ADSM-L

Re: Waiting for mount point even if there is a free one?

1997-04-30 02:46:56
Subject: Re: Waiting for mount point even if there is a free one?
From: Christo Heuer <christoh AT ABSA.CO DOT ZA>
Date: Wed, 30 Apr 1997 08:46:56 +0200
> Hi!
>
> I recently upgraded to ADSM/2 V2 (CSD Level 21020),
> and I believe this version waits occassionally for free tape slot even
> if there is one free.
> Example:
>
> Configuration: 2 tape drives of one device class DAT in one manual
> library. Mountlimit=2.
> Storage Pool PCBSDISK has 2 migration processes defined.
>
> At some time, there is one tape PCBS10 mounted, used for RESTORE
> Session.
>
> During this, 2 migration processes for PCBSDISK start.
>
> One of them (#8) can mount a tape, the second (#9) has to wait.
>
> Restore ends, leaving tape PCBS10 in IDLE state.
>
> But - migration process #9 still waits for mount point,
> tape PCBS10 remains in MOUNT/IDLE state.
>
> DISMOUNTING the tape manually does not help - process #9 still waits.
>
> CANcelling process #8 releases its tape.
> Because the disk storage pool PCBSDISK is still candidate for migration,
> a new migration process #10 is started instead. Now, each of both
> processes
> requires a tape and is able to mount it.
>
>
> Can someone explain me this behaviour ?
>
> Juraj SALAK
> KEBA Banking
> Linz, Austria

Hi Juraj,

You must look at your mount retention period in your devclass definition:
The default is 60 minutes.
Once a process has completed - in this case your restore process the tape is
retained in the drive for the time set in mount retention period.
If a process is cancelled it will ignore the mount retention period and
dismount
the tape immediately and the next process can use the drive as you have seen.

Hope this helps!

Regards
Christo Heuer
Johannesburg
South Africa
Christoh AT absa.co DOT za
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