Managing Your File Space

File spaces are not infinite, but contain a certain amount of space that your system administrator allocates to you. When your user ID was added to a file pool, the system administrator also allotted you a certain amount of space. If necessary, you can ask your system administrator to change your space allocation.

At any time, you can determine the amount of space you have used and how much more is available. To determine what proportion of your file space you have used, you would enter the QUERY LIMITS command (substituting the name of your file pool for the filepoolid):
query limits * filepoolid:
If you defined a default file pool, then just enter:
query limits
Your output will look like this:
Userid    Storage Group   4K Block Limit   4K Blocks Committed  Threshold
yourid            3            1000             820-82%             90%

The first column shows your user ID (yourid in this example). The column labeled Storage Group shows the storage group within your file pool where your system administrator has assigned you.

The third and fourth columns contain information regarding the size of the file space. The third column shows that you have been allocated 1000 4K block units. The 4K Blocks Committed column shows that of the 1000 4K blocks you were allocated, you have used 820, which is 82% of the total.

The column labeled Threshold shows when you will receive a warning from the system informing you that your file space is almost full. The default threshold is 90%. When your file space is 90% full, you will receive a warning. If you wish to change the threshold, you can do so by issuing the SET THRESHOLD command. For more information on the SET THRESHOLD command, see z/VM: CMS Commands and Utilities Reference.

Note: This warning message will be seen only once for a file pool in between console reads. An example of a console read occurring is when you press the Enter key.

If, while using CMS, your file space becomes 100% full, you will receive an error message. At this point, you can use the FILELIST command to list the files in your file space, then use the DISCARD command to erase any unwanted files.

You can find out how much space you will free by erasing an SFS file by using the QUERY BLOCKS command. For example, if you enter:
query blocks myfile script a
for file myfile script in the VMSYSU:SMITH.ALL.FILES directory, accessed as A, you will see:
Directory = VMSYSU:SMITH.ALL.FILES
Filename Filetype Fm Type Datablocks Systemblocks
MYFILE   SCRIPT   A  BASE 10         2
The file is taking up 12 blocks of file space, so if you erase this file, you will free 12 blocks of space.

You may have files in your file space whose data has been moved into storage controlled by DFSMS/VM. They are referred to as being in migrated status (this will be discussed in more detail in DFSMS/VM and SFS File Management). You should be aware that although these files take up logical storage in your file space, they no longer occupy real storage as long as they are in migrated status. If they are recalled from migrated status, they will once again require physical space in your storage group. This recall happens automatically when you reference the file data if the SET RECALL command is set to ON. For more information about SET RECALL, see z/VM: CMS Commands and Utilities Reference.

If you cannot erase any of the files in your file space, there are several alternative recovery paths you can take:

  1. If you are able to store any of your files on minidisks, you may be able to use the COPYFILE command to move files from your file space to a read/write minidisk. After copying the files, erase the original copy in your file space.
  2. If you do not have any read/write minidisks in your virtual machine, you may be able to transfer some of your files to another user, using either the SENDFILE, PUNCH or DISK commands. When the files have been read into the other user's file space, you can erase them from your file space.
  3. You can overlay the contents of a file with a packed version of the file, using the COPYFILE command with PACK option. To browse or modify the contents of a packed file, you must recopy the file to itself using the COPYFILE command with UNPACK option.
  4. You may contact your file system administrator to request that more storage be added to your file space.