Re: File size difference between PF and *SAVF

Larry, I will not often contradict you - still, I think this is not correct.

If I do any SAV* command, DTACPR has *NO, *YES, *LOW, *MEDIUM, & *HIGH. The help text has all this.

*YES - if to SAVF or optical, it uses *LOW, unless it is optical DVD.

I am not sure how it USED to be - I found that *YES to *SAVF could easily be bigger then *LOW - but that was some years ago.

*LOW - uses the SNA algorithm - probably used to used for *YES

*MEDIUM - uses the TERSE algorithm

*HIGH - uses the LZ1 algorithm

The more the compression, the smaller the result and the longer to get it. I did some test runs several years ago - I found that *HIGH did not provide enough benefit in size to justify the extra time, in most cases.

So for casual everyday stuff, I always use DTACPR(*MEDIUM).

I wonder if I didn't publish my findings somewhere on MIDRANGE-L - I've been here around 20 years, would you believe?

HTH
Vern

On 4/23/2015 4:15 PM, DrFranken wrote:

I think you can only specify *YES for save files which equates to *MED. For Virtual Optical you get *LOW *MED and *HIGH. Remember too that you can SAVACCPTH(*NO) as well which can save a bit on the space but at a penalty on restore.

Forgive typos-reply on an airplane and I'm too cheap to purchase the wifi.


- Larry "DrFranken" Bolhuis

www.frankeni.com
www.iDevCloud.com
www.iInTheCloud.com

On 4/23/2015 3:07 PM, Scott Klement wrote:

Yes, save files will always be bigger than the original PF unless you
use compression.

Try using DTACPR(*HIGH) (or *YES on older releases) when running the
SAVxxx command to create your save file. This enables compression that
can significantly reduce the size of the save file.


On 4/23/2015 2:00 PM, John McKee wrote:

This may be old stuff. Just noticed today. I had to transfer a large PF
from remote 520 to local. Learned, in the past, that FTP does not retain
file definition, so created a save file and transferred it. Paranoia
about
file content led to extracting the single file and spot checking.

Never had the opportunity to do this before. I thought a save file might
be a little smaller than original physical file. Maybe somewhere, but
not
in this case.

Save file size is 18586152960
Physical file size is 12014727168

I expected the save file to be a little larger, to acomodate field
information. I wasn't aware the difference could be this much. I did
not
specify compression on the v5r3 system.

Does the size difference seem unusual, or is that the norm?

John McKee