On Tue, Sep 06, 2005 at 04:28:01PM -0500, Dave C Boutcher wrote:
> This device driver provides the SCSI target side of the "virtual
> SCSI" on IBM Power5 systems. The initiator side has been in mainline
> for a while now (drivers/scsi/ibmvscsi/ibmvscsi.c.) Targets already
> exist for AIX and OS/400.
Please try to integrate that with the generic scsi target framework at
http://developer.berlios.de/projects/stgt/.
On Wed, Sep 07, 2005 at 12:49:32PM +0200, Christoph Hellwig wrote:
> On Tue, Sep 06, 2005 at 04:28:01PM -0500, Dave C Boutcher wrote:
> > This device driver provides the SCSI target side of the "virtual
> > SCSI" on IBM Power5 systems. The initiator side has been in mainline
> > for a while now (drivers/scsi/ibmvscsi/ibmvscsi.c.) Targets already
> > exist for AIX and OS/400.
>
> Please try to integrate that with the generic scsi target framework at
> http://developer.berlios.de/projects/stgt/.
There hasn't been a lot of forward progress on stgt in over a year, and
there were some issues (lack of scatterlist support, synchronous and
serial command execution) that were an issue when last I looked.
Vlad, can you comment on the state of stgt and whether you see it
being ready for mainline any time soon?
--
Dave Boutcher
From: Dave C Boutcher <[email protected]>
Subject: Re: [RFC] SCSI target for IBM Power5 LPAR
Date: Wed, 7 Sep 2005 07:45:04 -0500
> On Wed, Sep 07, 2005 at 12:49:32PM +0200, Christoph Hellwig wrote:
> > On Tue, Sep 06, 2005 at 04:28:01PM -0500, Dave C Boutcher wrote:
> > > This device driver provides the SCSI target side of the "virtual
> > > SCSI" on IBM Power5 systems. The initiator side has been in mainline
> > > for a while now (drivers/scsi/ibmvscsi/ibmvscsi.c.) Targets already
> > > exist for AIX and OS/400.
> >
> > Please try to integrate that with the generic scsi target framework at
> > http://developer.berlios.de/projects/stgt/.
>
> There hasn't been a lot of forward progress on stgt in over a year, and
> there were some issues (lack of scatterlist support, synchronous and
> serial command execution) that were an issue when last I looked.
The generic scsi target framework (stgt) is not SCST (that Vlad has
maintained). It is the project that Mike Christie and I started last
month. We discussed it with Christoph and decided that it would be
better to start from scratch because of the design differences.
Dave C Boutcher wrote:
> On Wed, Sep 07, 2005 at 12:49:32PM +0200, Christoph Hellwig wrote:
>
>>On Tue, Sep 06, 2005 at 04:28:01PM -0500, Dave C Boutcher wrote:
>>
>>>This device driver provides the SCSI target side of the "virtual
>>>SCSI" on IBM Power5 systems. The initiator side has been in mainline
>>>for a while now (drivers/scsi/ibmvscsi/ibmvscsi.c.) Targets already
>>>exist for AIX and OS/400.
>>
>>Please try to integrate that with the generic scsi target framework at
>>http://developer.berlios.de/projects/stgt/.
>
>
> There hasn't been a lot of forward progress on stgt in over a year, and
> there were some issues (lack of scatterlist support, synchronous and
> serial command execution) that were an issue when last I looked.
>
stgt is not scst. It is new. And yes we will have proper support for
sccatterlists. We need something similar to what sg and st need so I
plan on using the block layer functions that are implemented for those
upper layer drivers for stgt. If you want to help out and implement that
then that would be good. We are also very early in our design so all
comments are welcome.
FUJITA Tomonori wrote:
> month. We discussed it with Christoph and decided that it would be
> better to start from scratch because of the design differences.
Some of the things we are trying to improve upon are things that are
better supported in 2.6. Some differences:
- We will support controller hotplug.
- We allow any type of device (dm, scsi, ide, LVM@ etc) as storage. And
we do not want hook into SCSI-ml's upper layer drivers and deal with
that refcounting if we can help it so we push a lot of code to userspace
and only do reads and writes in the kernel.
- We also hope to support any block layer target.
- As mentioned before, scatterlists by using the block layer's support.
There may be more that I am forgetting, but originally we started out by
trying to clean up the SCST code for 2.6 and make it resemble SCSI-ml's
hotplug model. As we did this it looked like some code could live in
userspace and it would end up being a rewrite becuase there was so much
to do so we started a new project. We hope to work with Vlad and the
SCST developers.
Dave C Boutcher wrote:
> On Wed, Sep 07, 2005 at 12:49:32PM +0200, Christoph Hellwig wrote:
>
>>On Tue, Sep 06, 2005 at 04:28:01PM -0500, Dave C Boutcher wrote:
>>
>>>This device driver provides the SCSI target side of the "virtual
>>>SCSI" on IBM Power5 systems. The initiator side has been in mainline
>>>for a while now (drivers/scsi/ibmvscsi/ibmvscsi.c.) Targets already
>>>exist for AIX and OS/400.
>>
>>Please try to integrate that with the generic scsi target framework at
>>http://developer.berlios.de/projects/stgt/.
>
>
> There hasn't been a lot of forward progress on stgt in over a year, and
> there were some issues (lack of scatterlist support, synchronous and
> serial command execution) that were an issue when last I looked.
>
> Vlad, can you comment on the state of stgt and whether you see it
> being ready for mainline any time soon?
Sorry, I can see on stgt page only mail lists archive and not from start
(from Aug 22). Mike, can I see stgt code and some design description,
please? You can send it directly on my e-mail address, if necessary.
Vlad
Vladislav Bolkhovitin wrote:
> Dave C Boutcher wrote:
>
>> On Wed, Sep 07, 2005 at 12:49:32PM +0200, Christoph Hellwig wrote:
>>
>>> On Tue, Sep 06, 2005 at 04:28:01PM -0500, Dave C Boutcher wrote:
>>>
>>>> This device driver provides the SCSI target side of the "virtual
>>>> SCSI" on IBM Power5 systems. The initiator side has been in mainline
>>>> for a while now (drivers/scsi/ibmvscsi/ibmvscsi.c.) Targets already
>>>> exist for AIX and OS/400.
>>>
>>>
>>> Please try to integrate that with the generic scsi target framework at
>>> http://developer.berlios.de/projects/stgt/.
>>
>>
>>
>> There hasn't been a lot of forward progress on stgt in over a year, and
>> there were some issues (lack of scatterlist support, synchronous and
>> serial command execution) that were an issue when last I looked.
>>
>> Vlad, can you comment on the state of stgt and whether you see it
>> being ready for mainline any time soon?
>
>
> Sorry, I can see on stgt page only mail lists archive and not from start
> (from Aug 22). Mike, can I see stgt code and some design description,
> please? You can send it directly on my e-mail address, if necessary.
goto the svn page for the code
http://developer.berlios.de/svn/?group_id=4492
As for design desc, I do not have anything. It is the evolving source :)
We are slowly merging leasons we learned from open-iscsi, your SCST
code, the available software and HW targets, and the SCSI ULD's
scatterlist code which needs redoing so it is a bit of a mess.
Mike Christie wrote:
> Vladislav Bolkhovitin wrote:
>> Sorry, I can see on stgt page only mail lists archive and not from
>> start (from Aug 22). Mike, can I see stgt code and some design
>> description, please? You can send it directly on my e-mail address, if
>> necessary.
>
> goto the svn page for the code
> http://developer.berlios.de/svn/?group_id=4492
>
> As for design desc, I do not have anything. It is the evolving source :)
> We are slowly merging leasons we learned from open-iscsi, your SCST
> code, the available software and HW targets, and the SCSI ULD's
> scatterlist code which needs redoing so it is a bit of a mess.
OK, thanks, will try tomorrow.
I put SCST 0.9.3-pre1 on its page
(http://sourceforge.net/projects/scst/). This is not the latest, but
this is the one, which working. At the end of this week I'll try to put
there the latest one as well. Hope, you will learn some more lessons
from it :).
Any comments are welcome.
Vlad