Forum Discussion

ryanlee's avatar
ryanlee
Level 2
11 years ago

Hcart Issue

Hi,

We had 1 tape library with 1 LTO4 tape drive (using LTO4 tapes) and media type is displayed as hcart

We have just recently purchased a second tape library (we were going to just add a drive but we got a great deal on a new library)

So we now have a second tape library with 2 LTO5 drives (using LTO4 tapes) and they display as hcart2

 

Both storage units are in a storage unit group that we use for all backups.

We plan to eventually move to LTO5 tapes but for the moment we want all drives to use LTO4

So some of our tapes now read hcart and hcart2 is this going to cause us problems?

I've also just noticed that some tapes in one of the library's have split off into different volume groups despite being in the same library so this has made me think my understanding of hcart was wrong.

 

Thank you

  • hcart/hcart2 are just labels. 

    If you have hcart2 drives and no hcart drives, you will not be able to use the hcart tapes.

    Also you need to ensure your stu is set correctly too.

     

5 Replies

  • hcart/hcart2 are just labels. 

    If you have hcart2 drives and no hcart drives, you will not be able to use the hcart tapes.

    Also you need to ensure your stu is set correctly too.

     

  • So a tape library that is hcart2 cannot use a hcart tape?

     

    This would cause a problem as we have have two libraries sharing tapes.

    Can I change it so both read as hcart?

     

  • Yep, you can change it under devices > drives, change the drive properties. Might need to restart ltid. Not sure exactly about the vol group bit unless you post up the vol groups here ... Perhaps this will help vol groups are a logical representation of location. XX_YYY_tld for example XX is the library number, so two tld libraries would cause x2 vol groups 00_000_TLD 01_000_TLD The confusing bit it the middle number, it is a instance number of drive density, that is, how many different density drives there are but not what they are If we take library 1 with hcart drives 00_000_TLD Then add hcart2 drives (or redefine some of the existing drives as hcart2), we get a new vol group 00_001_TLD (and the hcart2 tapes would go into this group) Add some hcart3 drives 00_002_TLD and so on As revaroo says, the actual drive density is just a label, it has no technical meaning. It would be much easier if colours were used A red tape can only go into a red drive Then there would be no argument that a different density affects tape performance and capacity, which it does not. You can define your LTO5 drives as 4mm, they will work exactly the same.
  • If you searh for "hcart" in the "ideas" section there have been several proposals to have NetBackup recognize media types instead of using these labels.  (e.g. recognize that an LTO6 drive can read but not write to LTO4 tapes)   I've voted thumbs-up for these suggestions!