by Robert Buda | Jan 21, 2013 | Backup and Recovery, Best Practices, Database
Test your Assumptions: Database Backup and Recovery
Every now and then something happens that really drives home the need to test and validate the assumptions that we have about the availability of our IT assets. I had an experience this week that brought to mind the importance of testing backup and recovery and business continuity plans.
Planning
At the beginning of each week, I look at each day’s activities and any travel that I need to do that week, and I plan out how I can be most productive each day. I find myself on the train often now between our offices in New Jersey and Boston and I have come to take my wifi service for granted. I rarely have down time when traveling that way any longer.
Last month, while traveling to San Antonio by air, I was able to use wifi in the air, just as I can on the ground on the train.
Then last week, while planning a trip by air to Austin from Philadelphia, I decided to make good use of the flight time. I planned to use the roughly four hours of flight time to get some work done that I will need for the next day.
Assuming
After I boarded the flight however, I found out that a huge assumption that I made was not correct. I found that not all airlines have wifi!
So now as I sit on the plane writing this post into a word document, I am completely disconnected from the web, from my office, from my clients!
The problem here is not that I am not connected for a few hours, it is that I did not anticipate that this might happen, and so I planned to use that time to get some important work done. I assumed that the flight had wifi, and I did not validate that assumption!
Think about what will happen if you (or your customers) don’t have access to your servers for a few hours. It can be that the connectivity to the servers was interrupted, as in my case, or that the servers are completely down, or that your database software is hanging. Ask yourself what will happen during those hours, and what you can do to avoid them in the first place.
Validating
Validating your assumptions is key to productivity. In this case, it is only one person whose productivity is compromised today, but consider the cost if your whole company is down for a few hours. What are you taking for granted?
So what does this have to do with the database?
This is a database blog, so you might be asking what this has to do with the database. In the database business, we see people fail to validate assumptions all the time. A typical (and very dangerous) assumption people make is that their database is properly backed up and ready to restore in a disaster. As I describe in this blog post, this is rarely the case. This is one of the most important assumptions for any company to validate.
If you haven’t tested your backup procedures lately we can help you validate that your database is indeed protected the way you assume it is.
by Robert Buda | Jul 14, 2011 | Backup and Recovery, Best Practices
Data Backup Advantages & Disadvantages
While tape-based backup approaches may still be optimal for long-term data retention, more and more database storage/backup administrators are moving from tape to disk technology for everyday data backup and data recovery. This is not surprising as disk is faster to write to and faster to recover from, as well as more reliable overall.
A further advantage of disk backup is the ability to perform deduplication on the data being backed up, which reduces both backup/recovery times and – perhaps most importantly – data volumes. Deduplication usually takes place during data transfer to disk. Some tools ship with the disk hardware and others with data backup software.
Many products are currently available that offer deduplication at the backup server level, which reduces network traffic between the backup server and the backup target but not between the database server and the backup server. Some products still perform deduplication post-transfer, at the backup target. While slower overall, this approach eliminates the chance that CPU-intensive deduplication processes will create a bottleneck between the backup server and the secondary storage target.
Emerging technology enables deduplication at the source (that is, on the server that hosts the database). Ultimately, deduplication will likely take place as a function of primary storage rather than as a backup/archiving function.
Like many new technologies before them, deduplication and disk-based backup/recovery fill a long-standing need for improved speed and reduced cost. But many DBAs remain skeptical, and debate exists about how best to use these solutions and their impact on data protection and the rest of the IT environment.
Data Recovery Advantages & Disadvantages
The problem many DBAs have with disk-based backup is that it is not specific to the database. Unlike traditional logical/physical, file-based backups performed with database tools, with disk-based backups the database is not “aware” that a backup is occurring, so its state at the time of the backup may be unknown. Therefore, it is important to test and confirm that your databases can recover and come back up after being backed up in this new way.
While cutting-edge disk-based recovery approaches can restore gigabytes of data in seconds, they generally can’t restore a single database table. In other words, disk-based backup doesn’t (yet) replace the logical backup methods that DBAs have used for years.
At least one product family, EMC RecoverPoint, addresses the need for logical backups by enabling “any-point-in-time recovery to protect data against loss or corruption.” RecoverPoint’s features include policy-based management. Data files can be isolated in logical groupings within the backup, to facilitate recovery of specific data.
A holistic approach to protecting your data can include both logical backups at the database level, combined with disk-based backups of your raw data.
For more information on what disk-based backup and deduplication approach is right for your business, contact Buda Consulting.
