[Stgt-devel] Adding Virtual Tape & Changer targets

[Mark Harvey]

On 3/22/07, Ming Zhang <blackmagic02881 at gmail.com> wrote:
> On Wed, 2007-03-21 at 13:32 -0700, Mark Harvey wrote:
> > The aim is to support the SSC-3 and SMC-3 standards - eventually. No
> > actual code that says "emulate robot xyz".
>
> different robots will have different capability and even the code
> support every feature defined in SSC and SMC, it still need to present
> it to host as a specific model.
>
> but of course having more features implemented and allowing each model
> to assemble them is nice.
>
> > The vtl code I'm using reports as a STK L700 with no ill side effects.
> >
>
> which VT model u report?
>
> > The actual VENDOR Ident, Product Ident etc for the SCSI Inquiry string
> > are to be retrieved from a configuration file - and hence code
> > independent.
> >
> > I hope nobody shoots me for hijacking the '-b <backing file>' option for
> > use as the configuration file for SSC and SMC devices..
>
> it will be wonderful if a VTL can be configurable purely from a file.
> and virtual device in tgt is in user space so open a file is really
> ok. ;)
>
> aha, u work for the company who make VBE, so can u run a VBE
> interoperability test on your code?!
This is the reason for creating the VTL code.
i.e.
Lack of available hardware to support NetBackup.
Real tape libraries cost lots of $$$ and trying to get one per support
tech is just unrealistic.
There is also lots of different flavors of operating systems in the
support lab, so interoperability testing with different iSCSI
initiators will be possible.

The BackupExec support guys are also co-located on the same floor so
I'll be able to get interoperability tests with BackupExec as well
using the Microsoft iSCSI initiator.

In a previous life, I also installed and configured NetWorker (Its
been 5+ years since I touched this, but I should be able to figure out
how to run it again).

I'm also interested in Persistent SCSI reserve/release - latest
version of NetBackup (in beta at the moment) will be using this so
this will be another area of code I'll most likely be looking at. Once
the tape drive & library side of things are working..

>
> >
> > Once I clean up some comments in the code, I shall post a diff.
> >
> > Cheers
> > Mark Harvey
> >
> > -----Original Message-----
> > From: stgt-devel-bounces at lists.berlios.de
> > [mailto:stgt-devel-bounces at lists.berlios.de] On Behalf Of Ming Zhang
> > Sent: Thursday, 22 March 2007 12:44 AM
> > To: Mark Harvey
> > Cc: stgt-devel at lists.berlios.de
> > Subject: Re: [Stgt-devel] Adding Virtial Tape & Changer targets
> >
> > On Wed, 2007-03-21 at 12:39 +1100, Mark Harvey wrote:
> > > A quick introduction.
> > >
> > > I am planning on adding support to the stgt for both SSC and SMC
> > > devices with the aim of full Virtual Tape Library support.
> > >
> > > I have a working VTL based around the scsi_debug kernel module +
> > > char-device 'back-end' to pass SCSI commands thru to user-space
> > > daemons (which poll the char device looking for work to do). These
> > > daemons act as the SSC or SMC devices.
> > >
> > > This VTL I have had working for over 12mths.
> >
> > side question, your SSC/SMC code support to emulate one particular
> > VT/VTL or you will provide a framework to allow the emulation of
> > multiple different types of VTLs and VTs?
> >
> > suggest you to release the code early so people can give you more
> > feedback.
> >
> > thanks for the great work.
> >
> > Ming
> >
> >
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>
>