Migrating the vFiler unit by copying data

When to use this section

You should read this section and perform the instructions provided in this section if you want to migrate a vFiler unit by copying data from a physical (source) storage system to another physical (destination) storage system. You might want to copy data from one storage system to another to maintain a backup copy of the data so that if the primary disks fail or the data on them becomes inaccessible, you can use the backup copy to restore services to clients.

Before you start

Before you begin the migration, make sure the following are true:

You have performed all the preparation steps listed under Storage checks and actions and Network checks and actions.
SnapMirror is licensed and enabled on both the source and the destination storage systems.
The source and destination storage systems are on the same subnet.
Note
If the storage systems are not on the same subnet, you need to run setup (and cifs setup if necessary) on the new vFiler unit after the migration to configure authority servers as specified on your worksheet. See If you have moved the vFiler unit to a different subnet or Windows domain for details.
The source and destination storage systems can communicate with each other over the network (for example, by means of DNS lookup or entries in /etc/hosts).
If any of the source qtrees or volumes contain LUNs (virtual disks), the destination storage system is running a version of Data ONTAP that supports virtual disks.

If the source vFiler unit owns iSCSI LUNs, the destination vFiler unit must be running a version of Data ONTAP that supports iSCSI LUNs on vFiler units
The destination volumes are online and writable.
You know the source storage system's administrative ID and password.

How migrating a vFiler unit affects clients

If you migrate a vFiler unit to another storage system on the same subnet, you see the following effects on clients:

NFS volume-level mounts move transparently.
NFS qtree-level mounts need to be remounted.
CIFS clients experience the equivalent of a reboot.
LUN access continues uninterrupted.
Although an iSCSI host is briefly disconnected from the source vFiler unit, an initiator hides this brief disruption from applications accessing the LUNs. To the applications, access continues without interruption.

For information on moving a vFiler unit to a storage system on a different subnet, see If you have moved the vFiler unit to a different subnet or Windows domain.

Attention
The procedure that follows destroys the original vFiler unit after replicating it on the destination storage system. If you want to leave the original vFiler unit intact and create a backup copy of it for disaster-recovery purposes, use the procedures listed under How to create, activate, or delete a disaster-recovery vFiler unit instead.

Migrating the vFiler unit by copying data

To migrate the storage system by copying data from one vfiler unit to another, perform the following steps.

Note
The following procedure uses the vfiler migrate command to migrate the vFiler unit by copying data. For more information about the vfiler migrate command and various options available for the command, see the na_vfiler man page.

Step	Action
1	Qualify and prepare the destination storage system. Perform the checks listed in Preparing the destination storage system.
2	On the destination storage system, enter the following command: `vfiler migrate start` source_vfiler`@`source_filer Note This procedure locks up the console for the minimum amount of time. If this is not a concern for you (if you want to let the job run overnight, for example) you can perform the migration with a single command: `vfiler migrate` source_vfiler`@`source_filer If you do this, skip Step 5and Step 6. You can also specify the administrative ID, password, and IP address information in this command. For more information, see the na_vfiler man page.
3	Respond to the login prompt with a valid administrative ID and password for the source storage system.
4	Respond to the IP address and binding prompts, using the addresses you entered on the "new interface" lines on the worksheet.
5	Monitor the progress of the migration with the following command: vfiler migrate status source_vfiler@source_filer Note The `vfiler migrate` command might take some time to complete, especially if a source qtree has many millions of inodes.
6	When the `status` command reports that SnapMirror has replicated all the storage units of the source vFiler unit, complete the migration by entering the following command: vfiler migrate complete source_vfiler@source_filer Note If you want to cancel the migration, you can do so now by issuing the following command on the destination storage system: vfiler migrate cancel source_vfiler@source_filer This destroys the destination vFiler unit and removes the SnapMirror and other migration-related configuration information from the source vFiler unit. Note If the `vfiler migrate complete` command reports that the process cannot complete, wait a few minutes and then enter the same `vfiler migrate complete` command again.
7	If you copied quota information into the destination storage system's /etc/quotas file (see Step 8 of Preparing the destination storage system earlier in this chapter) activate the quotas on that storage system. For each volume you are activating quotas on, use the following command: quota on volume_name
8	Make adjustments on the clients. You will need to remount qtrees, but volume-level mounts should be intact.
9	If you have moved the vFiler unit to a different subnet, follow the steps in If you have moved the vFiler unit to a different subnet or Windows domain.
10	If the vFiler unit's storage units contain iSCSI LUNS, reconfigure iSCSI authentication. See the Block Access Management Guide for instructions.

What the vFiler unit migrate commands do

The vfiler migrate start command does the following:

Checks that the destination storage system is capable of receiving the source data.
Configures and runs SnapMirror to copy the data from the source to the destination vFiler unit.
Saves the IP configuration and binding information you supply (see Step 4 in Creating the vFiler unit).
Saves the quota information from the source vFiler unit's /etc/quotas file.

The vfiler migrate complete command does the following:

Stops the source vFiler unit.
Updates the data on the destination vFiler unit.
Breaks the SnapMirror relationships.
Configures IP bindings on the destination vFiler unit according to the information you provided to the vfiler migrate start command, adding the destination IP information to the destination /etc/rc file. (Any IP information that pertains only to the source vFiler unit is removed from the destination /etc/rc.)
Configures any quota information saved by the vfiler migrate start command.
Destroys the source vFiler unit.
Brings LUNs online using migrated LUN maps and igroups.

If you have moved the vFiler unit to a different subnet or Windows domain

If you have moved the vFiler unit to a different subnet, you might need to configure the network servers and make adjustments on the clients. If you have moved the vFiler unit to a different Windows domain, you might also need to modify data-file security attributes.

Perform the following steps on the destination vFiler unit.

Step	Action
1	To configure NIS and DNS servers, run `setup`.
2	To change the name of the Windows domain controller, use the `cifs prefdc` command.
3	To change the Windows WINS server, run `cifs setup.` Note If the Windows domain has changed, you might need to change the permissions on the Windows data files to allow your users the same access they had in the old domain.
4	To change the trusted host, do the following: a. Edit the vFiler unit's /etc/hosts.equiv file, adding the name of the trusted host for administering the vFiler unit. (This is the hostname you entered on the worksheet as "new trusted host.") Note If the trusted host is a Windows system, or if it is a UNIX system and the trusted user is not the root user, you need to add the user name as well: for example, `adminhost joe_smith.` b. Add the path to the root volume and the name of the trusted host to the vFiler unit's /etc/exports file. Example /vol/vol0 access=adminhost, root=adminhost
5	Make adjustments on the clients. These include remounting volumes and qtrees.

Migrating the vFiler unit by copying data

When to use this section

Before you start

How migrating a vFiler unit affects clients

Migrating the vFiler unit by copying data

What the vFiler unit migrate commands do

If you have moved the vFiler unit to a different subnet or Windows domain

Example