Re: Emulated tape/ECKD disk

[Jeff Gribbin, EDS]

I recall how excited I was when I first learned about the *CCS support 

mechanism that is used to support VTAM logon terminals in CP. The concept
 
of having an RDEVBLOK as the gateway to a server (didn't call 'em servers
 
back then - big mistake) opened up so many possibilities for device 
emulation and mapping that I (then) felt that it was OBVIOUS that this 

interface would be extended to other device types - providing a general-
purpose API for using a server to emulate any kind of RDEV that CP 
supports.

Alas, in those young, exciting days I was horribly naive and didn't 
understand words like, "business case". I'm thankful that David, however,
 
does. If implemented, this proposal would, in my view, be the best thing 

to happen to VM since Linux. (Sliced bread? Doesn't even come close.)

Re: (off topic) sump pump

[Harding, Mike]

But your ground floor might be 3' under water. 


Mike Harding
EDS VM National Capability
134 El Portal Place
Clayton, Ca.  USA  94517-1742

* phone: +01-925-672-4403
*  Fax: +01-925-672-4403
* mailto:[EMAIL PROTECTED]   * 
(personal)
Note:  For 2005, I am off on Fridays with even Julian dates and Mondays
with odd ones.


-Original Message-
From: The IBM z/VM Operating System [mailto:[EMAIL PROTECTED] On
Behalf Of Dave Jones
Sent: Monday, May 15, 2006 6:42 AM
To: IBMVM@LISTSERV.UARK.EDU
Subject: Re: (off topic) sump pump

Or consider relocating to Houston, where housing costs are low and there
are no basements;-)

DJ

Richard Corak wrote:
>> The sump pump in my basement shorted out.
> 
> 
> I suggest a search using keywords like
> 
> +"sump pump" +"backup" +"water powered"
> 
> Richard Corak

Emulated tape/ECKD disk

[David Boyes]

Several people asked off-list just what I had in mind wrt to emulated 
tape and disk over SCSI/FCP. Attached below is a draft of what I've got 
so far. If this is something you could support (and your company would 
support), please let me know.  


-- db


SCSI Support Extension Proposal

Desired Action: 

Complete the emulated device over SCSI/FCP support introduced in z/VM
to include both ECKD disk emulation on SCSI/FCP and
emulation of channel-attached tape to generic SCSI/FCP tape
devices. If possible, the tape emulation should also support a remote tape
server option, mapping the emulated device to a user specified process
over a network connection.

Business Justification: 

1) In many small to medium-sized shops, the amount of money available
   to invest in mainframe technology is limited compared to the
   funding accessible to the open systems environment. Often,
   significant disk and tape resources are duplicated or
   over-provisioned in the open systems environment, but are not
   accessible for reuse in the mainframe environment due to the
   requirement for specialized interfaces and separate management to
   support mainframe-specific environments. Enabling software
   emulation of mainframe devices on top of a generic SCSI/FCP
   infrastructure would allow System z infrastructure to leverage
   these existing enterprise infrastructure investments directly,
   improving the TCO argument for maintaining System z-based
   infrastructure. 

   (It is clearly acknowledged that software emulation has a
   performance impact compared to native ECKD over FICON. In many
   cases, this performance vs cost tradeoff is acceptable in that the
   development curve for device and storage area network performance
   often offsets the disadvantage within a relatively short period of
   time, and the cost savings is often an acceptable tradeoff vs
   execution time delays due to longer I/O delays. )

2) Even given the recent price reductions for the System z BC and EC
   machines, in some cases, the cost differential to implement
   separate disk for a System z environment (or add specialized
   interfaces to support FICON attachment of an existing disk array)
   is such that disk pricing is a deciding factor to preserve a System
   z environment.

   Similarly, environmental issues (floor space, power consumption,
   heat dissipation) may dictate that additional disk units to support
   only a single platform argue against retaining the System z
   solution as a "difficult to interoperate with" solution.

3) Additional disk volume formats and attachment methods complicate
   storage management discipline, adding additional training costs
   for storage administrators and possibly additional costs for
   software implementation to manage the FICON-attached arrays (not
   all vendors support FICON-attached volumes in their basic
   management software, but market that support as a enhanced
   feature). This increase in complexity further impacts the ROI and
   TCO of the System z solution. 

4) Currently, only VSE, Linux and VM fully support FBA DASD. We are
   aware of work being done to z/OS to tolerate FBA disk, but until
   this work is completed, ECKD disk is required.  If IBM is to open
   up additional market opportunity for z/OS or other ECKD-only
   systems in the short term, ECKD emulation is necessary to open
   those opportunities.  

   It is important to note that ECKD emulation on SCSI disk has been
   done in the past for the P/390, R/390, and Multiprise systems, and
   it is clear from a cursory examination of the z/VM EDEV SCSI stack
   that these previous attempts could be used as a starting point to
   provide this type of emulated function. 

5) With regard to tape, currently the largest supported FICON-attached
   tape unit supports a 40G uncompressed volume. Open systems tape
   units regularly support 200G or greater volume sizes. With the
   dramatic increase in data volumes, the inability of System z to
   access these commonplace devices argues significanly against
   adoption of a System z based solution in place of a Intel or other
   platform solution. 

6) Similar to the ECKD disk emulation code mentioned above, tape
   emulation code for 3420 and 3480/90 tape over SCSI also exists, and
   offers direct support for all System z operating systems currently
   supporting tape without additional development. Emulated tape
   devices could easily be mapped to higher-capacity SCSI devices,
   providing direct benefit for backup/DR and data exchange purposes. 

7) Adding ECKD and tape emulation would allow dramatic simplification
   of software distribution for System z operating systems, allowing
   applications to be directly supplied as disk images on inexpensive
   media (CDROM vs tape cartridges). This simplification would allow
   inexpensive distribution methods to be used in the future, as well
   as sophisticated verification tools that are not possible with
   tape-based

Re: Problems with Linux and VM

[Larry Macioce]

I'm thinking someone stepped on the root file sys. We haven't made any 

chancges to this system in seveal months  and have booted it just 5 days 

ago and the developers have been working on it transfer files yesterday.
Mace

Re: Problems with Linux and VM

[Adam Thornton]

On May 16, 2006, at 8:28 AM, Larry Macioce wrote:

We lost the the putty connection this morning and when I went to  
reboot


linux through vm I rec'ed the following:

Warning: unable to open an initial
console.

Kernel panic: No init found.  Try passing init= option to
kernel.
01: HCPGSP2629I The virtual machine is placed in CP mode due to a  
SIGP st

op
from
 CPU
00.


00: HCPGIR450W CP entered; disabled wait PSW 000A
80100570





Did a help but it told me something I already knew that the we were  
stopp

ed
I just don't know why.

Any help is greatly appreciated



Did you apply service to the kernel and perhaps not run mkinitrd  
before the reboot?


Did someone else suddenly and forcibly link to your root filesystem  
disk so you don't have it anymore?


It also looks like you don't have /dev/console as a character block  
device (5,0 I think) but if you're missing the filesystem.


Adam

Re: Problems with Linux and VM

[Gianfranco Ciotti]

Larry Macioce wrote:
We lost the the putty connection this morning and when I went to reboot 
linux through vm I rec'ed the following:


Warning: unable to open an initial 
console. 
Kernel panic: No init found.  Try passing init= option to 
kernel.   



Did you have update your linux system? Sound linux kernel update without 
running zipl command.


--

Gian

Re: Problems with Linux and VM

[Larry Macioce]

Let me add this was a working system this just happened

thanks
Mace

Problems with Linux and VM

[Larry Macioce]

We lost the the putty connection this morning and when I went to reboot 

linux through vm I rec'ed the following:

Warning: unable to open an initial 
console.  
   
Kernel panic: No init found.  Try passing init= option to 
kernel.   
01: HCPGSP2629I The virtual machine is placed in CP mode due to a SIGP st
op 
from
 CPU 
00.
 
   
00: HCPGIR450W CP entered; disabled wait PSW 000A 
80100570  
 
 
 
 

Did a help but it told me something I already knew that the we were stopp
ed 
I just don't know why.

Any help is greatly appreciated

thanks
Mace

{SPAM?} Re: virtual memory

[jmfbahciv]

In article <[EMAIL PROTECTED]>,
   Anne & Lynn Wheeler <[EMAIL PROTECTED]> wrote:
>[EMAIL PROTECTED] writes:



Just for clarification:  I don't think I ever knew
how TOPS-10 did the stuff at this level.  I do
remember discussions about it all but I understood 0%
of what the guys talked about.  I no longer can
recall what was said, let alone the order.

ISTM that DECUS had some sessions about all this stuff.
Is any of those session writeups available?


/BAH

OT: Upgrading zVM 5.1 to 5.2

[David Boyes]

> (And I would rather discuss the subjective nature of reality,
religion,
> sex education in public schools,

Given our SHARE installation code (SIN), all I'm gonna say is: 

"Sin. Indulge in it. We're pretty accommodating." 

8-)

-- db

(For the humor-impaired, this message does not advocate illegal or
immoral acts, or even the installation of z/OS. YMMV. No express
warranty included.)