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.
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 conguration 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 conguration, both
FluidFS clusters can act as a failover target for each other.
After you have xed the reason that caused the original FluidFS cluster to fail, you can manually fail back to the original conguration 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 congure 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 dierent 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 dened on it.
Managing the DNS Conguration 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.
FluidFS Administration
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