Administrator Guide

Demote a Target NAS Volume
Demote the target NAS volume to resume the original replication operations. When you demote a target NAS volume, all data
written to the recovery NAS volume while it was temporarily promoted will be lost. You can demote a target NAS volume only
from the source FluidFS cluster.
Steps
1. In the Storage view, select a FluidFS cluster.
2. Click the File System tab.
3. In the File System viewe, expand NAS Volumes and select a NAS volume.
4. Click the Replications tab.
5. Select Demote Destination.
The Demote Destination dialog box opens.
6. Click OK.
Using Replication for Disaster Recovery
You can create a disaster recovery configuration in which you replicate data from a primary FluidFS cluster to a target FluidFS
cluster that you can fail over to if the primary FluidFS cluster stops responding because of an unexpected failure (hardware,
disk, and so on). The target FluidFS cluster could either be used solely for backup for the primary site, or it could have its own
NAS volumes sharing data at the target site. In a bi-directional configuration, both FluidFS clusters can act as a failover target
for each other.
After you have fixed the reason that caused the original FluidFS cluster to fail, you can manually fail back to the original
configuration in which clients access data on the source NAS volume, which in turn replicates to the target NAS volume.
Depending on time and bandwidth considerations, failing back to the source NAS volume might take a considerable amount of
time to complete.
The following considerations apply when using replication for disaster recovery:
● If the original source NAS volume is no longer available, you can configure the recovery NAS volume to replicate to another
NAS volume in the original source FluidFS cluster. However, if the original source NAS volume is available, fail back to it.
Failing back to the original source NAS volume usually takes less time than failing back to a new NAS volume. If the FluidFS
clusters have a common snapshot, they only need to synchronize the data that changed after that snapshot was created. If
no common snapshot is available, or if replicating to a new NAS volume, all data must be synchronized.
● A single FluidFS cluster cannot contain two sets of SMB home shares. Consider the example that Cluster A and Cluster B
both have SMB home shares, for different sites or user bases. Cluster A and Cluster B both serve as replication destinations
for each other’s NAS volume that contains the SMB home shares. If the administrator tries to fail over Cluster A’s NAS
volume that contains SMB home shares to Cluster B, Cluster B rejects this operation because it already has SMB home
shares defined on it.
Managing the DNS Configuration for Single NAS Volume Failover
For single NAS volume failover, it is important that the environment is set up to properly migrate clients of the NAS volumes you
are failing over, without disrupting the clients of other NAS volumes you are not failing over.
When a NAS volume is failed over from one FluidFS cluster to another, the IP addresses that are used to access it change from
Cluster A’s IP addresses to Cluster B’s IP addresses. You can facilitate this change using DNS. It is recommended to set up a
DNS entry to correlate to each NAS volume, and change the DNS entry for single NAS volumes when they are failed over.
For example, suppose Marketing and Sales have their own NAS volumes, each with an SMB share on the NAS volumes named
marketing_share and sales_share respectively. A DNS entry named FluidFSmarketing, is created for Marketing and another
DNS entry for Sales named FluidFSsales is created. Both NAS volumes point to the same set of client VIPs on source Cluster
A. Marketing can access the Marketing NAS volume or SMB share using \\FluidFS marketing\marketing, and Sales can
access the Sales NAS volume or SMB share using \\FluidFSsales\sales.
Initially, both DNS entries FluidFSmarketing and FluidFS sales point to the same set of client VIPs. At this point, both the
marketing and sales SMB shares can be accessed from either one of the DNS names, FluidFSmarketing or FluidFS sales.
When you want to fail over a single NAS volume (for example Marketing) change the DNS entries for FluidFSmarketing to
resolve to the client VIPs on Cluster B.
Maintain a table to track which DNS entries are used to access each NAS volume. This helps when performing failover and
setting up group policies.
FluidFS Administration
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