/ACCESSED[=n]
Requires OPER (operator) privilege.
Specifies the number of directories to be maintained in system space 
for ready access. You can specify a value n in the range of 0 
to 255. If you specify the qualifier /ACCESSED and omit the number of 
directories, a default value of 3 is used. If you specify a value 
greater than the current value, the new value is effective immediately; 
otherwise, the new value is not effective until the next time the 
volume is mounted.
/CACHE=(option[,...])
Enables or disables XFC caching for the volume. If CLEAR_DATA option is 
specified, then contents of the volume already in cache are cleared. 
(If you do not specify the /CACHE qualifier, XFC caching attributes of 
the volume as well as the contents of the volume already in cache are 
not affected.) Keywords are as follows:
  
    | Keyword  | 
    Description  | 
  
  
    | 
      DATA
     | 
    
      Enables XFC caching for the volume.
     | 
  
  
    | 
      [NO]DATA
     | 
    
      Disables XFC caching for the volume.
     | 
  
  
    | 
      CLEAR_DATA
     | 
    
      Clears contents of the volume present in the XFC cache (if any).
     | 
  
/DATA_CHECK[=(option[,...])]
Defines a default for data check operations following all read and 
write operations to the specified volume. (If you do not specify the 
/DATA_CHECK qualifier, no checks are made.) Keywords are as follows:
  
    | 
      [NO]READ
     | 
    
      Performs checks following all read operations.
     | 
  
  
    | 
      [NO]WRITE
     | 
    
      Performs checks following all write operations (default).
     | 
  
/ERASE_ON_DELETE
/NOERASE_ON_DELETE (default)
Determines whether the space occupied by a file is overwritten with a 
system-specified pattern when a file on the volume is deleted.
/EXTENSION[=n]
Specifies the number of blocks to be used as a default extension size 
for all files on the volume. You can specify a value n in the 
range of 0 to 65,535. If you specify the /EXTENSION qualifier without 
specifying a value, a default value of 0 (the OpenVMS RMS default) is 
used.
For example, during an update operation, the extension default is used 
when a file increases to a size greater than its initial default 
allocation.
/FILE_PROTECTION=(ownership[:access][,...])
Sets the default protection to be applied to all files on the specified 
disk volume. Specify the ownership parameter as system (S), 
owner (O), group (G), or world (W) and the access parameter as 
read (R), write (W), execute (E), or delete (D). A null access 
specification means no access.
  Note 
This attribute is not used while the volume is in use on an OpenVMS 
system, but the attribute is provided to control the process use of the 
volume on RSX-11M systems. The OpenVMS system always uses the default 
file protection; the protection can be changed with the DCL command SET 
PROTECTION/DEFAULT. 
     | 
  
/HIGHWATER_MARKING
/NOHIGHWATER_MARKING
Determines whether the file highwater mark (FHM) volume attribute is 
set. The FHM attribute guarantees that a user cannot read data that was 
not written by the user. Applies to Files-11 On-Disk Structure Level 2 
(ODS-2) and 5 (ODS-5) volumes only.
/LABEL=volume-label
Specifies a 1- to 12-character ANSI name to be encoded on the volume. 
The specified label remains in effect until it is changed explicitly; 
dismounting the volume does not affect the label. HP strongly 
recommends that a volume label should consist of only alphanumeric 
characters, dollar signs ($), underscores (_), and hyphens (-).
  Note 
Changing the volume label does not change other structures that used 
the original volume label. For example, the DISK$label logical 
volume name is not changed nor is the device-lock name that is kept 
internally by OpenVMS. As a result, if you attempt to access another 
disk that has the same volume label as the original volume of this 
device, you may get error messages such as the following: 
"%MOUNT-F-VOLALRMNT, another volume of same label already mounted".
HP recommends that, if you change a disk volume label, you also 
dismount and remount the disk on all nodes in the cluster so that the 
names and locks are consistent.  
     | 
  
If you change the volume label on a nonsystem disk and the PRODUCT 
INSTALL command has been used to install software products on that 
disk, you must update the software product database to reflect this 
change. To accomplish this, first dismount and remount the disk. Then 
use the PRODUCT REGISTER VOLUME command to replace all occurrences of 
the old DISK$label with the new logical volume name that was 
created by the MOUNT command.
  Note 
         You do not need to take this action when you change the label of the 
         system disk. The POLYCENTER Software Installation Utility continues to 
         use the old logical volume name until the system is rebooted. After 
         reboot (when the system disk is remounted), the utility automatically 
         identifies the system disk using its new logical volume name. 
     | 
  
/LIMIT[=n]
Specifies that the volume is to be enabled for volume expansion. 
n specifies the upper limit of the expansion (in blocks). If 
no value is specified, the maximum expansion potential is set up.
The maximum expansion size depends on the cluster size defined for the 
volume using the INITIALIZE/CLUSTER_SIZE command. If the cluster size 
is 8 or more, the current maximum expansion supported on OpenVMS (1TB) 
is set up. If the cluster size is less than 8, the expansion limit is 
set to 65535*4096*Cluster-size because the maximum size of the bitmap 
is 65535 blocks. For more information about volume expansion, see the 
HP Volume Shadowing for OpenVMS manual.
This command must be executed while the disk is mounted privately.
If you add additional physical storage in the future, you can use the 
/SIZE qualifier to increase the volume size.
/LOG
/NOLOG (default)
Determines whether the volume specification of each volume is displayed 
after the modification.
/MOUNT_VERIFICATION
/NOMOUNT_VERIFICATION
Determines whether mount verification is enabled. Mount verification 
prevents interruption to user input/output operations and notifies the 
operator of problems with the disk.
/OWNER_UIC[=uic]
Sets the owner user identification code (UIC) of the volume to the 
specified UIC. The default UIC is that of the current process. Brackets 
([]) are required around the UIC. Specify the UIC by using standard UIC 
format as described in the HP OpenVMS Guide to System Security.
/PROTECTION=(ownership[:access][,...])
Specifies the protection to be applied to the volume. The following 
rules apply:
  - Specify the ownership parameter as system (S), owner (O), 
  group (G), or world (W).
  
 - Specify the access parameter as read (R), write (W), 
  create (C), or delete (D).
 
The default protection is all types of access by all categories of user.
/REBUILD[=FORCE]
Recovers caching limits for a volume that was dismounted improperly. If 
a disk volume was dismounted improperly (such as during a system 
failure), and was then remounted with the MOUNT/NOREBUILD command, you 
can use SET VOLUME/REBUILD to recover the caching that was in effect at 
the time of the dismount. The FORCE option forces the disk to be 
rebuilt unconditionally, thus updating the free block count in the disk 
volume's lock value block.
/RETENTION=(min[,max])
Specifies the minimum and maximum retention times to be used by the 
file system to determine the expiration date for files on the volume. 
When a file is created, its expiration date is set to the current time 
plus the maximum time. Each time the file is accessed, the current time 
is added to the minimum time. If the sum is greater than the expiration 
date, a new expiration date is computed.
If you omit the maximum value, a default value that is the smaller of 
(2 x min) or (min + 7) days is used. For example, /RETENTION=3- is the 
same as /RETENTION=(3-,6-), while /RETENTION=10- is the same as 
/RETENTION=(10-,17-).
The command SET VOLUME/RETENTION=0 disables retention times on the 
volume.
/SIZE[=nnn]
Specifies the amount of disk space (in blocks) that is usable for the 
file system. This value must be greater than the current logical volume 
size and less than or equal to the physical size of the disk or the 
expansion limit (specified by /LIMIT), whichever is smaller.
If the value is omitted, the usable space is increased to the physical 
size of the disk or the expansion limit, whichever is smaller.
/STRUCTURE_LEVEL=n
Sets the structure level of the volume. Use the value 5 to set the 
volume to ODS-5.
When the /STRUCTURE_LEVEL qualifier is used with other qualifiers, the 
volume structure level is set prior to the other qualifiers being 
performed.
You cannot use the SET VOLUME command to change a volume from ODS-5 to 
ODS-2. To reset a volume to ODS-2, see the instructions in the 
HP OpenVMS System Manager's Manual, Volume 1:  Essentials.
/SUBSYSTEM 
/NOSUBSYSTEM
Enables the processing of subsystem ACEs. Requires the SECURITY 
privilege. By default, the disk from which you boot has protected 
subsystems enabled but other disks do not. For further details on 
subsystems, see the HP OpenVMS Guide to System Security.
/UNLOAD (default)
/NOUNLOAD
Specifies whether the volume is unloaded (spun down) when the DCL 
command DISMOUNT is entered.
/USER_NAME[=user-name]
Specifies a user name of up to 12 alphanumeric characters to be 
recorded on the volume. The default name is the current process user 
name.
/VOLUME_CHARACTERISTICS=([[NO]HARDLINKS,] 
[[NO]ACCESS_DATES[=delta-time]])
Enables or disables hardlinks and automatic updates of access dates on 
ODS-5 volumes.
To limit the performance impact if a file is accessed frequently, you 
can suppress update of the access time if the change is small. A delta 
time is used to determine when a new access time is significant. The 
default value for delta-time is 1 second, chosen to comply 
with the "seconds since EPOCH" time interface required by POSIX
st_atime
. A site can choose a larger delta time to reduce overhead if 1-second 
granularity is not required.
To disable access date support on a volume, use the SET 
VOLUME/VOLUME_CHARACTERISTICS=NOACCESS_DATES command. This command 
affects only the node on which the command is issued. Other nodes are 
not affected by the change until the next time the volume is mounted.
For additional information about ODS-5 volumes, see the Guide to OpenVMS File Applications 
and to the sections about File Service Extensions in the OpenVMS Alpha Version   7.3--1 New Features and Documentation Overview. 
This archived manual is on the OpenVMS documentation Website:
 
http://www.hp.com/go/openvms/doc
Click on "Archived documents" in the left sidebar to link to 
this manual.
/WINDOWS[=n]
Specifies the number of mapping pointers to be allocated for file 
windows.
The value of n can be from 7 to 80; the default value is 7.
/WRITETHROUGH
/NOWRITETHROUGH
This qualifier only affects applications such as PATHWORKS that can 
request deferred writes to file headers. You use it to control whether 
these applications can use the deferred write feature.
Use /NOWRITETHROUGH to allow these applications to use the deferred 
write feature. When one of these applications explicitly requests a 
deferred write when updating a file header, control returns to the 
application when the I/O request has been queued; the application does 
not have to wait until the data is on disk.
Note that although the SHOW DEVICES/FULL command shows the volume 
status as write-back caching enabled, the extended file cache 
(XFC) will still be in write-through mode.
Use /WRITETHROUGH to disable the deferred write feature, so that no 
applications can use it. The SHOW DEVICES/FULL command shows the volume 
status as write-through caching enabled.
The deferred write feature is not available on Files-11 ODS-1 volumes.