scsi-target and the buffer cache

[Nate Lawson]

Scott Long wrote:
> Eric Anderson wrote:
> 
>> Nate Lawson wrote:
>>> Agree 100%.  While having it in usermode means there are boundary 
>>> crossings that increase per-transaction latency, the actual bulk data 
>>> transfer is via zero-copy IO and you should be able to exceed the 
>>> data transfer rates of several 10K RPM drives on decent hardware.
>>
>> Ok, great.. Now, will scsi_target work ok with raw devices, or only 
>> files?  (although I'm not sure theres all that much difference really).
>>
> 
> You can write your userland code to use whatever files or devices you
> want.  Are you talking about the scs_target.c code in
> /usr/share/examples?  That's just a skeletal example that you can use
> as a starting point for your own work.

No, it's not just a skeletal example.  You can point it at a raw device 
as the backing store file and it will work as a block device (i.e. RBC 
command set).  It has been tested as working at least moderately fast 
over SCSI, FC, and firewire.

-- 
Nate