What I ment was...

With VSE you have to use FICON
With VM you can use FICON or FCP
With z/Linux you can use FICON or FCP.

But, an adapter can only be Ficon or FCP.  So to use FCP with z/Linux,
you need an FCP adapter (one or more at $25k each) plus you need
something for VSE (one or more FICON adapters at $25k each).

In this mixed environment, you can use FICON for everything (at a cost
savings) or FICON and FCP adapters at an additional cost.

I wasn't aware that VSE now supports native FCP adapters.  If that is
so, and if you are at that level of VSE, then the dual adapters at extra
cost argument is moot.

You spoke of TSM, another sore point in this topic (for us smaller
shops).  TSM required scsi attached tape drives.  The IBM 3590 can be
either scsi or FICON/Escon attached.  In my case I needed mainframe
attached 3590s.  So to use TSM, I would have to have a separate set of
3590s that are scsi attached.

We are in the server consolidation mode.  And having to buy dedicated
hardware to support the "other" side, instead of being able to pool our
existing tape hardware, isn't goodness.

We were in the cost containment mode and buying another set of
dedicated tape drives for TSM wasn't in the upfront plans.

It might be the best way to go and in a few years, we might be there,
but I would rather spend the funds for an IBM Virtual Tape system
instead of having another set of dedicated tape drives.

I've put out the word that I want the the backing up of z/Linux in a
normal mainframe world, solved.  We use Dynam for the VSE world.  I've
asked CA for a z/Linux interface to Dynam.  I've asked for a z/Linux
interface for VMBACKUP (or any other decent backup product on a file
level side).

Then, there is Oracle.  Most of the Linux data will reside in Oracle
10g on SLES9.  Log archives.  Data archives.  Need this backed up.  Not
sure at this time, everything I will need in this area.  IBM VTS
support.  Disaster recovery.  Lights out envionment.  Is Flashcopy
required?  I don't know.  I will know many of these answers by the end
of Oct when I have Oracle running and I start to address these issues
before we go out for our "complete tape overhall/replacement" solution.

Going back on topic.  z/Linux throws enough curves in the thought
process.  Especially when we have to look down the road.  FCP and it's
requirements puts a little spit on that curve ball.

Large shops may have sufficient money to spend $100k to "try things".
Right off the bat, FCP didn't seem to buy us anything and caused a lot
of concerns about how it all ties together.

(when I say doesn't buy us anything, I'm talking that the possible
performance improvements don't mean anything to us at this time.  The
DS6800 is blowing us away as it is.  A few percentage points better
response isn't worth it at this time.)

Tom Duerbusch
THD Consulting

>>> [EMAIL PROTECTED] 09/23/05 11:46 AM >>>
some comments

> You would need one (or two) FCP adapters for Linux.
> You would need one (or two) Ficon adapters for VSE.
> VM could use either one.
> (we were very much in a cost containment mode)

I am not sure wether you are referring to technical feasibilty
or financial ... but technically all of them (Linux, VSE, VM)
can deploy both FICON and FCP.

> When VM emulated CKD on FCP, we could use the normal VM type
products.

Well, those disks would look like FBA disks and require to use
the Linux FBA-type disk device driver.
Native SCSI does perform better since it a)avoids overhead, and b)
allows to utilise concurrent SCSI command queueing.

> But when z/Linux was using native FCP, VM and it's products were out
of
> the picture.  I'm not sure if this would have been a good thing or
not.
> The backup/recovery method may turn out just to be too different to
> force the z/Linux side into the traditional mainframe mode.

Tools might be different. Choices for for tape backup devices might
be more abundant. TSM - to name an IBM product - is available for
Linux
on zSeries and is capable of using many different SCSI tapes library
and drives.

I have seen a presentation here at the zExpo where the presenter
spoke about a tape backup solution that that utilizes existing
backup infrastucture outside Linux. Don't have the link at hand ...
but should be available through IBM's website.

> VM supports PAV for z/Linux guests.  Extra charge for PAV support on
> the DS6800.  But the DS6800 has 32 virtual controllers available,
each
> with 256 addresses.  I'm not sure that I'm going to run out of
addresses
> anytime soon.  Perhaps the next box replacement will need PAV.

I think PAV is a painful circumvention for what SCSI provides for
free:
tagged command queueing, or, in other words, lots of SCSI command
that can run concurrently.

Martin Peschke
Linux on zSeries Development (mostly FCP)





Tom Duerbusch <[EMAIL PROTECTED]>
Sent by: Linux on 390 Port <[email protected]>
23/09/2005 17:48
Please respond to Linux on 390 Port


        To:     [email protected]
        cc:
        Subject:        Re: 3390 vs. FCP Connection to San running
scsi



When we ordered our z/890 and Shark (which turned into a DS6800
somewhere during the shipment<G>)...

I looked at FCP and just couldn't deal with it.

It seem...

A ficon adapter was $25k.
A FCP adapter was $25k.

You would need one (or two) FCP adapters for Linux.
You would need one (or two) Ficon adapters for VSE.
VM could use either one.
(we were very much in a cost containment mode)

When VM emulated CKD on FCP, we could use the normal VM type products.


But when z/Linux was using native FCP, VM and it's products were out
of
the picture.  I'm not sure if this would have been a good thing or
not.
The backup/recovery method may turn out just to be too different to
force the z/Linux side into the traditional mainframe mode.

The DS6800 can be partitioned into CKD and SAN sides.  The SAN side
can
be accessed as a normal SAN to the network or to the mainframe over
FCP.

But with partitioning the box, I have concerns on the increments that
can be moved on each side and how disruptive it is.  With all CKD, I
can
assign volumes in 1 GB increments, and with VM, on a cylinder basis as
everything is on the same side.

The DS6800 can support, in CKD mode a 3390 model 54.  So we also have
very large dasd support in either Ficon or FCP connections.

VM supports PAV for z/Linux guests.  Extra charge for PAV support on
the DS6800.  But the DS6800 has 32 virtual controllers available, each
with 256 addresses.  I'm not sure that I'm going to run out of
addresses
anytime soon.  Perhaps the next box replacement will need PAV.

I would think that native FCP would end up with slightly better
thruput
then FICON.  With CKD support in z/Linux, there is a device driver
that
converts native Linux dasd commands to CKD.  That is overhead.  That
is
cpu time.  Without it, I should get slightly better thruput.  In my
shop, the possible improvements isn't a driving factor, for now.



And, if I prove my self wrong and native FCP support is great, I can
always add it later.


Tom Duerbusch FCP, VM and it's products were out of
THD Consulting

>>> [EMAIL PROTECTED] 09/22/05 12:03 PM >>>
Good Afternoon.. I am new to this list.
We are a medium sized VM / VSE shop planning to
implement Linux running mainly Webshpere applications
on our Z890.

I am attempting to lay out the architecture for this
implementation. My question is what are the pro's and
con's of accessing scsi via an FCP connection to a San
vs. using 3390 storage. Any help would be appreciated.

Thanks in advance,

__________________________________________________
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