ALOCBLOK ALOCBLOK provides information on the temporary disk space availatle to a virtual machine.
The RDEVALLN field in the RDEVBLOK points to the ALOCELCK. i
o ALOCPNT ALOCUSED ALOC8AI 1 ------------------------------------------------------1
8 ALOCNTMP t//////////////////////////////////////////I
------------------------------------------------------1 10 ALOC!UP 1 Hexadecimal Field
Displacement Name Field Description, Contents, 8eaning o
4
6
8
A 10 4
6 ALOCPNT DS ALOCUSED DS ALOCMAI DS ALOCNTMP DS DS ALOCMAP DS 1F 18 18 18 38 OF Bits defined in ALOCMIP (j-;;-cylinder is available 1 = Cylinder has been assigned
Pointer to next lLOCELOK on chain Number of nontemporary cylinders Maximum number of cylinders available Number of nontemporary cylinders
Reserved for IBM use Cylinder allocation bit mat Note: The size of ALOCftAP is and depends uton the number of
cylInders on the device. Generally. the size of the lLOCELCK is determined
by the following formula: (ALOCIUI+63) No. of Cylinder ALOCSIZE(doublevords) = ------------+ 2 = -------------------+ header
64 Bits per doublevord lLOCM11 for 2305-1 = 48 cylinders
for 2305-2 96 cylinders
for 2314 = 203 cylinders
for 3330-1 = 404 cylinders
for 3330-2 = 404 cylinders
for 3330-11 = 808 cylinders
for 3333-1 = 404 cylinders
for 3333-11 = 808 cylinders
for 3340-35 = 349 cylinders
for 3340-70 = 698 cylinders
for 3350 = 555 cylinders
for all others 1 cylinder
Note that any bits in the map that represent cylinders nct present on
the device are set to 1. ORG ALOCCYL1 DS ALOCCYL2 DS ALOCUSED 1H
1H !D X·OO· = Cylinder is available
First cylinder of T-disk area
Last cylinder of T-disk area
4 IBM VM/370 Data Areas and Control Block Logic

lLCCBLOK I'AA' = Cylinder has been allocated
Note: The size of the T-disk ALCCMAP is variable aDd depends upon the nu.ber of cylinders in the range ALOCCYL1 to ALOCCYL2. Generally, the size
of a given block is determined by the following formula: {
(ALOCCYL2-ALOCCYL1+1+7} ALOCSIZE(doublevords) = +2 = + header
Bytes per doublevord
Note that bytes for cylinders that are not available are marked assigned. Section 1. CF Data Areas and Centrol Elocks 5