Asigra makes no bones about it: it unabashedly advocates that companies keep all of their backup data on disk under the management of its Televaulting software. The reasons Asigra provides for keeping backup data on disk are plentiful as well: Faster backup and recovery times; elimination of tape management tasks; deduplication technologies that minimize data storage requirements for disk; and, data that is easy to copy and replicate locally and remotely. Yet if there is anything companies know about backup, it is that managing backup data and its recovery over the long term, whether it is on disk or tape, is where the complexity can start to surface.
In a recent blog entry I examined why Asigra introduced the Backup Lifecycle Manager (BLM) Archiver feature into Televaulting in order to optimize the placement of aging backup data on different tiers of disk. But the BLM Archiver does more just simply move data out of the Asigra DS-System. The BLM Archiver also carves the disk that it manages into “Staging” and “Consolidated (Disk Based)” buffer areas as shown below:
The Staging and Consolidated buffer areas within the BLM Archiver are automatically managed by the BLM Archiver so companies need to do little or nothing with these two areas in terms of day-to-day management once the BLM Archiver is configured and operational. However these two buffer areas within the BLM Archiver help to save money as well as manage the data once it is archived.
The practical application of these two staging areas initially comes into play as data is moved from the DS-System to the BLM Archiver. As data is moved into the BLM Archiver, the Staging buffer area accumulates incoming files from the DS-System over a period of time. Since the DS-System only sends obsolete data to the BLM Archiver, the influx of obsolete files to the BLM Archiver typically does not happen in bulk. 100 files may come in one day, 5 files the next day, 50 the next and so on.
In order for the BLM Archiver to ease the management of these smaller incoming files over time, it will create one large consolidated file that contains all of these smaller files. The creation of this large file only occurs when the Staging buffer fills up. The default size of this buffer is set by the user and it is usually set to at least 2 GB in size but can be larger. Once the Staging buffer fills up, these small files are consolidated and packed into a large file. At this point, the large file is moved to the Consolidated buffer. Once moved, the BLM Archiver guarantees these files (small and large) will remain stationary and not be touched again unless a restore is needed.
A situation where companies may need to restore files from the BLM Archiver is if they need to recreate what a specific server looked like at a specific past point in time to satisfy a legal discovery or hold request. In this situation, a “recoverable image” may be needed. To create this “recoverable image” of the server in question, the BLM Archiver gathers needed files from both the Staging and Consolidated buffer areas to create and present a “recoverable image” that could be used for the search. In the event companies need to keep this specific snapshot of data on another type of media (disk, optical or tape) to satisfy a legal hold, they can also copy this “recoverable image” to the media at this time.
From restorability and searching perspectives users will see little difference regardless of which buffer the files are stored within the BLM Archiver. Any search will automatically search both the Staging and Consolidated buffer areas since restorable images may consist of files from either buffer. The only difference a user may see is in the Televaulting GUI which displays the status of the file (“Staging” or “Consolidated”).
The more important difference between the Staging and Consolidated buffer areas has to do with managing the destruction of this obsolete data on disk. Companies may only want to keep this archived data three to seven years. Using the BLM Archiver, companies can set policies on each large file as it is created so that the BLM Archiver destroys the file once it expires.
Most users will essentially find the introduction of the BLM Archiver into an existing Televaulting environment a “Set it and Forget it” exercise. It gives companies the assurance they can search and recover archived data should they ever need it to satisfy some unforeseen future legal eDiscovery or hold request. More importantly, companies can also use the BLM Archiver to protect themselves from over compliance by deleting data that they are no longer bound by internal or external laws to keep. Yet a component of the BLM Archiver story that needs further examination is the options it provides for searching the data already in the archive. I’ll cover that material in a forthcoming blog entry.