vxvol(1M)

(SRVM only) Associates the named volume with the specified rvg as the Storage Replicator log volume. The volume must have a usage-type of gen or fsgen, and cannot have a DRL associated with it.

(SRVM only) Associates the named volume with the specified rvg as a data volume. The volume must have a usage-type of gen or fsgen, and cannot have a DRL associated with it.

(SRVM only) Dissociates the named volume from its associated rvg.

Performs an initialization action on a volume. This can be applied to volumes that were created by vxmake and that have not yet been initialized, or volumes that have been set to the uninitialized state with vxmend fix empty. The action to perform is specified by the init_type operand, which is usage-type-dependent. The volume operand determines which usage type to use for performing the operation.

Detaches each volume named by the volume operands. When a volume is detached, normal read and write operations to the volume fail, although most volume ioctl operations can still be used.

When a node in a cluster aborts or crashes, it is not allowed to rejoin the cluster until the active logs of the volumes affected by the crash are recovered. The noderecover operation examines all volumes named by the volume operands and recovers the active log maps corresponding to the crashed nodes, but does not initiate mirror resynchronization. Mirrors are subsequently resynchronized by a vxvol -o force resync volume... command.

This operation is currently applicable only to the volumes with DRL logs and is relevant only in clustered systems.

Not used in this release.

Sets the read policy for a volume based on the policy operand. These are the recognized read policies:

Some usage types support the concept of recovery of data for objects within a volume different from the mirror resynchronization model. The recover operation is used to specify this type of recovery. The exact procedure for this operation is usage type specific.

Examines all volumes named by the volume operands and perform any synchronization operations that are required. The exact procedure for this operation is usage-type specific.

Changes specific volume characteristics. The changes to be made are given by arguments immediately after the set keyword of the form attribute=value. The set of volumes affected by the operation are given after these operands; thus the attribute list ends with an operand that does not contain an equal sign. To allow for volume names that contain an equal sign, an operand of -- can be used to terminate the attribute list. Each usage type represented by the list of volume operands is called once, with the set of all volumes with that usage type.

The set of attribute=value attribute arguments that are recognized depends upon the volume usage type (see the sections on usage types later in this manual page for information on available attributes). However, an attribute argument of the form len=number is expected to be interpreted (if at all) as requesting a change in the length of a volume, regardless of the volume's usage type. The number value is interpreted as a standard length number (see vxintro(1M)).

Enables disabled or detached volumes named by the volume operands. The process of enabling a volume is a highly usage-type-dependent operation and may result in transfers of data between plexes associated with the volume.

If the start operation is applied to an uninitialized volume (for example, a volume just created by vxmake), a default initialization will be used to initialize and enable the volume.

If the volume is not normally started because failures and disk removals have left all associated plexes with invalid data, the -f option can be used to try to start the volume, anyway. This can be used after replacing disks to enable the volume so that its contents can be restored from backup or reinitialized.

Attempts to start all volumes that are disabled. If a -U usetype option is specified, then attempt to start all disabled volumes with the indicated usage type. This operation will not start uninitialized volumes. By default, start all volumes in the rootdg disk group. A different disk group can be specified with the -g option.

Disables the enabled or detached volumes named by the volume operands.

The stop operation provides an interface to the usage type of a volume for shutting down operations on a volume in a clean manner. The specific method for cleanly stopping a volume, and the precise meaning of ``clean'' are both highly usage-type-dependent. By convention, -f can be used to force stopping of a volume that is in use, forcing I/O failures to be returned for any further volume device operations.

Attempts to stop all volumes that are enabled. If a -o usetype option is specified, then attempt to stop all disabled volumes with the indicated usage type. By default, stop all volumes in the rootdg disk group. A different disk group can be specified with the -g option.

Forces an operation in some situations where the operation has questionable semantics. For example, -f may be used to reduce the length of a volume with vxvol set, to stop a volume that is currently open or mounted as a file system, or to attempt to start a volume that has no plexes with valid data.

Specifies the disk group for the operation. The disk group can be specified either by name or by disk group ID. See vxdg(1M) for more information on disk groups.

(SRVM only) Maps the data volume to the rvg on the secondary. This is used in the case that the name of the secondary data volume is not the same as that of the corresponding primary data volume. The argument primary_datavol specifies the name of the data volume on the primary.

Note: The mapping is only necessary and is only maintained on the secondary. The primary does not know or care what names the secondary is using for its data volumes.

The current mapping for a secondary volume is given by the primary_datavol field in the long listing of the secondary volume (vxprint -l). If this field is not listed, then global naming is in effect for that data volume, which means that the secondary is using the same name as the primary. The primary_datavol field can also be set for a secondary data volume with vxedit(1M).

Passes in usage-type-specific options to the operation. By convention, the following usage-type-specific options should be implemented by all usage types:

(SRVM only) Specifies an alternative replicated volume for use as a data or log volume. This option is only used with the assoc and aslog operations.

Waits for the volume daemon if it is not running or available for transactions. If -q is not specified, vxvol aborts if the volume daemon is not available.

Specifies a rendezvous file path name for regular configuration and query requests. /etc/vx/vold_request is the default.

If any tasks are registered to track the progress of the operation, mark them with the tag tasktag. The tag specified by tasktag is a sequence of up to 16 alphanumeric characters.

Associates new tasks with the specified parent task ID.

Forces the operation to be performed by the usage-type utility for this usage type.

Displays a list of utilities that would be called from vxvol, along with the arguments that would be passed. The -V option performs a preview run so the utilities are not actually called, and no changes are made to the volume configuration database.

Forces an operation that is not normally performed as part of the operational model of the Volume Manager and may have adverse effects on data. This is the same as -f.

Prevents the start operation from recovering plexes through the vxplex utility. Instead, all STALE and ACTIVE plexes are simply treated as equivalent to CLEAN plexes, and are thus enabled without being made consistent. This can be used for volumes whose contents are recreated for each use. Note: This option can only be used with the gen usage type.

An example of a possible use for this attribute is a swap area and the /tmp file system. In the case of /tmp, the model assumes that mkfs is used to create an empty file system after the volume has been started.

These are the recognized uses of the vxvol init operation:

The -f option is required to detach an enabled volume. Also, a warning is written to the standard error for volumes that are open or mounted.

Volumes that have possibly differing plex contents are resynchronized to contain consistent data. Any such volumes that are in the NEEDSYNC state will be recovered using a read/write-back recovery mode and then put into the ACTIVE state.

Plexes in the SYNC state may already be under recovery and the volume command will take no action to recover them unless the command was invoked with the -o force option.

The attributes that can be changed are:

Starting an uninitialized gen or fsgen volume enables the volume and its plexes, sets the plexes to the ACTIVE state, and recovers the plexes to ensure that each plex has the same contents. If the volume has only one plex, then the volume is immediately set to the ACTIVE state; otherwise, the volume is set to the SYNC state and a special read/write-back mode is set to recover regions of the volume on every read operation. The volume is then read from beginning to end to make all plexes consistent, then the volume is set to the ACTIVE state.

Starting a volume with no active dirty region logging involves enabling all CLEAN and ACTIVE plexes and putting them in the ACTIVE state. If an I/O failure was logged against the plex, or if a disk replacement caused a plex to become stale, then the plex is considered STALE. If any of the subdisks for the plex reside on a removed or inaccessible disk, then the plex is ignored for the purposes of starting the volume.

If two or more plexes were enabled, and if the volume was active at the time the system went down, then the state for the volume is set to SYNC and a special read/write-back recovery mode is used to recover consistency of the volume, segment-by-segment, on every read. A process is then started (in the background with the -o bg option) to recover consistency for the entire length of the volume.

If any plexes were considered STALE, then those plexes are attached by calling vxplex att. The number of concurrent plex attach operations are limited based on the rules for -o plexfork.

Recovery of plexes with a dirty region log uses the same rules as for volumes without a valid dirty region log, except that recovery of non-stale plexes is done by scanning the contents of the dirty region log and recovering consistency for those regions listed in the log as requiring recovery.

In addition to enabling the volume and managing the recovery of plex consistency, starting a volume clears any transient operations that were being applied to a volume before the system was rebooted. Starting a volume dissociates and removes temporary plexes or subdisks, and dissociates plexes that were being attached if the attach operation did not complete. Snapshot plexes created by vxassist are also removed.

If the volume is unstartable because there are no valid, non-stale plexes and the -f flag is then specified, all STALE plexes that do not contain unusable subdisks (subdisks on failed or removed disks) will be changed to ACTIVE. The volume will then be started and synchronized from those plexes.

Stopping an fsgen or gen volume disables the volume and its associated plexes. In addition, the utility state for each ACTIVE plex is changed as follows:

Normally, the stop operation fails if any extended operations are using the volume or any of its associated plexes. Such operations are detected as a nonempty value for the tutil0 field in a volume or plex record. If the -f option is specified, then the stop operation ignores volume and plex tutil0 fields.

The -f option must also be given to force the stopping of a volume that is open or mounted as a file system. In this case, a warning message is still written to the standard error, but the stop operation is not otherwise affected. Stopping an open or mounted volume is not normally advisable.

Sets the checkpoint size for a volume. A complete resynchronization of a volume via VOL_R5_RESYNC ioctls can take an extended amount of time. It is conceivable in some circumstances that the operation could be stopped before it complete (such as by a system crash). To avoid having to restart the synchronization from the beginning of the volume (after a certain amount of the volume has been synchronized), a transaction is issued to record the offset to which the resynchronization has completed. This size is called the checkpoint length and can be set using the checkpt option. The default checkpoint length is 64 megabytes.

Prevents the start operation from undergoing some recovery operations. RAID-5 logs, if any are valid, will still be replayed; however, no parity resynchronizations or subdisk recoveries will be performed.

Forces an operation that is not normally performed as part of the operational model of the Volume Manager. It may have adverse effects on the data contained by the volume. This is the same as -f.

Allows the delayrecover option to be ignored if the volume must undergo parity resynchronizations or subdisk recoveries before the volume can be enabled.

Allows access to certain volumes earlier in the starting process than is normally allowed by the operating process of RAID-5 volumes. This can have adverse effects on the data, and can also result in the RAID-5 volume becoming unusable after a system crash or a power failure.

The raid5 usage type recognizes the following uses of the init operation:

The raid5 usage type supports the following invocations of the recover operation:

Examines the named volumes to see if they are enabled and if the parity in any part of a volume is stale; this is normally indicated by a volume state of NEEDSYNC. If so, the volume is placed in the SYNC state and VOL_R5_RESYNC ioctls are issued to resynchronize the parity in those regions. Upon completion, the volume is placed in the ACTIVE state.

The attributes that can be set for raid5 volumes are:

Starting an uninitialized volume (one with a state of EMPTY) zeros any RAID-5 log plexes and then resynchronizes the parity of the volume by issuing VOL_R5_RESYNC ioctls. All subdisks are marked as non-stale and read-write. The volume and RAID-5 plex are then enabled and marked as ACTIVE, and all valid RAID-5 log plexes are marked as LOG. If any RAID-5 log plex proves to be invalid (such as having its NODAREC flag set) its state is set to BADLOG.

Starting a volume that has been shut down cleanly or is not marked as dirty enables the RAID-5 plex and RAID-5 log plexes, and sets the volume kernel state to detached to zero the RAID-5 log plexes for the volume, if any. Once this is completed, all valid RAID-5 log plexes are set to LOG and the volume is enabled and put in the ACTIVE state.

Starting a volume that was not shut down cleanly requires that the parity be resynchronized. If the volume has valid RAID-5 log plexes, the volume is first detached and has its state set to REPLAY, and all log plexes and the RAID-5 plex are enabled. If there are any valid RAID-5 log plexes, their contents are read and their data is written to the appropriate regions of the RAID-5 plex. If reading the RAID-5 logs fails, the logs are marked as invalid and the parity is resynchronized as if there were no logs. Once the replay is complete, the RAID-5 logs are enabled and the volume is enabled and its state is set to ACTIVE.

If the volume needs resynchronization and no valid log plexes exist, the parity must be fully resynchronized. The volume is enabled and its state is set to RESYNC, and the RAID-5 plex is enabled. If usable RAID-5 plexes are available, but contain invalid data, they are zeroed. The parity is then resynchronized by issuing VOL_R5_RESYNC ioctls for the entire length of the volume. Once this is completed, the volume's state is set to ACTIVE. Any usable RAID-5 logs are enabled and set to the LOG state.

If a volume requires full resynchronization (that is, has no usable logs) and the RAID-5 plex has stale or unusable subdisks, the volume is unusable and the start operation will fail. This can be overridden by using the -f flag or the -o force option. In this case, any stale subdisks are marked as non-stale and a full resynchronization is performed; however, this may result in some invalid data being introduced into the volume. If multiple subdisks at the same altitude in the RAID-5 plex are unusable (such as because they have their NODEVICE flag set), the volume is unusable and cannot be overridden.

Once any parity resynchronization has been completed, any subdisks still marked as stale are recovered. This is done by marking the subdisk as stale and write-only and issuing VOL_R5_RECOVER ioctls to regenerate the data on the stale subdisks. The subdisk is then marked as non-stale and read-write.

If the -o delayrecover option is specified, the only recoveries that will be performed are log replays. If the volume requires a parity resynchronization, it is enabled and left in the NEEDSYNC operation, and its parity is marked as stale. Any subdisk recoveries that are needed are not performed, and the stale subdisks are marked as stale.

Normally, if a volume has no RAID-5 logs, it will not be enabled with a stale subdisk or an unusable subdisk because were the system to crash or a power failure occurred while the volume was is in use, the parity could become stale and the volume would be unusable. This behavior can be overridden by specifying the -o unsafe option, which will cause the volume to be enabled during the above situations. As the name suggests, this is considered unsafe because doing so could cause data loss.

If only the -o delayrecover option is specified to start a volume with a stale subdisk or an unusable subdisk, the start operation will fail. In this case, the delayrecover option can be ignored by also specifying the -o syncstartok option.

Stopping a raid5 volume disables the volume and its associated plexes. If the volume is in the SYNC state, it is changed to the NEEDSYNC state so that recovery will be performed at the next start. Any invalid or detached RAID-5 logs are set to the BADLOG state so that they will not be used during the next start.

Normally, the stop operation will fail if any extended operations are using the volume or any of its plexes. Such operations are detected as a non-empty value for the tutil0 field in a volume or plex record. If the -f option is specified, then the stop operation ignores volume and plex tutil0 fields.

The utility that performs volume operations for a particular volume usage type.

The device node that can be used for mounting a file system created on the volume named volume in the disk group named group. Volumes in group rootdg are also directly under the /dev/vx/dsk directory.

The device node that can be used for issuing raw I/O requests and also for issuing ioctl requests to the volume named volume in disk group named group. Volumes in group rootdg are also directly under the /dev/vx/rdsk directory.