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|Which product is best?|
Performance tuning is one of the most vexing elements of B/R. The basics of performance tuning begin with a bit of math with which the storage administrator determines how much data must be moved in what period of time, yielding a GB/min value. The following questions must be answered:
- Can the available tape drives handle the load?
- Is network bandwidth sufficient?
- Does the backup server have sufficient capacity?
- Can the disk arrays deliver the data fast enough?
There are several products that offer performance-related information. These include WysDM, TESM, Tek-Tools' Profiler Rx and Bocada's BackupReport. For example, tape drive pools can become unbalanced whereby some drives are 100% utilized and jobs are suspended while waiting for an available drive, while other drives sit idle. WysDM is one product that can identify such an imbalance. Similarly, Profiler Rx offers a module to monitor Fibre Channel switch performance, which can be useful for determining throughput bottlenecks within a backup zone.
Predictive analysis and forecasting go beyond historical analysis and performance tuning, which address the operational aspects of B/R improvement. Knowing what went wrong, and even why it went wrong, isn't enough to create a best-practice organization. Problems must not be merely solved, but avoided. Predictive analysis and forecasting addresses the risk aspect of B/R. To that extent, it's the most important element to the organization as a whole.
Predictive analysis can also ensure service level agreement (SLA) compliance. Several B/R reporting products chart when a backup job was completed against the SLA's time allocated for the job. Using this chart, administrators can project when the backup window will be exceeded. By using performance tuning analysis, administrators can identify why the window will be exceeded. Moreover, service level compliance applies to recovery analysis as well as disaster recovery planning. Several products provide "recovery preparedness" reports, including BrightStor SRM, TESM, BackupReport and QNet.
WysDM offers a unique capability whereby it can report on "deviations from normal operations" even when those operations complete successfully. For example, the program sends an alert to the storage administrator if a job takes longer than normal. After these jobs are identified, root-cause analysis can be applied to solve the problem before an actual failure occurs.
Process improvement is the key to achieving best-practice operations, regardless of how many tools, reports or forecasts are applied. Bocada specifically markets BackupReport as a product that identifies B/R process deficiencies. BackupReport ties SLA and business metrics to operational results; it also detects bottlenecks, device errors and other problems, and correlates them to specific targets. Armed with this information, an administrator can begin to refine and improve company backup processes over a sustained period of time.
Any discussion of storage issues would seem incomplete without addressing compliance-related issues, and B/R reporting products are no exception. Indeed, these products can provide a unique capability that allows organizations to perform compliance risk analysis, regardless of the regulation.
Two factors are at the heart of all regulatory compliance: data retention for a specific period of time, and the ability to restore that data if required. B/R reporting tools can help by verifying how many images of a specific data set exist, at what points in time the data images were taken (i.e., are the images continuous or are there unexplained gaps), and the likelihood of a successful restore.
Although many products have the raw capabilities to provide compliance-readiness testing, the necessary correlation capabilities and reporting elements are still being developed. Profiler Rx, BackupReport, BrightStor SRM and TESM are currently marketed as specifically having this capability at some level. Servergraph has a very interesting feature the company calls a "hog factor" report, which can tell how many images of a given data set are stored. However, the company markets this feature primarily for reducing and eliminating unnecessary save sets. It's not a huge leap to correlate this information back to a compliance-related backup set, but Servergraph doesn't currently take the final step to identify gaps in the save set coverage.
Disk-to-disk backup is rapidly becoming more popular, and B/R vendors claim to be able to differentiate between actual tape volumes and virtual tape volumes. These virtual volumes will be included during restore readiness testing in most cases. Moreover, Profiler Rx, as well as SRM products, can report on logical snapshot and other replication copies. However, they don't correlate these disk-based data copies to B/R.
Despite significant benefits associated with improved backup operations, this isn't a pain-free process. Organizations should plan for a gradual phase-in of changes, beginning with a reduction in the daily care and feeding of backup. This will reduce wasted effort and gradually improve processes. Think of it like you would an aspirin: gradual relief until the pain is gone.
This was first published in April 2005