zfsadm grow


zfsadm grow makes the physical size of an aggregate larger.


zfsadm grow -aggregate name -size kbytes [-level] [-help] [-trace file_name]


-aggregate name
Specifies the name of the aggregate to be grown. The aggregate name is not case-sensitive. It is always translated to uppercase.
Prints the online help for this command. All other valid options that are specified with this option are ignored.
Prints the level of the zfsadm command. This option is useful when you are diagnosing a problem. Except for -help, all other valid options specified with -level are ignored.
-size kbytes
Specifies the new total size in kilobytes of the aggregate after the grow operation. The size is rounded up to a control area (CA). A control area is normally a cylinder or less and is based on the primary and secondary allocation units. If zero is specified, the secondary allocation size is used. The value that is specified cannot exceed the size of a single volume.
-trace file_name
Specifies the name of the file that will have the trace records written into it. The trace file can be a z/OS UNIX file, an existing MVS sequential data set, or a member of either an existing partitioned data set (PDS) or partitioned data set extended (PDSE). Use this option only at the direction of IBM Support.

For information about preallocation instructions for debugging, see Step 5 (Optional) Preallocate data sets for debugging in zFS installation and configuration steps.

Because MVS data set names must be fully qualified, z/OS UNIX has special rules for specifying MVS data set names in the shell environment. For more information, see Specifying MVS data set names in the shell environment in z/OS UNIX System Services Command Reference.

Usage notes

  1. The zfsadm grow command attempts to extend the size of an aggregate when the size specified is greater than the current size of the aggregate or when the size is specified as zero. If the extend fails (for example, if there is no space on the volume, or if size zero is specified and there is no secondary allocation specified for the VSAM linear data set), the grow operation fails. If the size specified is less than or equal to the current size of the aggregate, no extend is attempted and the command successfully returns. An aggregate cannot be made smaller than its current size. In any case, if the aggregate's high used value is less than the aggregate's high allocated value, the aggregate will be formatted up to the high allocated value (making the high used value equal to the high allocated value). The current (formatted) size of an aggregate can be determined by using the zfsadm aggrinfo command. The high used value (HI-U-RBA) and the high allocated value (HI-A-RBA) can be determined by using the IDCAMS LISTCAT ALL command.
  2. The size of the file system free space is increased by the amount of additional space available.

Privilege required

The issuer must be logged in as a root user (UID=0) or have READ authority to the SUPERUSER.FILESYS.PFSCTL resource in the z/OS® UNIXPRIV class.


The following command displays the online help entry for the zfsadm grow command:

zfsadm grow -help

Usage: zfsadm grow -aggregate <name> -size <size in K bytes> [-level] [-help]

Related information

  • zfsadm aggrinfo
  • zfsadm fsinfo