HCART confussion.

[Ramiro-Magan]

Hi guys, I am chaning my LTO4 tape library for a new LTO6 one (which I am going to use with LTO4 tapes).

I will keep the old LTO4 tapes for restores, but here is the thing, I have them configured as HCART.

I was reading a post here regarding something similar and I didn´t quite got the difference between HCART, HCART2 and HCART3.

What I understood is that the type of LTO is not associated with the HCART type, so I could have LTO4 as HCART3 for example, and it wouldn´t matter.

I am going to use LTO5 tapes coz I have a remote location with LTO5 drives, and sometimes need to do cross restores.

So let´s see if I got things right.

I have the LTO4 tapes that belong to the library I am removing as HCART tapes, also the remote library has LTO4 tapes as HCART.

For the new LTO5 tapes, I should set the drives as HCART2 or 3, to set them in a different way, so if I have to do a restore from an LTO4 tape, it will go in as HCART, and all new tapes will be HCART2, so they don´t mix and try to write one of those LTO4 tapes.

Is that more or less what should happen, or did I get it all mixed up?

thanks.

[RiaanBadenhorst]

HCART, HCART2, HCART3 are just logical categorizations in NetBackup. In your case I would make the new drives HCART. If you don't you'll never be able to mount and read the LTO4 media because your new drives will be of type HCART2. So keep it all the same, just suspend the old media so its not available for writes as that would fail. Or keep them in standalone.

[Marianne · Accepted solution]

I would keep the different drive types and media as different densities - LTO5 tapes and drives as HCART2. To restore LTO4 tape, change one LTO5 drive to HCART for the duration of the restore.

[mph999 · Accepted solution]

The 'densities' have no technical meaning, think of them as colours.

hcart = green

hcart2 = blue

4mm = yellow

The rule is, a tape will only be allowed to go into a drive that is the same colour

So a green tape will only go into a green drive

Likewise

A hcart2 tape will only be allowed to go into a hcart2 drive

The one exception is qcart - this must never be used (unless you had a qcart drive) as it causes NBU to write in fixed 512k block, which will cause failures on non qcart drives.

[Ramiro-Magan]

Excelent, that clarified it all. I googled it and there was nothing that was really clear.