Virtual tape library

[jykirsc]

We're going to add a fibre attached virtual tape library (EMC EDL 4200) to our TSM ( v 535) environment. We have 150+ clients distributed between 2 TSM instances. Is it possible for each TSM instance to own half of the VTL, or does 1 TSM instance have to be the master, and the 2nd the slave? We would like to do as little volume reclamation as possible. What's the best way to set up virtual libraries , virtual tape drives and storage pools to accomplish this? Thanks.

 

[sgabriel62]

Big questions -= small answer - In my experience - this VTL of your will be able to handle both instances very easily - dependent upon how large your VTL is.
No masters or slaves needed - simply "share" the library emulation of choice between the TSM server instances. I did mention the Tape Library emulation - Be cautious - DO NOT USE EMC'S default - TSM is very unhappy with it. Best option choices - IBM 3584 or an ADIC. Both will offer you the largest amount of tape drives and tape slots.

Read your manuals carefully - do not use expand on demand until you're quit happy with your VTL.

Good luck - let us know how things turn out

 

[jykirsc]

Steven,

Thank you for the information. I'll post about the implementation.

 

[jeddy]

While you can leave the TSM servers configured independently and sharing a single virtual library, that does leave you at risk for robot/tape contention. If both servers attempt to control the virtual robot or access the same tape at the same time, there is a slight chance that you could get unexpected results. This is exactly like a single physical library would act if you tried to share it between independently-acting backup servers.

You have two choices that I can think of:
1) Set up the backup software such that multiple servers can intelligently share a single library. This may be the "slave" configuration that you describe.

2) Create a virtual library for each backup server with its own set of tapes so that there is no chance of contention.

Your best bet is to consult with your EMC support or implementer contacts

 

[sgabriel62]

jeddy
I disagree with your assumption. First VTL is "disk" there will not be any "robot" contention. Also keep in mind - even in a physical "shared" library environment - each TSM server will assign ownerships to the media its have requested or put into use. There will be no way TSM will allow two servers to use the same media.
The only contention will be of the array backplane.

 

[may]

agree with Steven,
you can share your physical library without problem, the share got to be configured on your Library (for example it's pretty easy on a 3584 (TS3500) just need a barecode ont the top to separet / assign a logical library)