syncvg Command

Purpose

Synchronizes logical volume copies that are not current.

Syntax

syncvg [ -f ] [ -i ] [ -H ] [ -P NumParallelLps ] { -l | -p | -v } Name ...{ [ -a { all | pid1,pid2,… } ] [ -r { all | pid1,pid2,… } ] [ -t { all | pid1,pid2,… } ] [ -n vgName ] [ -T SyncRate [ -d { all | pid1,pid2,… } ] ] [ -q ] [ -Q ] }

Description

The syncvg command synchronizes the physical partitions, which are copies of the original physical partition, that are not current. The syncvg command can be used with logical volumes, physical volumes, or volume groups, with the Name parameter representing the logical volume name, physical volume name, or volume group name. The synchronization process can be time consuming, depending on the hardware characteristics and the amount of data.

When the -f flag is used, a good physical copy is chosen and propagated to all other copies of the logical partition, whether or not they are stale. Using this flag is necessary in cases where the logical volume does not have the mirror write consistency recovery.

Unless disabled, the copies within a volume group are synchronized automatically when the volume group is activated by the varyonvg command.

Note: For the syncvg command to be successful, at least one good copy of the logical volume should be accessible, and the physical volumes that contains this copy should be in ACTIVE state. If the -f option is used, the above condition applies to all mirror copies.

If the -P option is not specified, syncvg will check for the NUM_PARALLEL_LPS environment variable. The value of NUM_PARALLEL_LPS will be used to set the number of logical partitions to be synchronized in parallel.

Flags

Item	Description
-a { all \| pid1,pid2,… }	Pauses one or more sync operations. The following parameters can be passed to this option: all Pause all sync operations. pid1,pid2,... A comma separated list of process ID (PID) to pause.
-f	Specifies a good physical copy is chosen and propagated to all other copies of the logical partition, whether or not they are stale.
-H	Postpones writes for this volume group on other active concurrent cluster nodes until this sync operation is complete. When using the -H flag, the -P flag does not require that all the nodes on the cluster support the -P flag. This flag is ignored if the volume group is not varied on in concurrent mode.
-i	Reads the names from standard input.
-l	Specifies that the Name parameter represents a logical volume device name.
-n vgName	Manages sync operations for a specific volume group. This option is only valid with the -a, -r, -t , -q and -Q options. vgName Volume group name.
-p	Specifies that the Name parameter represents a physical volume device name.
-P NumParallelLps	Numbers of logical partitions to be synchronized in parallel. The valid range for NumParallelLps is 1 to 32. NumParallelLps must be tailored to the machine, disks in the volume group, system resources, and volume group mode. When a volume group is varied on in concurrent mode, all other cluster nodes that have this volume group varied must be at least AIX® 4.3.0, otherwise syncvg will ignore this option and continue. Note: See Description above for more information.
[-q]	Queries sync operations. A verbose list of sync operation Process Identifiers (PIDs) is returned. This flag also outputs the sync rate for each sync operation. If the SyncRate option is not specified using the -T flag, this flag displays the current sync rate of the sync operation.
[-Q]	Queries sync operations. A comma separated list of sync operation PIDs is returned. This flag also returns the sync rate for each sync operation. If the SyncRate option is not specified using the -T flag, this flag displays the current sync rate of the sync operation.
{-r all \| pid1,pid2,… }	Resumes one or more sync. The following parameters can be passed to this option: all Resumes all sync operations. pid1,pid2,... A comma separated list of PIDs to resume.
{-t all \| pid1,pid2,… }	Terminates one or more sync. The following parameters can be passed to this option: all Terminates all sync operations. pid1,pid2,... A comma separated list of PIDs to terminate.
[ -T SyncRate [ -d { all \| pid1,pid2,… } ] ]	Throttles the sync rate of the current sync operation or throttles one or more sync operations that are in progress. The following parameters can be passed to this option: SyncRate Specifies the sync rate, in MB/sec, to throttle. The syncvg command synchronizes one Logical Track Group (LTG) at a time. This parameter must be specified in multiples of the LTG size of the volume group. If the SyncRate parameter is not specified in the multiples of the LTG size, the syncvg command rounds up to the nearest LTG size of the volume group. If you do not specify the -d flag, the syncvg command throttles the sync rate of the current sync operation. -d all Throttles the sync rate for all the sync operations that are in progress. -d pid1,pid2,… A comma-separated list of PIDs that throttle the sync rate.
-v	Specifies that the Name parameter represents a volume group device name.

Security

Attention RBAC users and Trusted AIX users: This command can perform privileged operations. Only privileged users can run privileged operations. For more information about authorizations and privileges, see Privileged Command Database in Security. For a list of privileges and the authorizations associated with this command, see the lssecattr command or the getcmdattr subcommand.

Examples

To synchronize the copies on physical volumes hdisk4 and hdisk5, enter:
```
syncvg -p hdisk4 hdisk5
```
To synchronize the copies on volume groups vg04 and vg05, enter:
```
syncvg -v vg04 vg05
```

To display the synchronization status, enter:

syncvg -q
An output that is similar to the following example is displayed.
VG Name    Status        Sync Rate     PID            Command
tvg2       SYNCING       128M          8323316         /bin/ksh /usr/sbin/syncvg -l tvg2lv1
tvg2       SYNCING       1M            7536758         /bin/ksh /usr/sbin/syncvg -l tvg2lv3
tvg2       SYNCING       256M          6815782         /bin/ksh /usr/sbin/syncvg -l tvg2lv2
tvg1       SYNCING       2G            7995416         /bin/ksh /usr/sbin/syncvg -l tvg1lv2
tvg1       SYNCING       5M            2949162         /bin/ksh /usr/sbin/syncvg -l tvg1lv3
tvg1       SYNCING       1G            7274582         /bin/ksh /usr/sbin/syncvg -l tvg1lv1

To pause the syncvg command and then display the synchronization status, enter:

syncvg -a all
syncvg -q
An output that is similar to the following example is displayed.
VG Name    Status        Sync Rate     PID          Command
tvg2       PAUSE         128M          8323316       /bin/ksh /usr/sbin/syncvg -l tvg2lv1
tvg2       PAUSE         1M            7536758       /bin/ksh /usr/sbin/syncvg -l tvg2lv3
tvg2       PAUSE         256M          6815782       /bin/ksh /usr/sbin/syncvg -l tvg2lv2
tvg1       PAUSE         2G            7995416       /bin/ksh /usr/sbin/syncvg -l tvg1lv2
tvg1       PAUSE         5M            2949162       /bin/ksh /usr/sbin/syncvg -l tvg1lv3
vg1        PAUSE         1G            7274582       /bin/ksh /usr/sbin/syncvg -l tvg1lv1

To synchronize the current syncvg operation with a sync rate of 512 MB/sec on a volume group named vg00, enter:
```
syncvg -T 512 -v vg00
```

Files

Item	Description
/usr/sbin/syncvg	Contains the syncvg command.
/tmp	Directory where the temporary files are stored and while the command is running.