Yes, BDAM can use the key portion, however faster access was achived if the
lookup value for finding a record was mapped by some calculation into
CCHHR; otherwise BDAM's performance was not much better than ISAM's
There was an article in Datamation (back when it was a good magazine) called
For VSE with FBA devices, the VTOC wasn't keyed as it was on a CKD device;
it's been years since I used a 3310 or a 3370; so I'm stretching here; but
the if I remember correctly, the vtoc was built on a VSAM KSDS model.
Yes, BDAM can use the key portion, however faster access was achived if the
The CKD's ability to handle separate keys from the data was born in the days
of ISAM, when an indexed file was literally written with the index on the
track. If the ISAM file was unblocked, then each record had the key for that
record written first, then the data; an index search was data at the
Has anyone tried iSCSI with S/390 ?
Yes. The limiting factor is currently network adapter performance, but it
does work for everything except IPL (duh). We're doing a bit more stress
testing internally before letting it loose on the world.
-- db
Really? As in talking to existing Fiber Channel[1] disk
arrays that speak
FC-SCSI? and/or via FC-SCSI bridges to random SCSI devices?
Where can I find
out more? I used to work on FC-attached storage array systems
at Compaq...
Yup. They were demonstrating it at LinuxWorld in NYC in January.
The only folks that would really be in trouble are those who wrote code to
mathmaticaly map some data value into a CCHHRR value, which is what Direct
Access Method originally did. These people would have to come up with a way
to convert their key value to a relative record number instead of
I said (to John):
S/390 does also have FBA (fixed block architecture) DASD devices.
Sadly, even in the Linux world these are not widely known or used.
I maintain that they should be employed heavily and heartily!
The benefits are numerous.
On Thu, 18 Apr 2002, Jay Maynard wrote:
[EMAIL PROTECTED] said:
Right. And since the actual backing store is fixed-block, I say let
that which is presented also be fixed-block and ditch the track,
record, count, and key info and the associated work.
With CKD, Linux must play the C/H/S game. With emulated CKD, so must
the DASD
Note that CD can be presented as FBA *today* on some S/390.
Specifically, for P/390 (and presumably for Multiprise) a CD image,
a .iso file, can be configured to the S/390 as an FBA.
Yup. Works on a Multiprise too, as Dave Jones can attest.
Adam
On Thu, Apr 18, 2002 at 12:44:13PM -0500, Adam Thornton wrote:
Note that CD can be presented as FBA *today* on some S/390.
Specifically, for P/390 (and presumably for Multiprise) a CD image,
a .iso file, can be configured to the S/390 as an FBA.
Yup. Works on a Multiprise too, as Dave
On Thu, Apr 18, 2002 at 10:44:39AM -0500, Rick Troth wrote:
And what will happen now with SCSI attachment to zSeries?
I can only hope that there will NOT be some CKD protocol.
It just doesn't seem worth it when FBA is what is really happening.
Probably so, at least for VM, VSE, and Linux.
VSE used the FBA devices, 3310 3370s, in the 80s.
As of VSE 2.4, 3310s are not listed as supported, and 3370s are listed as
data volumes only, not for systems or installation use.
There is a 9336 listed under FBA that appearently can still be used as a
system or installation device, but I'm
On Thu, Apr 18, 2002 at 01:04:28PM -0500, Jay Maynard wrote:
On Thu, Apr 18, 2002 at 12:44:13PM -0500, Adam Thornton wrote:
Note that CD can be presented as FBA *today* on some S/390.
Specifically, for P/390 (and presumably for Multiprise) a CD image,
a .iso file, can be configured to
On Thu, Apr 18, 2002 at 08:27:35PM +0200, Florian La Roche wrote:
if the author of hercules wants to have this, I'll reconsider this for
the next rawhide upload. :-)
That would be nice. Thanks!
I must point out, though, that I'm not really the author of Hercules; I'm
just the guy who gets to
For VSAM it isn't that bad; and Relative Byte Address is a Relative Byte
Address, on FBA it's a little easier becasue you just map from the first
byte on the pack. VTOC's used the relative record approach instead of an
CCHHRR.
Garry E. Ward
Senior Software Specialist
Maritz Research
Automotive
-Original Message-
From: Linux on 390 Port [mailto:[EMAIL PROTECTED]]On Behalf Of
Adam Thornton
Sent: Thursday, April 18, 2002 10:44 AM
To: [EMAIL PROTECTED]
Subject: Re: FBA for Jay [was: Re: How to pre-allocate a 4GB File?]
Note that CD can be presented as FBA *today* on some
On Thu, Apr 18, 2002 at 11:17:45PM +0200, Phil Payne wrote:
Mainframers - at least MVS types - aren't used to thinking that way. A sile
as a stream of bytes is completely alien to them.
System types, or application types? We've had RBA since VSAM I - lots of things
like DB2 logs
are
Mainframers - at least MVS types - aren't used to thinking that way. A sile
as a stream of bytes is completely alien to them.
System types, or application types? We've had RBA since VSAM I - lots of things like
DB2 logs
are RBA-governed.
--
Phil Payne
http://www.isham-research.com
+44
On Thursday, 04/18/2002 at 10:44 EST, Rick Troth [EMAIL PROTECTED] wrote:
And what will happen now with SCSI attachment to zSeries?
I can only hope that there will NOT be some CKD protocol.
It just doesn't seem worth it when FBA is what is really happening.
As hard as it might be to believe,
Really? As in talking to existing Fiber Channel[1] disk arrays that speak
FC-SCSI? and/or via FC-SCSI bridges to random SCSI devices? Where can I find
out more? I used to work on FC-attached storage array systems at Compaq...
Has anyone tried iSCSI with S/390 ?
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