Getting to know the beast
Perhaps even more impressive than those hardware specs is the Titan's software architecture, which is easy to navigate from its browser-based management GUI. The Titan organizes storage in file systems, storage pools, and system disks. Each system disk contains a number of physical disk drives and assigns properties such as RAID level and the granularity of each storage fragment.
Storage pools bring together multiple system disks to create reservoirs of capacity from which you can create file systems. This scheme gives admins the flexibility to tune for capacity and performance but is hidden from end users who see only a large directory containing their files.
An admin can anchor file systems to a static capacity or allow them to automatically expand when a threshold is reached. Expansion can be limited to a specific capacity target per file system. Setting that hard limit makes sense because no file system can be shrunk at the moment, although according to BlueArc that feature should become available in future versions.
To help prevent runaway capacity increases, admins can define two threshold levels for file storage and separate percents for what's being used by automatic snapshots. To help admins monitor the situation, the management GUI displays a color-coded bar showing the percent used, and the system generates a warning when one of those thresholds is reached.
For a more selective approach to monitoring capacity, admins can use the quota features of the Titan. Quotas allow you to define user directories (Virtual Volumes in BlueArc lingo) and their limits according to capacity or number of files. As with BlueArc's file systems, you can set soft and hard thresholds for user directories. You can also set limits per user and per group.
I was immediately comfortable with the Titan management GUI, and the capacity monitoring features of the system are adequate to prevent runaway expansions. But if you need more control over data content, such as the ability to limit or prevent storage of certain file types, you'll have to use third-party applications.
Setting limits on the space used by snapshots may seem overly cautious until you realize that the Titan can take 1,024 snapshots for each file system, either manually or driven by a schedule. Considering that you can define more than one hundred file systems, snapshots could quickly become a significant part of your storage allocation.
The Titan makes it easy for users to recover lost files from a snapshot. Users can access a read-only folder hidden in their own directory to retrieve lost files without having to wait for an admin's help.