IBM Mainframe Forum

by **samb01** » Thu Jul 09, 2015 1:03 pm

Hello,

can kwnow exactly the real size of the extent of a datset ?

For exemple,

i have this dataset :

- Enter "/" to select action Tracks %Used XT
---------------------------------------------------------------------
P.FDRGDPP.CGTDS.G0020V00 10635 99 11

The informations about this dataset are :

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Command ===>
More:
Data Set Name . . . . : P.FDRGDPP.CGTDS.G0020V00

General Data Current Allocation
Management class . . : **None** Allocated cylinders : 41,831
Storage class . . . : SCDBDUM Allocated extents . : 649
Volume serial . . . : PDUM14 +
Device type . . . . : 3390
Data class . . . . . : DCKOMP1
Organization . . . : PS Current Utilization
Record format . . . : VB Used cylinders . . : 41,786
Record length . . . : 27994 Used extents . . . : 444
Block size . . . . : 27998
1st extent cylinders: 650
Secondary cylinders : 300 Dates
Data set name type : EXTENDED Creation date . . . : 2015/06/30
Referenced date . . : 2015/07/05
Expiration date . . : ***None***
SMS Compressible . : YES

because there are 59 volume allocated

How can we know the real size of an extent ?

For the other 58 volume of this datset, the allocation is the same :

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DSLIST - Data Sets on volume PDUM* Row 1 of 59
Command ===> Scroll ===> CSR

Command - Enter "/" to select action Tracks %Used XT
------------------------------------------------------------------------------
P.FDRGDPP.CGTDS.G0020V00 10635 99 11
P.FDRGDPP.CGTDS.G0020V00 10635 99 11
P.FDRGDPP.CGTDS.G0020V00 10635 99 11
P.FDRGDPP.CGTDS.G0020V00 10635 99 11
P.FDRGDPP.CGTDS.G0020V00 10635 99 11
P.FDRGDPP.CGTDS.G0020V00 10635 99 11
P.FDRGDPP.CGTDS.G0020V00 10635 99 11
P.FDRGDPP.CGTDS.G0020V00 10635 99 11
P.FDRGDPP.CGTDS.G0020V00 10635 99 11
P.FDRGDPP.CGTDS.G0020V00 10635 99 11
P.FDRGDPP.CGTDS.G0020V00 10635 99 11
P.FDRGDPP.CGTDS.G0020V00 10635 99 11

etc...

I think teh Secondary cylinders : 300 is too much.....

by **steve-myers** » Thu Jul 09, 2015 4:21 pm

Unfortunately you are asking a question for which there is no simple answer.

In the initial allocation on the first volume, in theory, though not always in actual fact, the system will allocate the requested space, but it may be divided into up to 5 physical extents. As necessary, the system will allocate additional extents, up to 16 total extents - and sometimes more. Each additional extent will have the space specified in your secondary allocation. If the volume runs out of space, there may be fewer extents.
In subsequent volumes, the initial allocation will be the size of the secondary allocation, not the primary allocation as specified in JCL. Additional extents, sized with the secondary allocation, will be allocated as with the initial volume.

Sadly, there is no simple way to determine the actual allocation of an extent. The only tool I am certain is available in every site is IEHLIST. The LISTVTOC FORMAT command will list the extents, like this

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NO LOW(C-H) HIGH(C-H)
0 386 0 389 14
3 127 0 128 14

Each line in the IEHLIST report has 3 extents, I just showed the first extent on a line, but 2 lines. The extent on the first line has 4 cylinders. The extent on the second line has 2 cylinders. Your site may have more usable tools. For example, a private tool I use shows

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---NO--RELTRK--START CCHH--END CCHH--TRACKS
1 00000 01820000 0185000E 60
2 0003C 00860000 0086000E 15
3 0004B 01AC0000 01AD000E 30
4 00069 007F0000 0080000E 30
5 00087 012C0000 012D000E 30

This is the same data set; it shows the extents in hexadecimal rather than decimal in IEHLIST; and it calculates the number of tracks in the extent.

by **samb01** » Thu Jul 09, 2015 5:28 pm

Hello steve-myers,

if i anderstand the different extent hev not the same size...

It seems to be in my case (the same size).

You have to know that we use a STORCLAS with Guaranteed Space.

So i think the fisrt extent is the primary allocation (650 cyl *15) = 9750 trks.

But the allocation of the dataset in one volume takes : 10635 trks :

Select all

------------------------------------------------------------------------------
P.FDRGDPP.CGTDS.G0020V00 10635 99 11
P.FDRGDPP.CGTDS.G0020V00 10635 99 11
P.FDRGDPP.CGTDS.G0020V00 10635 99 11
P.FDRGDPP.CGTDS.G0020V00 10635 99 11

so 10635 - 9750 = 885 trks

ANd we can see that there are 11 extent. So (by removing the thirst extent) i calculate :

885 / 10 = 88.5 trks

88.5 trks / 15 = 5.9 cyl

So i calculate there are 5,9 cyl by extent in each volume.

Is it right ?

Here is the allocation in the JCL :

DISP=(,CATLG,DELETE),DATACLAS=DCKOMP1,
SPACE=(CYL,(650,300),RLSE),VOL=(,,,59),
DCB=(RECFM=VB,LRECL=27994,BLKSIZE=27998)

by **enrico-sorichetti** » Thu Jul 09, 2015 7:23 pm

You have to know that we use a STORCLAS with Guaranteed Space

and You should know that ...
The storage class attribute of GUARANTEED SPACE allows the volumes on which a data set resides to be chosen explicitly when that data set is created.
and has nothing to do with the extents thing.

by **steve-myers** » Thu Jul 09, 2015 9:14 pm

samb01 wrote:...if i anderstand the different extent hev not the same size...

It seems to be in my case (the same size).

Don't bet on it. In fact, though I have not attempted to examine your analysis in detail, since you seem to be coming up with fractions of a cylinder, it would seem not all of your extents are the same size. You have to analyze each data set element on each volume independently.

Space analysis of a volume is tricky.

One track, cylinder 0, track 0, is reserved for the volume label and IPL text. It is not allocated as a data set and is not free space. The volume label is a small record at cylinder 0, track 0, record 3. Records 1 and 2 ( and record 4 and higher) are IPL text. In addition to defining the volume serial of the volume, the volume label has the address of the first track of the VTOC.

The VTOC, while it is not a data set, is treated as a data set by most, if not all, volume analyzer utilities. Many times the VTOC is allocated as a full cylinder or multiple cylinder "data set," though there is no requirement for this, and its size and location vary by the whims of the storage management group that prepared the volume.

The VTOC index is a data set. More often than not its size and location are determined by the ICKDSF utility used to prepare volumes. It is rarely as much as a cylinder.

In other words, free space on a volume, as measured in tracks, is not always in full cylinders.

by **steve-myers** » Sun Jul 19, 2015 8:23 pm

samb01 wrote:... I think teh Secondary cylinders : 300 is too much.....

Maybe.

In my earlier discussion I mentioned a limit of 16 extents per data set per volume.

However, there is another limit. Most data sets have a limit of 65536 tracks per data set per volume. Beginning with z/OS 1.7 this limit can be exceeded if you specify DSNTYPE=LARGE and there is enough free space that the allocation can be done. To get more than 16 extents you need to specify an "extended format" data set with DSNTYPE=EXTREQ. An extended format data set can also have more than 65536 tracks.

Now let's return to a secondary allocation of 300 cylinders. For most sites 300 cylinders is 4500 tracks - 300 cylinders x 15 tracks / cylinder.

Now 65536 / 4500 = 14.56 extents, so allocation will give you 14 extents. So, provided there is enough free space, you will get 4200 cylinders in 14 extents with basic allocation.

Now, I don't have the luxury of 59 volumes (though they are all 3390-9), but ...

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(EXTENTS 07/19/15 06.51) D A T A S E T E X T E N T S 2015/07/19 09:28 PAGE 1

EXTENTS FOR USERID.BIG.OUTPUT
VOLUME EXTENT START END TRACKS
VOL016 1 02620000 0458000E 7545
2 04590000 0584000E 4500
3 05850000 06B0000E 4500
4 06B10000 07DC000E 4500
5 07DD0000 0908000E 4500
6 09090000 0A34000E 4500
7 0A350000 0B60000E 4500
8 0B610000 0C8C000E 4500
9 0C8D0000 0DB8000E 4500
10 01250000 0250000E 4500
11 0F020000 102D000E 4500
12 102E0000 1159000E 4500
13 115A0000 1285000E 4500
VOL014 1 04E10000 060C000E 4500
2 060D0000 0738000E 4500
3 07390000 0864000E 4500
4 08650000 0990000E 4500
5 0A9E0000 0BC9000E 4500
6 0BCA0000 0CF5000E 4500
7 0CF60000 0E21000E 4500
8 0E220000 0F4D000E 4500
9 0F4E0000 1079000E 4500
10 107A0000 11A5000E 4500
11 11A60000 12D1000E 4500
12 12D20000 13FD000E 4500
13 13FE0000 1529000E 4500
14 152A0000 1655000E 4500
VOL025 1 018D0000 02B8000E 4500
2 03310000 045C000E 4500
3 045D0000 0588000E 4500
4 05890000 06B4000E 4500
5 06B50000 07E0000E 4500
6 07E10000 090C000E 4500
7 090D0000 0A38000E 4500
8 0A390000 0B64000E 4500
9 0B650000 0C90000E 4500
10 0C910000 0DBC000E 4500
11 0DBD0000 0EE8000E 4500
12 0EE90000 1014000E 4500
13 10150000 1140000E 4500
14 11410000 126C000E 4500
VOL020 1 03D80000 0503000E 4500
2 05040000 062F000E 4500
3 06300000 075B000E 4500
4 075C0000 0887000E 4500
5 08880000 09B3000E 4500
6 09B40000 0ADF000E 4500
7 0AE00000 0C0B000E 4500
8 0C0C0000 0D37000E 4500
9 0D380000 0E63000E 4500
10 0E640000 0F8F000E 4500
11 0F900000 10BB000E 4500
12 10BC0000 11E7000E 4500
13 11E80000 1313000E 4500
14 13140000 143F000E 4500
VOL013 1 03BA0000 04E5000E 4500
2 04E60000 0611000E 4500
3 06120000 073D000E 4500
4 073E0000 0869000E 4500
5 086A0000 0995000E 4500
6 09960000 0AC1000E 4500
7 0AC20000 0BED000E 4500
8 0BEE0000 0D19000E 4500
9 0D1A0000 0E45000E 4500
10 0F270000 1052000E 4500
11 10530000 117E000E 4500
12 117F0000 12AA000E 4500
13 12AB0000 13D6000E 4500
14 13D70000 1502000E 4500
VOL024 1 02460000 0371000E 4500
2 03720000 049D000E 4500
3 049E0000 05C9000E 4500
4 05CA0000 06F5000E 4500
5 06F60000 0821000E 4500
6 08220000 094D000E 4500
7 094E0000 0A79000E 4500
8 0A7A0000 0BA5000E 4500
9 0BA60000 0CD1000E 4500
10 0CD20000 0DFD000E 4500
11 0DFE0000 0F29000E 4500
12 0F2A0000 1055000E 4500
13 10560000 1181000E 4500
14 11820000 12AD000E 4500
VOL01C 1 03F90000 0524000E 4500
2 05250000 0650000E 4500
3 06E00000 080B000E 4500
4 08A90000 09D4000E 4500
5 09D50000 0B00000E 4500
6 0B010000 0C2C000E 4500
7 0CA20000 0DCD000E 4500
8 0E130000 0F3E000E 4500
9 0F3F0000 106A000E 4500
10 106B0000 1196000E 4500
11 11970000 12C2000E 4500
12 12C30000 13EE000E 4500
13 13EF0000 151A000E 4500
14 151B0000 1646000E 4500
VOL01B 1 02030000 032E000E 4500
2 04E90000 0614000E 4500
3 06150000 0740000E 4500
4 08260000 0951000E 4500
5 09520000 0A7D000E 4500
6 0A8B0000 0BB6000E 4500
7 0BB70000 0CE2000E 4500
8 0CE30000 0E0E000E 4500
9 0E0F0000 0F3A000E 4500
10 0F3B0000 1066000E 4500
11 10670000 1192000E 4500
12 11930000 12BE000E 4500
13 12BF0000 13EA000E 4500
14 13EB0000 1516000E 4500
VOL015 1 01AE0000 02D9000E 4500
2 02DA0000 0405000E 4500
3 04060000 0531000E 4500
4 05320000 065D000E 4500
5 065E0000 0789000E 4500
6 078A0000 08B5000E 4500
7 08B60000 09E1000E 4500
8 0A9A0000 0BC5000E 4500
9 0CF10000 0E1C000E 4500
10 0E1D0000 0F48000E 4500
11 0F490000 1074000E 4500
12 10750000 11A0000E 4500
13 11A10000 12CC000E 4500
14 12CD0000 13F8000E 4500
VOL01F 1 00D10000 01FC000E 4500
2 01FD0000 0328000E 4500
3 03290000 0454000E 4500
4 04550000 0580000E 4500
5 067D0000 07A8000E 4500
6 07A90000 08D4000E 4500
7 09E20000 0B0D000E 4500
8 0B0E0000 0C39000E 4500
9 0C3A0000 0D65000E 4500
10 0D660000 0E91000E 4500
11 0E920000 0FBD000E 4500
12 0FBE0000 10E9000E 4500
13 10EA0000 1215000E 4500
14 12160000 1341000E 4500
VOL010 1 01DB0000 0306000E 4500
2 03070000 0432000E 4500
3 04330000 055E000E 4500
4 055F0000 068A000E 4500
5 068B0000 07B6000E 4500
6 07B70000 08E2000E 4500
7 08E30000 0A0E000E 4500
8 0A0F0000 0B3A000E 4500
9 0BAC0000 0CD7000E 4500
10 0CD80000 0E03000E 4500
11 0E040000 0F2F000E 4500
12 0F300000 105B000E 4500
13 12430000 136E000E 4500
14 136F0000 149A000E 4500
VOL027 1 021B0000 0346000E 4500
2 03470000 0472000E 4500
3 04730000 059E000E 4500
4 059F0000 06CA000E 4500
5 06CB0000 07F6000E 4500
6 07F70000 0922000E 4500
7 09230000 0A4E000E 4500
8 0A4F0000 0B7A000E 4500
9 0B7B0000 0CA6000E 4500
10 0D7C0000 0EA7000E 4500
11 0EA80000 0FD3000E 4500
12 0FD40000 10FF000E 4500
13 11000000 122B000E 4500
14 122C0000 1357000E 4500
VOL033 1 05910000 06BC000E 4500
2 07350000 0860000E 4500
3 08610000 098C000E 4500
4 098D0000 0AB8000E 4500
5 0AB90000 0BE4000E 4500
6 0BE50000 0D10000E 4500
7 0D110000 0E3C000E 4500
8 0E3D0000 0F68000E 4500
9 0F690000 1094000E 4500
10 10950000 11C0000E 4500
11 11C10000 12EC000E 4500
12 12ED0000 1418000E 4500
13 14190000 1544000E 4500
14 15450000 1670000E 4500
VOL032 1 03390000 0464000E 4500
2 04650000 0590000E 4500
3 05910000 06BC000E 4500
4 06BD0000 07E8000E 4500
5 07E90000 0914000E 4500
6 09150000 0A40000E 4500
7 0A410000 0B6C000E 4500
8 0B6D0000 0C98000E 4500
9 0C990000 0DC4000E 4500
10 0DC50000 0EF0000E 4500
11 0EF10000 101C000E 4500
12 101D0000 1148000E 4500
13 11490000 1274000E 4500
14 12750000 13A0000E 4500
VOL018 1 04670000 0592000E 4500
2 05930000 06BE000E 4500
3 06BF0000 07EA000E 4500
4 07EB0000 0916000E 4500
5 0A1C0000 0B47000E 4500
6 0B930000 0CBE000E 4500
7 0CBF0000 0DEA000E 4500
8 0DEB0000 0F16000E 4500
9 0F170000 1042000E 4500
10 10640000 118F000E 4500
11 126B0000 1396000E 4500
12 13970000 14C2000E 4500
13 14C30000 15EE000E 4500
14 15EF0000 171A000E 4500
VOL019 1 01E70000 0312000E 4500
2 03130000 043E000E 4500
3 043F0000 056A000E 4500
4 056B0000 0696000E 4500
5 06970000 07C2000E 4500
6 07C30000 08EE000E 4500
7 08EF0000 0A1A000E 4500
8 0A1B0000 0B46000E 4500
9 0B470000 0C72000E 4500
10 0C730000 0D9E000E 4500
11 0D9F0000 0ECA000E 4500
12 0ECB0000 0FF6000E 4500
13 11690000 1294000E 4500
14 12950000 13C0000E 4500
VOL011 1 03300000 045B000E 4500
2 045C0000 0587000E 4500
3 05880000 06B3000E 4500
4 06B40000 07DF000E 4500
5 07E00000 090B000E 4500
6 090C0000 0A37000E 4500
7 0B0C0000 0C37000E 4500
8 0C380000 0D63000E 4500
9 0D990000 0EC4000E 4500
10 0EC50000 0FF0000E 4500
11 0FF10000 111C000E 4500
12 111D0000 1248000E 4500
13 12490000 1374000E 4500
14 13750000 14A0000E 4500
VOL028 1 01C70000 02F2000E 4500
2 02F30000 041E000E 4500
3 041F0000 054A000E 4500
4 054B0000 0676000E 4500
5 06770000 07A2000E 4500
6 07A30000 08CE000E 4500
7 08CF0000 09FA000E 4500
8 09FB0000 0B26000E 4500
9 0B270000 0C52000E 4500
10 0C530000 0D7E000E 4500
11 0D7F0000 0EAA000E 4500
12 0EAB0000 0FD6000E 4500
13 0FD70000 1102000E 4500
14 11030000 122E000E 4500
VOL01A 1 019D0000 02C8000E 4500
2 02C90000 03F4000E 4500
3 03F50000 0520000E 4500
4 05F30000 071E000E 4500
5 071F0000 084A000E 4500
6 084B0000 0976000E 4500
7 09770000 0AA2000E 4500
8 0C420000 0D6D000E 4500
9 0D6E0000 0E99000E 4500
10 0E9A0000 0FC5000E 4500
11 0FC60000 10F1000E 4500
12 10F20000 121D000E 4500
13 121E0000 1349000E 4500
14 134A0000 1475000E 4500
VOL01E 1 047C0000 05A7000E 4500
2 05A80000 06D3000E 4500
3 06D40000 07FF000E 4500
4 08000000 092B000E 4500
5 092C0000 0A57000E 4500
6 0A580000 0B83000E 4500
7 0B840000 0CAF000E 4500
8 0CBB0000 0DE6000E 4500
9 0DE70000 0F12000E 4500
10 0F130000 103E000E 4500
11 103F0000 116A000E 4500
12 12470000 1372000E 4500
13 13730000 149E000E 4500
14 149F0000 15CA000E 4500
VOL030 1 03950000 04C0000E 4500
2 04C10000 05EC000E 4500
3 05ED0000 0718000E 4500
4 07190000 0844000E 4500
5 08450000 0970000E 4500
6 09710000 0A9C000E 4500
7 0A9D0000 0BC8000E 4500
8 0BC90000 0CF4000E 4500
9 0CF50000 0E20000E 4500
10 0E210000 0F4C000E 4500
11 0F4D0000 1078000E 4500
12 10790000 11A4000E 4500
13 11A50000 12D0000E 4500
14 12D10000 13FC000E 4500
VOL035 1 03240000 044F000E 4500
2 04500000 057B000E 4500
3 057C0000 06A7000E 4500
4 06A80000 07D3000E 4500
5 07D40000 08FF000E 4500
6 09000000 0A2B000E 4500
7 0A2C0000 0B57000E 4500
8 0B580000 0C83000E 4500
9 0C840000 0DAF000E 4500
10 0DB00000 0EDB000E 4500
11 0EDC0000 1007000E 4500
12 10080000 1133000E 4500
13 11340000 125F000E 4500
14 12600000 138B000E 4500
VOL023 1 02980000 03C3000E 4500
2 03C40000 04EF000E 4500
3 04F00000 061B000E 4500
4 061C0000 0747000E 4500
5 07480000 0873000E 4500
6 08740000 099F000E 4500
7 09A00000 0ACB000E 4500
8 0ACC0000 0BF7000E 4500
9 0BF80000 0D23000E 4500
10 0D240000 0E4F000E 4500
11 0E500000 0F7B000E 4500
12 0F7C0000 10A7000E 4500
13 10A80000 11D3000E 4500
14 11D40000 12FF000E 4500
VOL01D 1 06300000 075B000E 4500
2 075C0000 0887000E 4500
3 08880000 09B3000E 4500
4 09B40000 0ADF000E 4500
5 0C220000 0D4D000E 4500
6 0D4E0000 0E79000E 4500
7 0EB80000 0FE3000E 4500
8 0FE40000 110F000E 4500
9 11100000 123B000E 4500
10 123C0000 1367000E 4500
11 13680000 1493000E 4500
12 14940000 15BF000E 4500
13 15C00000 16EB000E 4500
14 16EC0000 1817000E 4500
VOL034 1 01470000 0272000E 4500
2 02730000 039E000E 4500
3 039F0000 04CA000E 4500
4 04CB0000 05F6000E 4500
5 05F70000 0722000E 4500
6 07230000 084E000E 4500
7 084F0000 097A000E 4500
8 097B0000 0AA6000E 4500
9 0AA70000 0BD2000E 4500
10 0BD30000 0CFE000E 4500
11 0CFF0000 0E2A000E 4500
12 0E2B0000 0F56000E 4500
13 0F570000 1082000E 4500
14 10830000 11AE000E 4500
VOL012 1 014A0000 0275000E 4500
2 02760000 03A1000E 4500
3 03A20000 04CD000E 4500
4 05350000 0660000E 4500
5 06610000 078C000E 4500
6 078D0000 08B8000E 4500
7 08B90000 09E4000E 4500
8 09E50000 0B10000E 4500
9 0B110000 0C3C000E 4500
10 0DCB0000 0EF6000E 4500
11 0EF70000 1022000E 4500
12 10230000 114E000E 4500
13 114F0000 127A000E 4500
14 127B0000 13A6000E 4500
VOL031 1 02EF0000 041A000E 4500
2 041B0000 0546000E 4500
3 05470000 0672000E 4500
4 06730000 079E000E 4500
5 079F0000 08CA000E 4500
6 08CB0000 09F6000E 4500
7 09F70000 0B22000E 4500
8 0B230000 0C4E000E 4500
9 0C4F0000 0D7A000E 4500
10 0D7B0000 0EA6000E 4500
11 0EA70000 0FD2000E 4500
12 0FD30000 10FE000E 4500
13 10FF0000 122A000E 4500
14 122B0000 1356000E 4500
VOL026 1 03DE0000 0509000E 4500
2 085C0000 0987000E 4500
3 09880000 0AB3000E 4500
4 0AB40000 0BDF000E 4500
5 0BE00000 0D0B000E 4500
6 0D0C0000 0E37000E 4500
7 0E380000 0F63000E 4500
8 0F640000 108F000E 4500
9 10900000 11BB000E 4500
10 11BC0000 12E7000E 4500
11 12E80000 1413000E 4500
12 14140000 153F000E 4500
13 15400000 166B000E 4500
14 166C0000 1797000E 4500
VOL029 1 01B40000 02DF000E 4500
2 02E00000 040B000E 4500
3 040C0000 0537000E 4500
4 05380000 0663000E 4500
5 06640000 078F000E 4500
6 07900000 08BB000E 4500
7 08BC0000 09E7000E 4500
8 09E80000 0B13000E 4500
9 0B140000 0C3F000E 4500
10 0C400000 0D6B000E 4500
11 0D6C0000 0E97000E 4500
12 0E980000 0FC3000E 4500
13 0FC40000 10EF000E 4500
14 10F00000 121B000E 4500
VOL021 1 02230000 034E000E 4500
2 034F0000 047A000E 4500
3 047B0000 05A6000E 4500
4 05A70000 06D2000E 4500
5 06D30000 07FE000E 4500
6 07FF0000 092A000E 4500
7 092B0000 0A56000E 4500
8 0A570000 0B82000E 4500
9 0B830000 0CAE000E 4500
10 0CAF0000 0DDA000E 4500
11 0DDB0000 0F06000E 4500
12 0F070000 1032000E 4500
13 10330000 115E000E 4500
14 115F0000 128A000E 4500
VOL022 1 03450000 0470000E 4500
2 04710000 059C000E 4500
3 059D0000 06C8000E 4500
4 06C90000 07F4000E 4500
5 07F50000 0920000E 4500
6 09210000 0A4C000E 4500
7 0A4D0000 0B78000E 4500
8 0B790000 0CA4000E 4500
9 0CA50000 0DD0000E 4500
10 0DD10000 0EFC000E 4500
11 0EFD0000 1028000E 4500
12 10290000 1154000E 4500
13 11550000 1280000E 4500
14 12810000 13AC000E 4500
VOL017 1 02760000 03A1000E 4500
2 03A20000 04CD000E 4500
3 04CE0000 05F9000E 4500
4 05FA0000 0725000E 4500
5 07260000 0851000E 4500
6 08520000 097D000E 4500
7 097E0000 0AA9000E 4500
8 0BAA0000 0CD5000E 4500
9 0CD60000 0E01000E 4500
10 0E020000 0F2D000E 4500
11 0F2E0000 1059000E 4500
12 105A0000 1185000E 4500
13 11910000 12BC000E 4500
14 13020000 142D000E 4500
2014545

I changed the data set name and the volume serials. The extent information is unchanged as is the total allocation.

In theory, if you play with the numbers you can do a little better, though you'll wind up with an odd number, like 291 cylinders. My conclusion is just leave it at 300 cylinders, at least if you're dealing with 3390-9 type volumes. Now if you're dealing with smaller volumes, like 3390-3 or 3390-2, it might be worth diddling with the secondary allocation.

IBM Mainframe Forum

Size of extent

Size of extent

Re: Size of extent

Re: Size of extent

Re: Size of extent

Re: Size of extent

Re: Size of extent