Quantum DXi4510, Руководство пользователя

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Chapter 6: DXi4000 Replication
Understanding Data Replication
Quantum DXi4000 User’s Guide 83
Caution: A saved snapshot is necessary to recover your data at a
later time. For this reason, it is not enough to simply enable
replication for a share. You must also configure a
replication schedule (recommended) or perform manual
replication on a regular basis to send snapshots of the
share to the target system.
If the source system ever becomes unavailable, you can recover the
share on the target system using a saved snapshot. After you recover a
share, it is recreated on the target system and is available for use. Once
the source system becomes available again, you can perform a failback
operation to restore the share to its original location.
Directory/File Based
Replication
Like replication, Directory/File Based Replication sends data from a NAS
share to another system where it can be accessed. However, Directory/
File Based Replication differs in a number of important ways:
• Both replication and Directory/File Based Replication must be
enabled for the share.
• A unique Sync ID is used to associate the replicated share on the
source system with the share that will receive the replicated data on
the target system.
• You do not need to schedule or manually perform Directory/File
Based Replication through the remote management console.
Instead, replication is triggered when a file is closed or a period of
time after it is modified (NAS shares).
Note: For CIFS shares, a file is replicated immediately after it is
closed. For NFS shares, a file is replicated after it has been
idle (not accessed) for several minutes.
• After directories and files are replicated using Directory/File Based
Replication, they are automatically recovered on the target system
and are immediately available for use. There is no need to first
recover the share to access its data.
• You must manually initiate a synchronization from the source
system on a regular basis. Synchronizing ensures that the contents
of the source share are exactly the same as the target share by
propagating deletions from the source system to the target system.