storage unit density

[zoan_nbu]

Hi All,

i have a robot with 3 different tape drives types.

now i neeed to configure it in NBU.

i know that density must match between st unit,media and drive.

I have configured robot and under storage device column in storage unit tab,it is showing dlt2.

My query is how to configure storage unit with different density as st unit type cannot be changed.

NBU 7.1

LINUX

[Nicolai]

You configure a storage unit per denisty type. 

http://www.symantec.com/docs/TECH155073

http://www.symantec.com/docs/HOWTO34522

If in doubt use the "storage unit configuration wizard". I will take diffrent densities into account.

[zoan_nbu]

thanks nicolai.but storage unit is only configured once.

i have 3 drive types in  my library and storage device is showing dlt2.

what are the steps?

[mph999 · Accepted solution]

When you configure the STU, you select the density of the drivees it will point at.  If you had x2 diff density drives, you sould have a choice, eg hcart or hcart2

If your stu is showing dlt type, then I suspect if you look at the drives, they have been configured as dlt.

It can be left, the density itype has no effect on performance or capacity, as long as the density of the tapes match the drives it will work.

If you wish to change it, reconfigure the drives as the density you want (can be changed under devices if you right click the drive and select I think properties.  Once drives have been changed, restart ltid on all media servers and then reconfigure a new STU and choose the new density.

[Marianne]

i have 3 drive types in  my library and storage device is showing dlt2.

Three different drives types should have 3 different densities - not all the same.

Did you use the device config wizard to add devices to NBU?

If you did, NBU would use built-in defaults to assign different densities to drive types, e.g:
LTO1 - > hcart
LTO2 - > hcart2
LTO3 - > hcart3
LTO4 - > hcart
LTO5 - > hcart2
LTO6 - > hcart3
 

So, it all depends on what type of tape drives you have in your environment - if you have LTO2 and LTO5 drives in the same library, you will have to manually change the density for one of them and manually add Storage Unit to match. 
Please remember that media type must match density type.

Please show us output of the following commands to get a better understanding of your environment:

/usr/openv/volmgr/bin/scan

/usr/openv/volmgr/bin/tpconfig -l

[zoan_nbu]

thanks both.

so storage unit density has no impact.?am i correct?

media and drive density must match.

[mph999]

Well, STU density needs to match the drive type, which needs to match the media type ...

In terms of performance/ capacity, it has no effect.

[zoan_nbu]

@Marrianne:

st unit is hcart3.

So, it all depends on what type of tape drives you have in your environment - if you have LTO2 and LTO5 drives in the same library, you will have to manually change the density for one of them and manually add Storage Unit to match.

drive 1:hcart2

drive 2 :hcart3

so i have to make  both my drive density to either hcart2 or both as hcart 3.and then match with tapes.

Am i correct?

[mph999]

Yes - think of it like colours ...

A red tape only goes in a red drive and a red STU uses the red drives, which require red tapes.