ADSM-L

Re: [ADSM-L] UN-mixing LTO-4 and LTO-5

2012-06-12 23:51:23
Subject: Re: [ADSM-L] UN-mixing LTO-4 and LTO-5
From: "Prather, Wanda" <Wanda.Prather AT ICFI DOT COM>
To: ADSM-L AT VM.MARIST DOT EDU
Date: Wed, 13 Jun 2012 03:44:53 +0000
Hi Roger,
I've done this many times (creating 2 logical libraries in 1 physical) to 
separate LTO types at various customers.
I don't know anything dangerous about it.  (Granted, I've never tried to have 
the 2 logical libraries run a CHECKIN at EXACTLY the same time, but I don't see 
that as being a likely occurrence.)

If you do a search=yes (or search =bulk) with no other parms, then yes indeed, 
the checkin for that logical library will grab all the tapes that are available 
for checkin. 

However, if you have nicely arranged numeric volsers (see the manual for 
requirements, alpha prefix and alpha suffix are allowed), you can use VOLRANGE 
and automate everything.

For example, you can throw a mixture of carts into the bulk I/O door, then run

CHECKIN LIBV SCSILIB4 SEARCH=BULK CHECKLABEL=BARCODE VOLRANGE=XXX000L4,XXX999L4 
CHECKIN LIBV SCSILIB5 SEARCH=BULK CHECKLABEL=BARCODE VOLRANGE=YYY000L5,YYY999L5

The first checkin will pick up all the XXXnnnL4's, and the second checkin will 
pick up all the YYYnnnL5's.

If your volsers are all alpha, you'll probably need to have your operators put 
the L4's in the I/O door and run that checkin, then put the L5's in the I/O 
door and run the L5 checkin.

You won't run into any worse situation than what you have today, with both 
types of carts mixed in the same logical library.  The worst thing that's going 
to happen, is that you get the wrong tapes checked into the library, which 
means TSM can try to mount LTO5 carts in the LTO4 drives, and you'll get an I/O 
error when it tries to read or write.    If you have LTO4 and LTO5 carts in the 
same library today, and you run an audit library with checklabel=yes, I think 
you are subject to the same problem, unless you take the LTO4 drives offline.  
With separated logical libraries, you won't have those issues.  

You can't get any data damage, TSM still won't let you overwrite any data it 
shouldn't, even if the tape is checked into the wrong library, as both 
libraries and all data volumes belong to the same TSM DB.  So it's a totally 
harmless thing to try, as far as I know.

It's really no different than having 2 separate physical libraries attached to 
a TSM server; somebody can still throw the wrong cartridges into the I/O door!

I'm not sure if that was the answer you were looking for, if you have other 
specific questions or situations, feel free to mail back -
Wanda 



-----Original Message-----
From: ADSM: Dist Stor Manager [mailto:ADSM-L AT VM.MARIST DOT EDU] On Behalf Of 
Roger Deschner
Sent: Tuesday, June 12, 2012 6:27 PM
To: ADSM-L AT VM.MARIST DOT EDU
Subject: Re: [ADSM-L] UN-mixing LTO-4 and LTO-5

Defining separate libraries had occurred to me, but it seems like it could also 
be dangerous, if both logical libraries were to try to check in the same volume 
using a search. How do I avoid that? That is, if I create two libraries, one of 
them with the LTO-4 drives and the other with the LTO-5 drives, both libraries 
will have access to all the tape slots. Does this mean I cannot use CHECKIN 
LIBVOL SEARCH=YES but instead I should check in new volumes by name? Would this 
be similar to sharing a physical library with another application, except that 
the other application happens to be the same TSM server?

This configuration of two logical library definitions for one physical library 
would appear to have some risks. Or is it safe? Are there any other problems I 
should expect with this kind of configuration?

Roger Deschner      University of Illinois at Chicago     rogerd AT uic DOT edu



On Tue, 12 Jun 2012, Remco Post wrote:

>did you define separate libraries for those device classes?
>
>On 12 jun. 2012, at 08:15, Remco Post wrote:
>
>> check the format= option on your device class...
>>
>> On 12 jun. 2012, at 08:02, Roger Deschner wrote:
>>
>>> We have a tape library (Oracle/Sun/STK SL500) which contains both 
>>> LTO-4 and LTO-5 drives, and both LTO-4 and LTO-5 media. I am trying 
>>> to keep TSM from mounting an LTO-4 cartridge in an LTO-5 drive, but 
>>> it is insisting on doing it anyway.
>>>
>>> We have 4 LTO-4 drives and 3 LTO-5 drives. The mount limits for the 
>>> two devclasses are set accordingly - to 4 for the LTO-4 devclass and 
>>> 3 for the LTO-5 devclass. When a request to mount an LTO-4 cartridge 
>>> comes, it seems to use any of the 7 drives, regardless of whether it 
>>> is an LTO-4 or LTO-5 drive. Therefore some tape mounts for LTO-5 
>>> cartridges are failing or being delayed due to there being no 
>>> available LTO-5 drives when some of them are occupied by LTO-4 
>>> tapes. This is despite the claim in the section of the TSM 
>>> Administrator's Guide for AIX servers titled "Mount limits in LTO 
>>> mixed-media environments" (on book page 221 / physical page 249 in 
>>> TSM V6.2 for AIX, or book page 198 / physical page
>>> 232 at V6.3) that setting the mountlimit to the actual number of 
>>> earlier-generation drives will prevent the use of later-generation 
>>> drives for the earlier-generation devclass.
>>>
>>> BTW, this is a library manager configuration, which may complicate 
>>> things. The devclass definititions do match on the library manager 
>>> and both of its library clients. The library manager is at 6.2.2.30, 
>>> and its two clients are at 5.5.6.0 and 6.2.2.30.
>>>
>>> So, the question is, how do I prevent LTO-4 cartridges from being 
>>> mounted in LTO-5 drives? I would prefer not to use the hardware 
>>> library partitioning feature, which has its own set of hassles.
>>>
>>> Roger Deschner      University of Illinois at Chicago     rogerd AT uic DOT 
>>> edu
>>> ==== "NO OVERNIGHT CAMPING AUTOMATIC SPRINKLER SYSTEM IN OPERATION" 
>>> ==== ==== --sign, I-70 rest area, Parachute, Colorado 
>>> =======================
>>
>> --
>> Met vriendelijke groeten/Kind Regards,
>>
>> Remco Post
>> r.post AT plcs DOT nl
>> +31 6 248 21 622
>
>--
>Met vriendelijke groeten/Kind Regards,
>
>Remco Post
>r.post AT plcs DOT nl
>+31 6 248 21 622
>