Fujitsu ETERNUS CS800 S6 User Manual page 342

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 or partition. You must also
configure a replication schedule (recommended) or perform manual replication on a
regular basis to send snapshots of the share or partition to the target system.
If the source system ever becomes unavailable, you can recover the share or partition on
the target system using a saved snapshot. After you recover a share or partition, 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 or partition to
its original location.
Directory/File or Cartridge Based Replication
Like replication, Directory/File or Cartridge Based Replication sends data from a NAS share
or VTL partition to another system where it can be accessed. However, Directory/File or
Cartridge Based Replication differs in a number of important ways:
Both replication and Directory/File or Cartridge Based Replication must be enabled for
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the share or partition.
A unique Sync ID is used to associate the replicated share or partition on the source
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system with the share or partition that will receive the replicated data on the target
system.
You do not need to schedule or manually perform Directory/File or Cartridge Based
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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), or when a
tape cartridge is unmounted (VTL partitions).
For CIFS/SMB 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..
To optimize the replication process, deduplicated data is continuously sent
in the background from the source system to the target system. Any
remaining data is sent (along with metadata) at the time a file is closed or
a tape cartridge is unmounted.
After files or cartridges are replicated using Directory/File or Cartridge Based
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Replication, they are automatically recovered on the target system and are
immediately available for use. There is no need to first recover the share or partition
to access its data.
Deletions are automatically propagated from the source system to the target system
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in order to free up space on the target. In addition, you can manually initiate a
synchronization from the source system at any time. Synchronizing ensures that the
ETERNUS CS800
11.1 ETERNUS CS800 Replication Overview
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