Data Protection
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Titan SiliconServer
Data Protection Overview
The data protection attributes of the file system (file system consistency and NVRAM protection)
can be configured by the system administrator to ensure that all the data on the system is
protected. The data protection services include snapshots, anti-virus support, data replication,
NDMP backup, etc.
The Titan SiliconServer uses a unique hardware based File System, which delivers outstanding
performance, and, at the same time, preserves the data in the event of an unexpected failure
such as a power loss.
Checkpoints
To guarantee File System consistency, complete and consistent File System images
(“checkpoints”) are periodically written to the storage subsystem. Additionally, any File System
modifications that have started and are not included in an on-disk checkpoint are buffered in
NVRAM. An acknowledgement for an operation is only returned to the client once all resulting
File System modifications have been buffered in NVRAM and also mirrored if in a cluster.
Titan provides
statistics
to monitor NVRAM activity.
The checkpoint process ensures that all file system metadata is always internally consistent
even after a system failure. In order to ensure File System consistency, a File System
"checkpoint" is written to the storage at regular intervals. Every checkpoint is internally
consistent. In the event of a system failure, the file system can be "rolled back" to the last
successful checkpoint thus ensuring that file system consistency is never lost.
Protecting the Data from Failures
Every request to modify the File System is buffered in NVRAM until the checkpoint containing
the modification has been successfully written to the storage. If a system failure occurs, the File
System can be rolled back to the last successful checkpoint and then any requests buffered in
the NVRAM can be replayed. This ensures that once modification requests have been
acknowledged by the server (to the client) they cannot be lost.
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Data Protection
