[Info-vax] Caution: LTT ignores ALLOCATE

[Rob Brown]

On Thu, 6 Oct 2011 at 21:58 +0200, Johnny Billquist wrote:

> On 2011-10-06 16.55, Dale Dellutri wrote:
>>> On Oct 5, 10:36?am, Dale Dellutri<ddelQQQl... at panQQQix.com>  wrote:
>>>> I use LTT (Library and Tape Tool) to test tape drives and 
>>>> cartridges. I just discovered that it ignores the fact that 
>>>> another processes may have exclusive access to the drive via the 
>>>> ALLOCATE command.
>>>> 
>>>> LTT is clearly not originally written for OpenVMS, and it shows.
>> 
>> I didn't mean to start a long thread about this.  I was just 
>> surprised that LTT ignored the allocate, and wanted to warn others 
>> so that they would be cautious using LTT.
>> 
>> I logged in as SYSTEM, allocated the drive, loaded a cartridge, and 
>> did some tape manipulations.  (The cartridge was new, and will be 
>> used as a backup tape.)
>> 
>> =====
>> $ allocate mkd600:
>> %DCL-I-ALLOC, _XX$MKD600: allocated
>> $ init mkd600: DAILY4
>> $ mou/for/noass mkd600:
>> %MOUNT-I-MOUNTED, DAILY4 mounted on _XX$MKD600:
>> $ dism /nounl mkd600:
>> $ sho dev mkd600: /full
>> 
>> Magtape XX$MKD600:, device type COMPAQ SDLT320, is online, 
>> allocated, record-
>>      oriented device, file-oriented device, available to cluster, 
>> error logging
>>      is enabled, controller supports compaction (compaction 
>> disabled), device
>>      supports fastskip (per_io).
>>
>>      Error count 159 Operations completed 1702975163
>>      Owner process "SYSTEM"  Owner UIC [SYSTEM]
>>      Owner process ID 000BF851 Dev Prot S:RWPL,O:RWPL,G:RWPL,W:RWPL
>>      Reference count 1 Default buffer size 512
>>      Density default Format Normal-11
>>
>>    Volume status:  no-unload on dismount, beginning-of-tape, odd 
>> parity. =====
>> 
>> Note that I didn't deallocate the drive and I didn't log out.
>> 
>> Then I opened a second window and logged in separately again
>> to SYSTEM, and tried some vms commands ...
>> 
>> =====
>> $ allocate mkd600:
>> %SYSTEM-W-DEVALLOC, device already allocated to another user
>> $ init /med=com mkd600: DAILY4
>> %SYSTEM-W-DEVALLOC, device already allocated to another user
>> =====
>> 
>> ... and, as expected, these commands respect the fact that
>> another process has allocated the drive.  However, I then
>> started LTT in this second login, and it ran a read/write
>> test on the cartridge in the drive without complaint or
>> even warning.  I'm using version 4.13 of LTT (URL below
>> is wrapped):
>> 
>> =====
>> http://h20000.www2.hp.com/bizsupport/TechSupport/
>>    DriverDownload.jsp?
>>    pnameOID=406731&locale=en_US&taskId=135&
>>    prodTypeId=12169&prodSeriesId=406729
>> 
>> HP StorageWorks Library and Tape Tools (Alpha)
>> Type:	Diagnostic
>> Version:	4.13 SR1 (14 Sep 2011)
>> Operating System(s):	OpenVMS, OpenVMS v7.3-2,
>>   OpenVMS v8.2, OpenVMS v8.3, OpenVMS v8.4
>> File name:	hp-axpvms-ltt-v0413-0-1.zipexe (12 MB)
>> =====
>> 
>> If you don't want to reconstruct the URL above, just
>> google for
>>    hp openvms library tape tool
>> 
>> The SYSTEM account has its usual privileges.  And the system is:
>> 
>> =====
>> $ sho sys /noproc
>> OpenVMS V8.2 on node XX 6-OCT-2011 09:15:02.24  Uptime 542 15:16:07
>> =====
>
> And if you check what privileges the SYSTEM user have, you'll notice 
> that it have SHARE, which means it can assign channels to non-shared 
> devices. Ie. it can bypass the allocate status of a device.

And yet it was unable to when Dale attempted to ALLOCATE or 
INITIALIZE.

> This has nothing to do with the LTT, and everything to do with who 
> you are and what privileges you have.

I disagree.  Dale's demonstration clearly shows that when another user 
has the device allocated, user SYSTEM (which, as you pointed out, is 
fully privileged and can bypass the allocate status of a device if it 
wants to) can *not* allocate or initialize the tape for himself.

If ALLOCATE and INITIALIZE respect a device allocated to another user 
but LTT does not, I do not think that you can say that it has "nothing 
to do with the LTT".

- Rob


-- 

Rob Brown                        b r o w n a t g m c l d o t c o m
G. Michaels Consulting Ltd.      (780)438-9343 (voice)
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