!

[tecserve]

According to support there is a known bug in the latest v9.5u4 that screws up space distribution, even when you disabled new media set creation - I have pools with a mix of LTO8 and M8, over 80TB of space, and 40-50TB free and it keeps asking for new tape halfway into a 4-5TB archive job... maddening.

[Dima P.]

tecserve,

Can you please share you case ID with us for a review? Thanks!

[tecserve]

Hi, yes, it's #03423644 - thank you!

[wendellmoine]

I have 2 libraries assigned to VEEAM, both are HP MSL 4048 (one is LTO5 and other is LTO6). I am using simple medial pools with 'Do not create, always continue using current media set' option selected.
VEEAM is leaving anywhere from 3 to 100+ GB free on all tapes. I have dozens of tapes that have just a little space left, but none are completely full. I have parallel processing enabled. Is this normal? And if so how do I know when to pull the tapes?

[Dima P.]

Hello and welcome to the community wendellmoine.

I've merged your post to existing discussion. To cut the long story short end of media (the value when Veeam B&R should stop writing data to the specific tape) is reposed by the device it self based on the tape media chip information. When Veeam B&R receives this information - tape is treated as full. Cheers!

[wendellmoine]

OK, but why is VEEAM not marking the tape as full then? We previously used these libraries with Networker and they would be marked as full. Didn't make any configuration changes when I moved them to VEEAM.

[Dima P.]

Sounds like a perfect idea and I'll discuss it with the RnD folks. Thanks for sharing!

[Dav3Mc1]

Following post. Seem to have a customer with a similar issue with a new tape being used from the pool, where there is plenty of space left on the existing tape.

[cam99x]

I have this as well. New job 3 new tapes and each has been left with free space 7.3Gb, 23.4gb, 828gb. I have management asking me why we need so many tapes. Since this is going to be removed I had better log a job.

[Dima P.]

Campbell,

Can you please also clarify if these are new brand new tapes? Additionally please check via vendor's tools that mentioned tapes do not have any third part partitions? Thanks!

[cam99x]

These are new tapes from HP unwrapped never used before.

I logged a ticket 04093049. Because I though this would be removed.

"The amount of free space left on tape media depends on tape device vendor and possibly model, but typically should be about 3-5% of total capacity. You will need to check with the vendor if you need the details."

The results above don't look like a standard 3-5%.

[Dima P.]

Campbell,

Thanks, I've asked RnD folks to take a look at your case details.

[cam99x]

Thanks for getting RnD to have a look at the problem. The tape job I submitted logs for was very small. Out monthly tape job can be 20-30 tapes. This will make a big difference for it if the tapes could be filled to capacity.

[Dima P.]

Campbell,

The idea from QA team was that the tape drive might not correctly report the size of the tape. Can you please check if the tape drive requires cleaning or not? Thank you in advance!

[cam99x]

The tape drive does not require cleaning.

[lyapkost]

Hi Campbell.

7.3Gb, 23.4gb, 828gb

The results above don't look like a standard 3-5%.

3-5% of 1.4 Tb (LTO5) is 42-70 Gb. So it looks ok for the first and the second tapes, isn't it? Regarding the third one I assume it is not filled yet and some data may be appended. You may check it by running a job to this media pool (make sure you have setting 'Do not create, always continue using current media set' in media pool settings on 'Media set' step).

[cam99x]

Hi Iyapkost

I checked the media set and the option from "Automatically create new media set" is set to "Do not create , Always continue using current media set".
I was asking about the tapes in this media set because I had created it fresh and used all new tapes. HP LTO5 straight out of the box.

One of my other tape jobs is like this

Tape 4 in a sequence of 13 tapes has 1.2TB free on a 1.4TB tape.

The tapes on either side have differing amounts of free space.

I uploaded the image to
https://imgur.com/gjuxAgU
https://imgur.com/gjuxAgU

There was 20 used tapes in this job and 10 new ones. So I was expecting the new tapes to have the same amount of free space left.
We have a 4 slot/bay tape changer that this job takes about 4 days to finish on.

Does this happen to everyone or do I have an problem?

I have inherited a relatively complex system that I am trying to figure out.

[lyapkost]

Hi.

The tape with 1.2 Gb left (MMAR23) is the last tape in it's media set (#128). Sort tapes by Media set column and you'll see it. The last tape in each media set is always not completely filled. If you want to figure out the reason why media sets were closed please keep working with support. The same story with tapes MMAR22 (last in media set #129), MMAR24 (#126), MMAR19 (#127). Amount of free space left on other tapes is slightly different, it's ok, and it doesn't exceed the 3-5% mentioned above. So I see there no problem at all.

You can learn more about media sets here.

[cam99x]

Thanks, Iyapkost

this is a URL that talks about parallel processing
https://helpcenter.veeam.com/docs/backu ... ml?ver=100
Supplied by support.

"a media set is opened per each drive" is the reason I have so many sessions. It's a new session per drive used when parallel processing. It's set to use all of the 4 drives I have in the autoloader.
If I turned off the parallel processing it would be more tape efficient because there would only be one session, so one last tape. It would be time inefficient because it would take 4 times as long to write the data out.