MOUNT

Purpose

MOUNT is a TSO/E command that mounts a file system into thez/OS® UNIX hierarchy. This section only documents MOUNT options that are unique to zFS. It can also be invoked from the z/OS UNIX shell (/usr/sbin/mount). For more information about MOUNT command description, see z/OS UNIX System Services Command Reference.

Beginning with z/OS V2R3, a newly created VSAM linear data set will be formatted during its first mount if the following conditions are true:
  • VSAM linear data set is defined with the ZFS keyword (instead of LINEAR) or defined by using the zfsadm define command from a z/OS V2R3 or later system.
  • The size of the aggregate is 0.
  • The user who issues the mount also has the authorization that is needed for the format.
  • The aggregate can be created with the default format options.
  • The root directory of the aggregate can be created by using permissions from the IOEFSPRM configuration option format_perms setting. See IOEFSPRM for a description of the format_perms option.
Notes:
  1. Beginning with z/OS V2R1, zFS clones are no longer supported. An attempt to mount an aggregate that contains a .bak (clone) file system is denied.
  2. Beginning with z/OS V2R1, multi-file system aggregates are no longer supported. An attempt to mount a zFS file system that is contained in a zFS multi-file system aggregate is denied.

Format

MOUNT TYPE(file_system_type) [PARM(parameter_string)]

Options

TYPE (file_system_type)
Specifies the file system type. Specify ZFS or HFS and the correct file system type is determined for the file system that is located by the data set name. If the TYPE specified (HFS) does not match the real file system type (ZFS), any associated ZFS parameters are ignored. For more information, see Mounting considerations in z/OS UNIX System Services Planning.
PARM(parameter_string)
Specifies a parameter string to be passed to zFS. Parameters are case-sensitive and separated by a comma. Enclose the parameter string within quotation marks. If a parameter is specified multiple times, the last parameter is used.

If the value specified on the TYPE parameter (HFS) does not match the real file system type (ZFS), any associated ZFS parameters are ignored.

AGGRFULL(threshold,increment)
Specifies the threshold and increment for reporting aggregate utilization messages to the operator. The default is the aggrfull specification in the IOEFSPRM file. For version 1.5 aggregates, if aggrfull is not specified in the IOEFSPM file, the default is taken from the fsfull specification.
AGGRFULL and FSFULL provide the same function. You can use either one (or both) to monitor the space utilization for an aggregate. However, AGGRFULL tends to give a more accurate view of free space and is the suggested choice.
  • For version 1.4 aggregates, if both AGGRFULL and FSFULL are specified, both will be used.
  • For version 1.5 aggregates, if AGGRFULL is specified, FSFULL is ignored.
If AGGRFULL is not specified, the FSFULL specification isf used as if it were the AGGRFULL specification.
AGGRGROW | NOAGGRGROW
Specifies whether the aggregate is eligible to be dynamically grown. The growth is based on the secondary allocation of the aggregate and will occur when the aggregate becomes full. The default is the aggrgrow specification in the IOEFSPRM file.
CONVERTTOV5 | NOCONVERTTOV5
Specifies whether a zFS read/write file system is assigned the converttov5 attribute. If it is assigned the converttov5 attribute and the aggregate is a version 1.5 aggregate, zFS automatically converts directories from v4 to extended (v5) as they are accessed. If the converttov5 attribute is assigned at primary mount time, a version 1.4 aggregate is changed to a version 1.5 aggregate.

If automatic directory conversion for a directory fails, the conversion is not attempted again until the file system is unmounted and mounted again.

The converttov5 attribute can also be assigned if the MOUNT option is not specified but the converttov5 specification in the IOEFSPRM file is on when the file system is mounted or remounted.

The default is NOCONVERTTOV5. However, the converttov5 attribute can also be assigned if the converttov5 specification in the IOEFSPRM file is on when the file system is mounted or remounted.

FSFULL(threshold,increment)
Specifies the threshold and increment for reporting file system utilization messages to the operator. The default is the fsfull specification in the IOEFSPRM file.

AGGRFULL and FSFULL provide the same function. You can use either one (or both) to monitor space utilization for an aggregate. However, AGGRFULL tends to give a more accurate view of free space and is the suggested choice. For version 1.5 aggregates, if AGGRFULL is specified, this option is ignored. It it is not specified, the FSFULL threshold and increment values are used to report aggregate utilization messages.

RWSHARE | NORWSHARE
Specifies whether a zFS read/write mounted file system will be mounted sysplex-aware or non-sysplex aware. zFS must be running sysplex-aware on a file system basis (IOEFSPRM specifies sysplex=filesys) for this parameter to take effect. The default is the sysplex_filesys_sharemode specified in the IOEFSPRM file, or later by using the zfsadm config command. For information about whether to make a read/write file system sysplex aware, see Using zFS read/write sysplex-aware file systems.

Usage notes

  1. A mount of a compatibility mode aggregate is serialized with other zfsadm commands (because the mount of a compatibility mode aggregate does an implicit attach).
  2. If you attempt to mount a compatibility mode aggregate/file system read-only and it fails because it needs to run recovery (return code EROFS (141) and reason code EFxx6271), you should temporarily mount it read/write so it can complete the recovery process. Then, mount it read-only. Alternatively, you can specify the romount_recovery=on configuration option in IOEFSPRM. This causes the file system to automatically be temporarily mounted read/write to allow log recovery to run and then to be mounted read-only.
  3. If the file system being mounted is eligible for compression and the user cache is not registered with the zEDC Express service, zFS will attempt to register the user cache after the mount completes. zFS constraints might prevent zFS from registering the entire user cache with the zEDC Express service. The zfsadm compress command will cause the ZFS_VERIFY_COMPRESSION_HEALTH check to be run.
  4. If the DASD volume containing the zFS compatibility mode aggregate being mounted is read-only, you can receive message IOEZ00336I. This message indicates that the zFS aggregate indicator cannot be set in the catalog (actually, in the VVDS on the volume). The zFS aggregate is successfully mounted (and attached). DFSMSdss backup (DUMP) will not automatically quiesce and unquiesce the zFS aggregate because it cannot determine that the VSAM linear data set is a zFS aggregate. If the zFS aggregate can be mounted with the DASD volume in read/write, the zFS aggregate indicator will be set.
  5. You can determine whether the zFS aggregate indicator is set by using IDCAMS LISTCAT ALL against the zFS aggregate and looking for the zFS indicator in the output.
  6. Do not use a path entry as the file system name in the MOUNT command (see DEFINE PATH in z/OS DFSMS Access Method Services Commands). The mount succeeds but the system issues messages similar to the following one: 
    IOEZ00412I Catalog search failed for aggregate PLEX.JMS.AGGR006.PATH. Shareoptions are not altered.

IOEZ00336I PLEX.JMS.AGGR006.PATH could not be marked as a zFS aggregate in the catalog, rc=60 rsn=104

Examples

The following TSO/E example mounts a zFS file system and specifies a threshold and increment to display a message when the file system becomes almost full: 
MOUNT FILESYSTEM(’OMVS.PRV.AGGR004.LDS0004’) MOUNTPOINT(’/etc/zfscompat1’) 
      TYPE(ZFS) MODE(RDWR) PARM('AGGRFULL(90,5)')
The same example as a z/OS UNIX command follows: 
/usr/sbin/mount -f OMVS.PRV.AGGR004.LDS0004 -t ZFS -o ’AGGRFULL(90,5)’ /etc/zfscompat1

Related information

Commands:
Files:
  • IOEFSPRM