# Dataset Allocate dialog box

You use this dialog box to issue an IDCAMS ALLOCATE request to create a data set. You can optionally model it based on the selected data set. To learn about the standard capabilities of a dialog box, see Standard tabs in the dialog boxes of the Storage Toolkit. The topic includes a link to the Reference guides for commands that are used in the Storage Toolkit.

Table 1. IDCAMS ALLOCATE options that are available in the Allocate dialog box of the Storage Toolkit
Option | Description
--- | ---
Fully Qualified Dataset name | Type the fully-qualified name of the data set that you want to allocate.
Model name | Type the name of a model data set that you want to use.
Use model to allocate new dataset | Select this option when you want to use the value of Model name in the allocation of the new data set.
Disposition | You have the option to select a disposition value in this drop-down menu.
Record format | You have the option to select a value for the format of the record in this drop-down menu. Options include fixed-format records, variable-format records, and undefined-format records.
Dataset organization | You have the option to select the data-set organization type in this drop-down menu. Options include DA (direct access); DAU (direct access unmovable); PO (partitioned organization); POU (partitioned organization unmovable); PS (physical sequential); and PSU (physical sequential unmovable).
Dataset type | You have the option to select a data-set type in this drop-down menu. Options include partitioned data set (PDS) and the Hierarchical File System (HFS) for z/OS® UNIX®.
Data class | Type the name of the data class for either SMS or non-SMS-managed data sets.
Record length | Specify the length, in bytes, of the largest logical record in the data set.
Management class | Type the name of the management class for a new data set. When possible, do not specify this value. Allow the value to default through the ACS routines.
Block size | Specify the block size of the data control block (DCB) for the data set.
Storage class | For SMS-managed data sets you can type the storage class name. When possible, allow this value to default through the ACS routines established by the system administrator.
Volser(s) | Choose one of the following values in the list: The serial number of an eligible direct access volume on which a new data set is to be located. OR The serial number of a direct access volume on which an old data set is located. If you use VOLUME for an old data set, the data set must be on the specified volume for allocation to take place. If you do not include VOLUME, the system allocates new data sets to any eligible direct access volume.
Unit | Enter the name of the unit type to which a file or data set is to be allocated. You can list an installation-defined group name, a generic device type, or a specific device address.
Directory blocks | Specify the number of 256-byte records for the directory of a new partitioned data set. Use this parameter to allocate a new partitioned data set.
Space Units | Specify the units and amount of space to allocate to a new data set. Options include the following combinations units and values: BLOCK: An integer value to be multiplied by the Primary value that you specify in the Space area of this dialog box. AVBLOCK: An integer value to be multiplied by the Primary value that you specify in the Space area of this dialog box. CYLINDERS: The Primary value that you specify in the Space area of this dialog box is given in cylinders. (No Value is required for this option.) TRACKS: The Primary value that you specify in the Space area of this dialog box is given in tracks. (No Value is required for this option.)
Release space | Select this option when you want to delete unused space when the data set is closed.
Space | Allocates the amount of space for a new data set. The Primary value specifies the initial number of units of space that is allocated for a data set. For a partitioned data set, a directory quantity is not necessary. The Secondary value specifies the number of units of space to be added to the data set each time the previously allocated space has been filled. You must provide the primary quantity along with the secondary value.