Multipath Failover & the HSG80

Hello to the group, and I hope there is a kind sole out there with
insight into the working of the HSG80.

Need the Rosetta Stone, AKA: inside information on the SCSI command
required by a system driver to switch a device from Port to Port. I
located a small statement in a LINUX users group that suggests a SCSI
Start command is all it takes. When I run a SCSI command, like read
capacity, down the NON-Preferred path of an HSG80 at Firmware 8.71F I
get a device not ready sense response. This would seem to suggest that
a start command is needed. So it agrees with the LINUX groups info. I
was just wondering if there is anyone out there that has written
Multipath Failover drivers for the COMPAQ HSG80 controller. And if
there are any known problems that I should prepare for. Also does the
HSG80 start command allow for status after the switch over has
completed, or if the driver needs to poll for completion.

Thanks for reading, and hope to hear from the HSG80 Guru's out there.
Bill.

"Bill Nadzam" wrote in message
om...
Hello to the group, and I hope there is a kind sole out there with
insight into the working of the HSG80.

Need the Rosetta Stone, AKA: inside information on the SCSI command
required by a system driver to switch a device from Port to Port. I
located a small statement in a LINUX users group that suggests a SCSI
Start command is all it takes. When I run a SCSI command, like read
capacity, down the NON-Preferred path of an HSG80 at Firmware 8.71F I
get a device not ready sense response. This would seem to suggest that
a start command is needed. So it agrees with the LINUX groups info. I
was just wondering if there is anyone out there that has written
Multipath Failover drivers for the COMPAQ HSG80 controller. And if
there are any known problems that I should prepare for. Also does the
HSG80 start command allow for status after the switch over has
completed, or if the driver needs to poll for completion.

Thanks for reading, and hope to hear from the HSG80 Guru's out there.
Bill.

If you're looking to implement an alternative to
http://h18006.www1.hp.com/products/s...ath/linux.html I can't
really help you. I guess HP won't be too helpful since their implementation
is licensed.
/charles

Hello, and thanks for the time;

I need to write a failover driver for a SAN appliance. So; I can not
use a standard LINUX driver. I have a working driver for the
Transparent failover, but not for the Multipath Failover. I am going
to try the Start Unit Command as the switch over.

Follow up! After sending the SCSI Start Command I do get farther, Read
Cap works, and such, but have A SCSI status of 0x18, AKA: Reservation
Conflict.
Sign* Now what.

Some versions of HSG fw were very buggy with regard to persistent
reservation. My only suggestion is to make sure you're current...

On 22 Dec 2003, Bill Nadzam wrote:

Follow up! After sending the SCSI Start Command I do get farther, Read
Cap works, and such, but have A SCSI status of 0x18, AKA: Reservation
Conflict.
Sign* Now what.


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