In the first part of this article we discussed some grave statistics regarding what may happen to your company if you lose some or all of your data. We then discussed the three primary backup methods that can be used to ensure your data gets backed up. These methods are tape / media, cloud, and disaster recovery / business continuity (DR/BC).
Each method has its own pros and cons and down time in the event of a device failure. First we will look at the pros and cons and then we will look at the potential down time that may be experienced with each method.
Pros and Cons of Different Methods of Data Backup
Tape / Media Based
The advantages of using tape are resilience, dependability, durability and portability. Tape backups can be stored for decades leading to a much longer shelf life than any other media. Magnetic tapes are also easily replaced or added. Likewise, tapes are also easier to store offsite in a secure facility.
The cons of tape backup include time, costs, and storage capacity. Tapes are one of the slowest media’s to write to because they are sequential, not random such as hard drives. Also, tapes are prone to human error, such as not putting in the correct tape for the correct day or replacing a tape once the backup has finished. Tapes are susceptible to data growth. If you originally purchase 14 72GB tapes (a two week rotation), and your companies data grows beyond that, all 14 tapes will need to be replaced.
The advantages of disk or flash based backups are also dependability and durability. Unlike tape, disk based backups can be more cost effective. Per byte, hard drives are usually more costs effective than other media such as tape. Speed is also another factor. Flash and disk based backups complete much faster which can greatly speed up the backup time for large data sets.
The disadvantages of disk or flash based backups are expandability and portability. Similar to tape, if you are backing up to a flash drive, and your backup data set size surpass the capacity of the flash drive, then a new flash drive will need to be purchased. With hard drives, storing the device offsite may pose some issues, especially if the disk is internally hooked up to the computer.
The advantages of a cloud based backup solution is that you typically only need to download and install the backup software to the device that you want to back up. Once you choose the data that you would like backed up, the software handles the rest. Typically no additional hardware is required to perform the backups. This helps reduce human errors such as not replacing the backup tape and requires significantly less administration.
The disadvantages to cloud based backup solutions are two fold. First, if you have low bandwidth to the internet, backing up large amounts of data may take an enormous amount of time, and could even take more than 24 hours to complete. The second disadvantage is accessibility to your data. If the backup provider or your ISP should go offline for any reason, your backup would not be available until the respective provider comes online.
Many cloud based backup providers also offer a beneficial service called a local vault. A local vault stores some or all of your backup on media within your organization. This can either be a copy of the data stored at their facility or a subset of your backup that is not critical enough to be stored offsite. The local vault can help reduce the cost of the hosted backup as well as increase availability of your backup incase your internet connection was to go down or your backup provider was offline.
Disaster Recovery / Business Continuity Based
The advantage of DR/BC based backups is that an entire snapshot of the server is taken at predetermined points in time. The resulting image can be used not only to restore data, such as critical files, but in the event that your server fails, and will be offline for an extended period of time, the image of the server can be ‘spun up’ as a virtual server, and your company can continue to work as if the disaster never occurred. Then when the server is repaired or replaced, the running image can be restored to the hardware so no data is lost.
The disadvantage of DR/BC is cost and complexity. Usually the backup solution needs to run on dedicated hardware and provisions need to be made to replicate the images to an offsite location. Many backup providers already have pre-built solutions put together. These solutions either have a large upfront cost or a higher monthly fee than the previous two backup methods.
Working with virtualized servers can become very complex. When you take an image of your current server and try to virtualize it on foreign hardware, many problems can arise that would prevent the image from booting correctly. Trying to correct these issues can be an extremely time consuming and complex process.
Downtime is a critical factor in choosing the correct backup method for your organization. Each company has a pain point on how much down time they can experience before it affects their bottom line.
A DR/BC backup solution will have the least amount of downtime associated with it due to its virtualization technology. With the DR/BC solution, a virtual copy of your server can be activated and your organization can get back to work as if nothing happened. Your company could work on this virtual server for several days before the working image is restored to the repaired hardware. Even in the event that a disaster struck your building, a virtual server can be activated in the cloud (if your DR/BC service supports this) and critical data can be accessed so your company is not completely crippled.
Depending on the type of disaster, tape/media and cloud based backups each have their own downtime associated with them. With cloud based backups, if you loose connection to the internet, restoring a file or even the entire server would be impossible. Your organization would need to wait until your backup can be sent to you via some type of removable media (if the vendor supports this). With tape or flash drive backups, files can be restored only if the media is available. For example, if your office was to burn down, and all backup media was in it, then data would most likely not be restorable. With tapes, more downtime may be experienced in the event of a total server failure due to the fact that a tape drive is needed to read from the tapes. With disk or flash drive backups, most other computers can read this media, and at least critical files could be restored to allow the company to work, although in a semi crippled fashion.
In part three of this article (coming next week!), we will discuss how to choose the backup method that is correct for your business as well as how to create a business continuity plan to help better prepare your organization for a disaster.
Preparing for a disaster:
Part 1. What if you were to come into your office one morning and found that your server was off?
Part 2. What are the pros and cons of 3 primary primary data backup methods?
Part 3. T Learn how to choose the correct backup method for your organization.