Tracy Di Marco White wrote:

quoted text
>I have a machine with 4 tape drives attached, each on their own scsi
>chain, to do backups with.  I regularly get these timeouts, hanging
>the process accessing a drive, and requiring me to restart the machine,
>and causing problems with backups.  The tape drives are attached via
>ahc(4) cards.  It also has two spool disks, attached via mpt(4).
>  
>
See kern/21335 for an alternate description of your problem. Seems
to be linked to ahc. Any takers? (I am currently busy with NTP release and
timecounters)

Frank