VTL - estimated capacity of tapes?

[lapfrank]

Hi All,

something I just noticed about the estimated capacity of the tapes on TSM from my VTL..

On the VTL, I defined 100 gigs as the size of the cartridges.
On TSM, I have a device class for my VTL (ProtecTIER) and I didn't define any estimated capacity (left it empty).
Now, when the VTL tapes are filling, they show as "762.9GB" in estimated size... but when they're full, they show as 100GB. Anyone know why that is ?

To fix it, I just updated the estimated capacity on the device class to 100 GB, but I was wondering if that was the best way to go, as I would need to manually update it depending on my factoring ratio.. Where's that 762.9GB coming from ?

Thanks a lot!

 

[Jeff_Jeske]

TSM only knows about what it sent to the device..... if you are using hardward dedup or compression the numbers will not align with the what TSM thinks it can stick on a volume.

 

[lapfrank]

yep, I understand that, which is fine. The number is 100 gigs. The cartridge size is based on the post factoring ratio which is about 5:1 in my case. So from what I understand, I do need to update the estimated cap on the devclass if I want the numbers to align to what is nominally stored on the cartridge.

Thanks!