Since there has been some esp-lossage talk recently, I'm pretty unsure what
this effect is:

I have a U2, whith

esp0 at sbus0 slot 14 offset 0x8800000 vector 20 ipl 3: dma rev fas
: FAS366/HME, 40MHz, SCSI ID 7
scsibus0 at esp0: 8 targets, 8 luns per target
scsibus0: waiting 2 seconds for devices to settle...
sd0 at scsibus0 target 0 lun 0: <IBM, DNES30917SUN9.0G, SAD0> SCSI3 0/direct fixed
sd0: 8637 MB, 4926 cyl, 27 head, 133 sec, 512 bytes/sect x 17689267 sectors
esp0: wide mode 1
sd0: sync (100.0ns offset 5), 16-bit (20.000MB/s) transfers, tagged queueing
cd0 at scsibus0 target 6 lun 0: <TOSHIBA, XM-5401TASUN4XCD, 3485> SCSI2 5/cdrom removable
cd0: sync (248.0ns offset 15), 8-bit (4.032MB/s) transfers

On heavy load the esp driver fails with an endless loop of:

esp0: invalid state: 6
esp0: resetting SCSI bus
esp0: SCSI bus reset
esp0: invalid state: 6

Seems I have to power off the machine to get it back to live (break on serial
console *sometimes* works, but I can't do anything usefull there without
hanging the system)

Is this a hardware problem? I checked cabling (as far as you can do that with
the internal first disk in an U2), and solaris seemed to work just fine (but
I didn't stress it hard).

Is the disk at fault? It seems to be a bit slow, so I'm considering replacing
it anyway (but due to my lack of clue for recent SCSI developement - last I
had a SCSI-2 disk on an adaptec 1742 - I'm pretty confused by the new terms
like LVD and don't know yet what disk would work in this machine).

Or is this another symptom of lossage in the driver?

Martin