fsmigadm - file system online migration administration utility

VRTSvxfs

fsmigadm analyze [ -l logfile ] target_device mount_point

fsmigadm start [ -o mount_options ] target_device mount_point

fsmigadm status [ mount_point ]

fsmigadm pause [ mount_point ]

fsmigadm resume [ mount_point ]

fsmigadm throttle throttle_speed mount_point

fsmigadm commit mount_point

fsmigadm abort mount_point

fsmigadm list

The fsmigadm utility performs online migrations of a local mount native file system, such as jfs, jfs2, and nfs, to the VxFS file system. Migration is defined as the movement of a complete file system to a new namespace. During migration, a background copy process copies the files from the source file system to the target file system. While the migration is in progress, any operations done by the application are reflected on both the target file system and the source file system.

If the background copy operation is unable to copy any file due to errors, then the list of such files is kept in a file on the VxFS file system. The fsmigadm command displays the name of this file after the migration completes, and the VxFS file system is mounted again. A detailed log file is also maintained in the /var/log directory. This log file contains the details of operations such as pause, resume, and throttle that the user performed, and errors, if any, seen by the background copy process.

The fsmigadm command generates the names of both these files uniquely based on the mount point and process ID (PID).

See the Veritas Storage Foundation Advanced Features Administrator’s Guide for more information on how to use the mostly online migration utility.

This command is not supported for cluster mounted file systems.

Only a superuser can invoke the fsmigadm utility.

Prior to performing migration start, commit, and abort operations, take the application offline.

abort	Aborts the migration. If the background copy operation is completed, abort fails. As a part of the abort operation, fsmigadm unmounts the target file system and the source file system, and then mounts the source file system.
analyze	Analyzes the source file system that is to be converted to VxFS and generates an analysis report. The analysis checks for problems that can prevent the migration from completing successfully. The analysis performs the following checks: o Compares the source file system size and the target volume size. The target volume size should be greater than the source file system size. o Checks for ACLs on source file system. The migration does not preserve ACLs. o Checks for maximum file size compatibility of the source file system versus the target file system. o Issues warnings for source file system features that will not be preserved during migration.
commit	Commits the migration. Bring the application offline before commiting the migration. If the application is online or the migration is not complete, the commit fails.
	As a part of commit operation, the fsmigadm command unmounts both the source file system and the target file system, and then mounts the target file system.
	For mounting the target file system with different mount options, you must remount the file system after committing the migration.
list	Lists all ongoing migrations. The fsmigadm utility displays the following details: o Source device o Target device o Migration status o Mount point
pause	If the mount point is specified, fsmigadm pauses the background copy operation for the specified migration file system. Otherise, fsmigadm pauses the background copy operation for all of the migration file systems on the system. The application remains online even if the background copy operation is paused.
resume	Resumes the background copy operation if the operation was paused or the background copy operation was killed before the migration completed. Otherwise, the resume operation has no effect.
	If the mount point is specified, then the fsmigadm command resumes the background copy operation only for that file system. Otherwise, the fsmigadm command resumes the operation for all file systems under online migration.
start	Starts the migration. The source file system should be mounted before this operation. The application should be offline during this operation. As a part of this operation, fsmigadm makes some preliminary checks, such as checking for target volume size. If these checks fail, the operation fails. If the checks pass, mkfs runs on the target volume with disk layout Version 8. The block size for the target file system is assumed to be the same as the source file system. After the mkfs command completes, the source file system is unmounted and the target file system is mounted in its place. The source file system is mounted underneath the target file system. After this operation completes, the user can start the application.
status	Shows a detailed status of the migration for the specified file system, or all file systems under migration. The fsmigadm utility displays the following details: o Source device o Target device o Number of files copied o Total file data copied o Current status of the background copy operation (in progress / paused / killed / completed)
throttle	Throttles the background copy operation. You can speed up or slow down the background copy operation based on production needs. The value is in MB/s.

-l logfile	Specifies the location of the logfile generated by the analyze operation. If the location is not specified, then fsmigadm generates a file with a unique name based on the mount point and stores the file in the /var/log directory by default.
-o mount_options
	Specifes the mount options for the target file system. During migration, fsmigadm does not support the following mount options: qio, snapof, ckpt, cluster, remount, and quota.

mount_point
	Specifies an application-visible mount point.
target_device
	The device for target VxFS file system.
throttle_speed
	Specifies throttle speed.

The fsmigadm command returns 0 on success, and non-0 on failure.

EACCES	The user does not have permission to perform the online migration operation. Only privileged users can perform a file system online migration operation.
EIO	An I/O error occurred on the device; the online migration operation cannot continue.
ENOSPC	The target file system does not have enough space to hold the data and metadata of new file system.
EROFS	The file system is mounted as read-only; the online migration operation cannot be performed on a read-only file system.

To start migrating the device /dev/vx/rdsk/s03dg/vol1 of the /appdata file system to VxFS:

# fsmigadm start /dev/vx/rdsk/s03dg/vol1 /appdata

To view the status of the migration operation of the /appdata file system:

# fsmigadm status /appdata

To commit the migration operation of the /appdata file system:

# fsmigadm commit /appdata

To abort the migration of the /appdata file system:

# fsmigadm abort /appdata

To throttle the background copy operation for the /appdata file system:

# fsmigadm throttle 2 /appdata

To pause all migration file systems:

# fsmigadm pause

Veritas Storage Foundation Advanced Features Administrator’s Guide