The ONTAP Snapshot is used
to create Recovery Point snapshots of a destination. The destinations are UNC path,
iSCSI LUNs to a NetApp
file server in case of Windows and a mounted NFS export in case of Unix.
Install the Software -- Install CDR software on the source and
destination computer(s). For instructions, see Deployment
- ContinuousDataReplicator.
Configure the Agent -- For Unix, right-click the Agent and select
Properties. In the
Authentication tab,
click Filer Management. From the Array management dialog box, add the credentials for the
user account to be used when using ONTAP snapshots.
Ensure that you provide the fully qualified domain name or TCP/IP address of the
filer in the Control
Device ID field.
Configure the Replication Set
-- For Windows, for a destination computer to use ONTAP Snapshot to create Recovery Points,
right-click the Replication Set on the source computer and select Properties.
In the
Replication Options tab, select ONTAP in the Select Snap
Engine Type for Recovery Point Creation section. To access the filer,
specify user account information in the General tab of the replication set
properties on the source computer. For Unix, the Snapshot
engine is automatically selected based on your destination.
For Fan-In Recovery
Points on Windows, right-click the ContinuousDataReplicator Agent on the
destination computer and select Properties. In
the Fan-In
tab, click Recovery Points tab and select Use ONTAP snapshot for ONTAP LUN destinations
option, to create ONTAP snapshots on iSCSI LUN. If your destination
is NetApp filer and destination path is UNC path, ONTAP Snapshot engine is
automatically selected.
To access the filer, you must specify the user
credential details as follows:
For Recovery Points, from the General tab of the replication
set properties on the source computer, specify the credentials
for the user account to be used when using ONTAP snapshots.
For Fan-In Recovery Points, from the General tab of the
agent properties on the destination computer, specify the
credentials for the user account to be used when using ONTAP
snapshots.
For more information about configuring, creating, and using Recovery Points
with CDR, see Recovery
Points.
Recovery Points created using ONTAP Snapshot can be backed up. For more
information about performing backups of Recovery Points, see
Backups of Recovery Points.
Data from Recovery Points created using ONTAP Snapshots can be recovered in a
variety of ways. For information on recovering data from ONTAP Snapshot, see
Recover Replicated Data.
Consider the following, if snapshots are created when a LUN is cloned:
Delete snaps in the reverse order they were created in. If you have a
situation where the busy snap is no longer mounted but is still shown as
busy, then all additional snaps on this volume created while that snap was
mounted will need to be deleted so that this snap will no longer be busy.
See the ONTAP 7.3 note below to avoid this dependency.
Do not mount a volume and create another snap for the volume. To avoid
this snapshot dependency, do not manually create a snapshot of a volume
while you have a snapshot mounted.
For NetApp ONTAP version 7.3, there is an option to enable the system to
only lock backing Snapshot copies for the active LUN clone. If you do this,
when you delete the active LUN clone, you can delete the base Snapshot copy
without having to first delete all of the more recent backing Snapshot
copies.
This behavior in not enabled by default; use the
snapshot_clone_dependency volume option to enable it. If this option
is disabled, you will still be required to delete all subsequent Snapshot
copies before deleting the base Snapshot copy.
We recommend that you enable this option but if you are using any
other applications on the LUN, review the documentation
for this feature for other impacts. As with this option enabled, if you
delete the snapshot that had originally cloned the LUN, then you cannot use
“snap restore” to restore the clone from one of the later snaps. If this volume options
is later turned off on the volume, then you may have difficulties deleting
snapshots because the dependencies will again be enforced.
CDR on Windows supports iSCSI LUNs as destination for NetApp filers. When iSCSI LUN is
used as destination to create Recovery Points, you must specify user
authentication details. The user information must be specified either in the
General tab of the replication set properties on the source or in the
General tab of the agent properties on the destination.
The user should have permission to access the
filer.
One snapshot is created per CIFS share. If E:
is mapped to \\me\CDR_1 and
D: is mapped to \\me\CDR_2, there will be two snapshots created on the file server
even if both UNC paths end up on the same volume. It may be useful, using
this same example, to instead map D: to
\\me\CDR_1\D and E: to
\\me\CDR_1\E, so that only 1 snapshot is needed.
Snapshots on the NetApp file server will be named
cvcdr_<timestamp>_<number>
, for example cvcdr_1189118004_1. If there are multiple shares used, then one
snapshot will be created for each share and the <number> will be incremented for
each. The corresponding CIFS share on the snapshot will be named
1189118004_1.
This share will be in exactly the same place as the share being replicated to,
meaning for example that if \\me\CDR_1 is for path
/vol/myvol/dir1/dir2, then CIFS share
1189118004_1 will be on
/vol/myvol/.snapshot/ cvcdr_1189118004_1/dir1/dir2.
NetApp file server destination should be a NTFS qtree.
It is recommended that you add the local mount path of the filer to the
list of FS to be auto-mounted on reboot. For instance, on AIX you need to
add it to /etc/filesystems file and set the
Mount to true. This will ensure that if the
destination machine gets rebooted, the source machine will continue to
replicate to the destination path on the filer and all the CRP snapshots
will be automatically mounted.
To avoid the creation of additional folders on the destination machine,
it is recommended that you turn on the nosnapdir option on the volume. To do
so, run the vol options <volname> nosnapdir
command on the ONTAP console.
To perform a data protection operation using this Agent a specific
Product License must be available in the CommServe® Server.
Review general license requirements included in
License Administration. Also,
View All Licenses provides step-by-step
instructions on how to view the license information.