I remember having to do that back when I used Solaris in PROD backup 
environments, seemed to be what was needed.

On Mon, 22 Oct 2007, Dave Markham wrote:

> Im not sure if its still relevant for Solaris 10 but i remember in the
> device admin guide it mentions that solaris unloads the least used
> devices should the system be busy. These are usually tapes and so it
> recommends adding the following lines into /etc/system
>
> forceload: drv/st
> forceload: drv/sg
>
> Just a thought.
>
> Cheers
>
> Hudson, Steve wrote:
>>
>> Folks has anyone seen the issue we are seeing on Solaris 10. We have a
>> Media Server that is at Solaris 10 with the Leadville Driver on the
>> HBA and we are running Netbackup Enterprise Server version 5.1 MP5.
>> Our tape drives keep disappearing from the O/S and the drives go down.
>> Either a reboot or a running of the CFGADM utility
>>
>> Is necessary to get everything back. This is becoming quite painful.
>> It seems from what I have seen on this list most people are very happy
>> with Solaris 10 and I am wondering if those folks are at NBU 6.0 MP4
>> or even NBU 6.5. Thanks in advance?.
>>
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