Joined: 13 Dec 2006 Posts: 101 Topics: 4 Location: india
Posted: Mon Oct 29, 2007 2:46 am Post subject:
vkphani, thanks for that idea
But, i would like to know how to calculate myself.
Expat
Thanks for your logical solution.
The only doubt i have is, what are these 2 values 27998 and 60 in the below quote.
Guess 60 is LRECL, but not clear about another one.
Quote:
27998 / 60 = 466.3333 = 466 records per block = BLKSIZE=27960
Joined: 13 Dec 2006 Posts: 101 Topics: 4 Location: india
Posted: Mon Oct 29, 2007 4:33 am Post subject:
vkphani
Thanks for that link. All my doubts are cleared now.
So,27998 is the constant that we have to consider for 3390-n device.
Cicsguy, you are trying to tell something, but i don't understand as to what ?
Hope you did not get confused with 27998 and 27960 _________________ cHEERs
krisprems
Joined: 13 Dec 2006 Posts: 101 Topics: 4 Location: india
Posted: Mon Oct 29, 2007 5:30 am Post subject:
vkphani
Quote:
But not sure as to how this constant got created.
Come on, in the link that you gave first part is the explanation as to how that constant got created.... see this below quote from the link you provided
Quote:
The largest blocksize you can define is 32,760, which is good for tapes,but it is mere waste on DASD, as 55,996 - 32760 = 23,236 bytes left over,and because tracks can't be shared between other files, that leftover space would just be wasted.
So,55,996/2=27,998,which is half-track blocking,the most space-efficient blocksize to use on 3390's.
CICS Guy
Quote:
Since you can't have a third of a record in a block, 60 * 433 = 27960........
OK, you are pointing on 27960... but my question was on 27998.. any ways, thank u _________________ cHEERs
krisprems
The largest blocksize you can define is 32,760, which is good for tapes,but it is mere waste on DASD, as 55,996 - 32760 = 23,236 bytes left over,and because tracks can't be shared between other files, that leftover space would just be wasted.
So,55,996/2=27,998,which is half-track blocking,the most space-efficient blocksize to use on 3390's.
so, if it's not clear from earlier posts - a track on a 3390-n is ~56KB. The largest size a block can be is 3~2KB.
If you select a block size of 32KB, you waste ~24KB of space on each track.
Quote:
The largest blocksize you can define is 32,760, which is good for tapes,but it is mere waste on DASD, as 55,996 - 32760 = 23,236 bytes left over,and because tracks can't be shared between other files, that leftover space would just be wasted.
So,55,996/2=27,998,which is half-track blocking,the most space-efficient blocksize to use on 3390's.
It's wasted if you don't have a variable record length, IIRC? If you have variable length records, your blocks are variable length too, or something like that...
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what are these 2 values 27998 and 60 in the below quote.
