Discussion:
Merging CKD DASD image files
(too old to reply)
Gonzalo Martin Barrio gonzalobarrio@gmail.com [hercules-390]
2016-02-01 02:14:58 UTC
Permalink
Hi,

Hope this is the right group to post this to; otherwise I'd appreciate it
if you can point me in the right direction.

I have some large CKD DASD image files (as detected by the 'file' command).
Each image seems to be split in two files (old OS limitations?), first file
is around 2 GB, second file is around 700 MB.

I want to compress these, but when I try to I can only compress the first
(biggest) file, and the result is useless.

So, my question is: is there a utility that will allow me to merge the 2
image files into 1 file?
If there isn't, can someone provide with the manual steps to do so?

Thanks in advance.
kerravon86@yahoo.com.au [hercules-390]
2016-02-01 02:27:43 UTC
Permalink
This is the correct group, but I don't
know the answer to your question
myself.

However, I do notice that the "dasdcopy"
command has a "-lfs" option to create a
single file, presumably on output. Not
sure if it can handle a split file on input.

BFN. Paul.




---In hercules-***@yahoogroups.com, <***@...> wrote :

Hi,


Hope this is the right group to post this to; otherwise I'd appreciate it if you can point me in the right direction.


I have some large CKD DASD image files (as detected by the 'file' command).

Each image seems to be split in two files (old OS limitations?), first file is around 2 GB, second file is around 700 MB.


I want to compress these, but when I try to I can only compress the first (biggest) file, and the result is useless.


So, my question is: is there a utility that will allow me to merge the 2 image files into 1 file?

If there isn't, can someone provide with the manual steps to do so?


Thanks in advance.
somitcw@yahoo.com [hercules-390]
2016-02-01 02:42:40 UTC
Permalink
Post by Gonzalo Martin Barrio ***@gmail.com [hercules-390]
Hi,
Hope this is the right group to post this to; otherwise I'd appreciate
it if you can point me in the right direction.
I have some large CKD DASD image files (as detected by the
'file' command).
Each image seems to be split in two files (old OS limitations?),
first file is around 2 GB, second file is around 700 MB.
I want to compress these, but when I try to I can only compress
the first (biggest) file, and the result is useless.
So, my question is: is there a utility that will allow me to merge
the 2 image files into 1 file?
If there isn't, can someone provide with the manual steps to
do so?
Thanks in advance.
How did you compress one?
Was it a Windows file compress?
Or was it one of the Hercules commands?
It is difficult to respond to what you don't post.

I assume that it is a CKD split file and not a CCKD shadow file?

I assume that your current disk supports LargeFileSystems?

I assume that DASDCOPY with -lfs might do what you want?

You could also consider to instead switch from CKD to CCKD ?
Both CKD and CCKD have advantages.

More information might get better help?
lists@openmailbox.org [hercules-390]
2016-02-01 07:32:45 UTC
Permalink
On 31 Jan 2016 18:42:40 -0800
Post by ***@yahoo.com [hercules-390]
Post by Gonzalo Martin Barrio ***@gmail.com [hercules-390]
Hi,
Hope this is the right group to post this to; otherwise I'd appreciate
it if you can point me in the right direction.
I have some large CKD DASD image files (as detected by the
'file' command).
Each image seems to be split in two files (old OS limitations?),
first file is around 2 GB, second file is around 700 MB.
I want to compress these, but when I try to I can only compress
the first (biggest) file, and the result is useless.
So, my question is: is there a utility that will allow me to merge
the 2 image files into 1 file?
If there isn't, can someone provide with the manual steps to
do so?
Thanks in advance.
How did you compress one?
Was it a Windows file compress?
Or was it one of the Hercules commands?
It is difficult to respond to what you don't post.
I assume that it is a CKD split file and not a CCKD shadow file?
I assume that your current disk supports LargeFileSystems?
I assume that DASDCOPY with -lfs might do what you want?
Yes, I believe that is correct. I used it probably in the same situation
the OP asked about and it worked as desired.
Post by ***@yahoo.com [hercules-390]
You could also consider to instead switch from CKD to CCKD ?
Both CKD and CCKD have advantages.
I thought there was a corruption issue with CCKD? Unless you are running on
a tiny box like RPi and simply don't have the disk space it seems like CCKD
is a very bad idea. YMMV.
--
Please do not copy me on mailing list replies. I read the mailing list.
RSA 4096 fingerprint 7940 3F02 16D3 AFEE F2F8 ACAA 557C 4B36 98E4 4D49
kerravon86@yahoo.com.au [hercules-390]
2016-02-01 08:07:40 UTC
Permalink
Post by ***@openmailbox.org [hercules-390]
I thought there was a corruption issue with CCKD?
I've never had a problem, and I've been
running with compressed disks for about
a decade.

If you know of a corruption issue, please
point to the post in Hercules-390 where
someone reported an issue so that we
can see how the developers responded.

Otherwise I don't know what you're
talking about, and I don't think you
should be spreading rumours about
there being corruption issues in
(what exactly - every single version
of Hercules ever released???).
Post by ***@openmailbox.org [hercules-390]
it seems like CCKD is a very bad idea. YMMV.
I believe you need to use CCKD in order
to be able to use shadow files.

Shadow files are fantastic.

BFN. Paul.





---In hercules-***@yahoogroups.com, <***@...> wrote :

On 31 Jan 2016 18:42:40 -0800
Post by ***@openmailbox.org [hercules-390]
Post by Gonzalo Martin Barrio ***@gmail.com [hercules-390]
Hi,
Hope this is the right group to post this to; otherwise I'd appreciate
it if you can point me in the right direction.
I have some large CKD DASD image files (as detected by the
'file' command).
Each image seems to be split in two files (old OS limitations?),
first file is around 2 GB, second file is around 700 MB.
I want to compress these, but when I try to I can only compress
the first (biggest) file, and the result is useless.
So, my question is: is there a utility that will allow me to merge
the 2 image files into 1 file?
If there isn't, can someone provide with the manual steps to
do so?
Thanks in advance.
How did you compress one?
Was it a Windows file compress?
Or was it one of the Hercules commands?
It is difficult to respond to what you don't post.
I assume that it is a CKD split file and not a CCKD shadow file?
I assume that your current disk supports LargeFileSystems?
I assume that DASDCOPY with -lfs might do what you want?
Yes, I believe that is correct. I used it probably in the same situation
the OP asked about and it worked as desired.
Post by ***@openmailbox.org [hercules-390]
You could also consider to instead switch from CKD to CCKD ?
Both CKD and CCKD have advantages.
I thought there was a corruption issue with CCKD? Unless you are running on
a tiny box like RPi and simply don't have the disk space it seems like CCKD
is a very bad idea. YMMV.

--
Please do not copy me on mailing list replies. I read the mailing list.
RSA 4096 fingerprint 7940 3F02 16D3 AFEE F2F8 ACAA 557C 4B36 98E4 4D49
Gerhard Postpischil gerhardp@charter.net [hercules-390]
2016-02-01 08:25:38 UTC
Permalink
Post by ***@yahoo.com.au [hercules-390]
I've never had a problem, and I've been
running with compressed disks for about
a decade.
When I first started using (an early) Hercules with tk3, I used CCKD on
a USB drive on a spare Windows system. I didn't know enough to compress
the files regularly, and they just grew. One day I ran out of disk
space, and lost all changes made to that disk, lost Hercules, and had
the PC crash.

At a minimum any distribution based on CCKD should also include pattern
files (cron, etc. on *nix; ? on Win) to alert the user to do regular
compresses.

Since then I've used CKD on 1TB+ USB drives (and used these for
automatic backup of 70+ disk images), and haven't had any more problems.
And I have the assurance of not running out of disk space when I run
MVS, despite the DSCB1 changes at each access.

Gerhard Postpischil
Bradford, VT
'John P. Hartmann' jphartmann@gmail.com [hercules-390]
2016-02-01 11:18:32 UTC
Permalink
I also had my file system run full. When I killed the errant process
and released space, Hercules recovered without losing any data.
Post by Gerhard Postpischil ***@charter.net [hercules-390]
Post by ***@yahoo.com.au [hercules-390]
I've never had a problem, and I've been
running with compressed disks for about
a decade.
When I first started using (an early) Hercules with tk3, I used CCKD on
a USB drive on a spare Windows system. I didn't know enough to compress
the files regularly, and they just grew. One day I ran out of disk
space, and lost all changes made to that disk, lost Hercules, and had
the PC crash.
At a minimum any distribution based on CCKD should also include pattern
files (cron, etc. on *nix; ? on Win) to alert the user to do regular
compresses.
Since then I've used CKD on 1TB+ USB drives (and used these for
automatic backup of 70+ disk images), and haven't had any more problems.
And I have the assurance of not running out of disk space when I run
MVS, despite the DSCB1 changes at each access.
Gerhard Postpischil
Bradford, VT
somitcw@yahoo.com [hercules-390]
2016-02-01 12:47:59 UTC
Permalink
I also had my file system run full. When I killed the errant process
and released space, Hercules recovered without losing any data.
There was an issue with some specific device numbers.
CCKD code would divide an internal number and sometimes
have a zero remainder that wasn't handles properly.
Until it was fixed, I skipped that device address.

Shadow files might be okay if needed and properly managed
but I never use them.

If someone has space for a CKD image, they should be able
to avoid running out of space with a CCKD image?
Perhaps shadow files could help managing disk space?
Or have the start hercules .bat check space?
Gonzalo Martin Barrio gonzalobarrio@gmail.com [hercules-390]
2016-02-01 16:06:46 UTC
Permalink
Thank you all for your replies.
I'll go ahead and try dasdcopy -lfs and see how that works.

@somitcw
My bad; when I said I was compressing the files, I meant CKD>CCKD
And yes, to the best of my knowledge it is a split CKD file, not a shadow
file (though I guess I'll find out when I try the dasdcopy)
Post by ***@yahoo.com [hercules-390]
I also had my file system run full. When I killed the errant process
and released space, Hercules recovered without losing any data.
There was an issue with some specific device numbers.
CCKD code would divide an internal number and sometimes
have a zero remainder that wasn't handles properly.
Until it was fixed, I skipped that device address.
Shadow files might be okay if needed and properly managed
but I never use them.
If someone has space for a CKD image, they should be able
to avoid running out of space with a CCKD image?
Perhaps shadow files could help managing disk space?
Or have the start hercules .bat check space?
Mike Schwab Mike.A.Schwab@gmail.com [hercules-390]
2016-02-01 18:38:59 UTC
Permalink
When you copy CKD disk to CCKD, your output file should be smaller. If the
CCKD disk fills up (32 bit limit), delete the partial file, create a shadow
file, and continue your restore not replacing files.

On Mon, Feb 1, 2016 at 10:06 AM, Gonzalo Martin Barrio
Post by Gonzalo Martin Barrio ***@gmail.com [hercules-390]
Thank you all for your replies.
I'll go ahead and try dasdcopy -lfs and see how that works.
@somitcw
My bad; when I said I was compressing the files, I meant CKD>CCKD
And yes, to the best of my knowledge it is a split CKD file, not a shadow
file (though I guess I'll find out when I try the dasdcopy)
Post by ***@yahoo.com [hercules-390]
I also had my file system run full. When I killed the errant process
and released space, Hercules recovered without losing any data.
There was an issue with some specific device numbers.
CCKD code would divide an internal number and sometimes
have a zero remainder that wasn't handles properly.
Until it was fixed, I skipped that device address.
Shadow files might be okay if needed and properly managed
but I never use them.
If someone has space for a CKD image, they should be able
to avoid running out of space with a CCKD image?
Perhaps shadow files could help managing disk space?
Or have the start hercules .bat check space?
--
Mike A Schwab, Springfield IL USA
Where do Forest Rangers go to get away from it all?
'Dave Wade' dave.g4ugm@gmail.com [hercules-390]
2016-02-01 08:38:01 UTC
Permalink
Post by ***@openmailbox.org [hercules-390]
asked about and it worked as desired.
Post by ***@yahoo.com [hercules-390]
You could also consider to instead switch from CKD to CCKD ?
Both CKD and CCKD have advantages.
I thought there was a corruption issue with CCKD? Unless you are running on
a tiny box like RPi and simply don't have the disk space it seems like
CCKD is a
Post by ***@openmailbox.org [hercules-390]
very bad idea. YMMV.
It can be, but if you want larger than 2Gb then I believe it's the only
choice...
Post by ***@openmailbox.org [hercules-390]
--
Please do not copy me on mailing list replies. I read the mailing list.
RSA 4096 fingerprint 7940 3F02 16D3 AFEE F2F8 ACAA 557C 4B36 98E4 4D49
Dave
lists@openmailbox.org [hercules-390]
2016-02-01 09:13:46 UTC
Permalink
On Mon, 1 Feb 2016 08:38:01 -0000
Post by ***@openmailbox.org [hercules-390]
Post by ***@openmailbox.org [hercules-390]
asked about and it worked as desired.
Post by ***@yahoo.com [hercules-390]
You could also consider to instead switch from CKD to CCKD ?
Both CKD and CCKD have advantages.
I thought there was a corruption issue with CCKD? Unless you are running
on
Post by ***@openmailbox.org [hercules-390]
a tiny box like RPi and simply don't have the disk space it seems like
CCKD is a
Post by ***@openmailbox.org [hercules-390]
very bad idea. YMMV.
It can be, but if you want larger than 2Gb then I believe it's the only
choice...
No, as I said I used it to combine the 2G and 700M files the OP is probably
talking about. If you use -lfs as somitcw suggested it creates a 2.7G file
which works correctly with Hercules and the utilities.
Tony Harminc tharminc@gmail.com [hercules-390]
2016-02-01 18:03:46 UTC
Permalink
Post by ***@openmailbox.org [hercules-390]
I thought there was a corruption issue with CCKD? Unless you are running on
a tiny box like RPi and simply don't have the disk space it seems like CCKD
is a very bad idea. YMMV.
CCKD is no more subject to corruption in the underlying (UNIX or
Windows or...) file system than CKD. If you pull the rug out from
under any application database file, you are likely to have problems.
CCKD does contain some very sophisticated code to try to recover from
such errors, both automatically and under user control.

Tony H.
lists@openmailbox.org [hercules-390]
2016-02-01 18:21:46 UTC
Permalink
On Mon, 1 Feb 2016 13:03:46 -0500
Post by Tony Harminc ***@gmail.com [hercules-390]
Post by ***@openmailbox.org [hercules-390]
I thought there was a corruption issue with CCKD? Unless you are
running on a tiny box like RPi and simply don't have the disk space it
seems like CCKD is a very bad idea. YMMV.
CCKD is no more subject to corruption in the underlying (UNIX or
Windows or...) file system than CKD. If you pull the rug out from
under any application database file, you are likely to have problems.
CCKD does contain some very sophisticated code to try to recover from
such errors, both automatically and under user control.
I seem to remember reading about a bug in the cckd code. It had nothing to
do with the host filesystem IIRC. When I have some time I'll try to find it
if the yahoo group is public.
--
Please do not copy me on mailing list replies. I read the mailing list.
RSA 4096 fingerprint 7940 3F02 16D3 AFEE F2F8 ACAA 557C 4B36 98E4 4D49
'Dave Wade' dave.g4ugm@gmail.com [hercules-390]
2016-02-01 08:48:34 UTC
Permalink
Post by Gonzalo Martin Barrio ***@gmail.com [hercules-390]
I have some large CKD DASD image files (as detected by the 'file' command).
Each image seems to be split in two files (old OS limitations?), first file is around 2 GB, second file is around 700 MB.
No, this is a limitation of the CKD structure.
Post by Gonzalo Martin Barrio ***@gmail.com [hercules-390]
I want to compress these, but when I try to I can only compress the first (biggest) file, and the result is useless.
So, my question is: is there a utility that will allow me to merge the 2 image files into 1 file?
If there isn't, can someone provide with the manual steps to do so?
DASDCOPY will let you do this, but generally you will still end up with multiple file as the 2GB limit is to do with the way CKD is structured.
Note you need to pass both file names to DASDCOPY
Post by Gonzalo Martin Barrio ***@gmail.com [hercules-390]
Thanks in advance.
Dave
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