There is an old expression in IT circles: "Don't go forward unless you've backed up." The cost of data loss can be devastating. Polaris helps you avoid catastrophe and conduct your business with confidence.
Backups are Mission-Critical
Nearly everyone has a story about when they lost data. These range from major annoyances to nightmares – no one wants the embarrassment of having to ask all of his clients for their contact information again. Data loss isn’t always from malicious acts, either. Lightning strikes, power surges, software bugs, viruses and spilt coffee can all knock a computer out of commission. The most common cause of catastrophic data loss is simple hard drive failure, which is easily prevented with a proper schedule of backups.
In the best-case scenario, loss of data means the loss of the time and effort required to generate it. This alone is a major annoyance, but if the lost data causes a deadline to be missed or other logistic difficulties, the consequences are more costly. If major hardware failure occurs, then the system used to generate that data may be lost – which can be even more expensive and time-consuming to replace.
For server-based networks, where many coworkers depend on one device, the consequences of data loss or system loss on the server are even worse. Thus it is imperative that the server is backed up on a routine basis, and that the backup medium is transported off-site to another building, and preferably stored in a fireproof box. Failure to implement such a system will eventually result in severe inconvenience, if not outright catastrophe.
Frequency dictates the risk:
Generally, the amount of data that could be lost in a drive failure is determined by the frequency of backups. Any data created since the time of your last backup will have to be recreated from scratch. It’s wise to backup important data and system files frequently in order to minimize data loss.
Archival Backups vs. Media Rotation
In order to control costs, it is often appropriate to set up a rotating schedule of backups in which we overwrite previous backups with a more modern copy of the data.
However, this approach would prevents you from accessing data that you may have accidentally deleted or files that were overwritten with incorrect data. The only solution in this case would be to have archival data. Archives are created periodically and stored offsite and replaced in the backup rotation by new storage media.
Data Only vs. Full System Backups
We have been using the term 'data' in the general sense of all of the information on your network's various hard drives. But in more precise terms, your data are the files that your employees have directly created by using the system. It is the distilled electronic essence of your entire company's efforts, and it is the primary concern of any backup strategy.
If data backups are the first priority, then a close second is backing up the system configuration of critical devices. Data files on a backup tape are not useful in and of themselves; they must be restored to a properly configured system to be useful. If the hard disk in your server fails, you definitely want to have a recent backup of your data; but, ideally you would also want a complete backup of the operating system, applications, updates, configuration details and data as well. In short, if you had an exact replica of the hard drive, then a disk failure would not necessitate a complete recreation of the system, and the significant downtime associated with such a recovery. That is the purpose of full system backups, they save labor and reduce downtime; consequently, it is wise to consider performing routine full system backups as a preventive maintenance.
Why bother with data-only backups when full-system backups can cover everything? In short, full-system backups cannot be scripted, and they require more labor than data-only backups. While it may only be financially prudent to perform full-system backups twice monthly, many of our customers prefer a more frequent schedule for data-only backups.
Comparison of Backup Storage Media
There is more to consider than just cost per gigabyte, when selecting a backup medium: What type of backup is it, data-only or full-system? How much data? How long does the backup need to be preserved? Is data security a priority? You should also consider logistical issues, such as how often will backups be performed, who will perform them, and whether the backup procedure necessitates system downtime. And the most important concern is how the data and/or system will be recovered if/when the backup is needed.
Cost per gigabyte of storage media is probably your least important consideration. Various backup tape technologies cost anywhere between $0.50 and $2 per gigabyte; optical storage, like CD-R’s and DVD-R cost around $0.50 per gigabyte; IDE hard drives cost around $1 per gigabyte. These prices will continue to drop over time, and the ‘best deal’ will vary from year to year, but there is no clear standout based on price. Magneto-optical and other exotic storage solutions are invariably more expensive per gigabyte; supposedly this premium is justified by their increased speed (we’re not impressed); in any case they are uncommon and proprietary, and therefore not well-suited to the task of long-term data storage. The bottom line is to place convenience, compatibility, security, logistics, and longevity ahead of any financial considerations, when contemplating your backup scheme.
So how do the various backup storage technologies compare? Here are some recommendations and guidelines:
Optical Drive Solutions
For data-only backups, optical drives are the preferred method of archival storage. When properly cared for, they are extremely durable, so you can expect them to be viable for decades. Secondly, optical drives are ubiquitous, so you can recover your data to virtually any computer. Moreover, you can be fairly certain that the disks that you ‘burn’ now will be compatible with future technologies. Optical disks also present a data-backup method that is easy for the end-user to apply. Finally, the storage size per disk is high enough to be quite useful, but low enough to keep individual disks cheap. This scenario is perfect for archiving data.
Tape Based Solutions
Tape drives continue to be a factor in the backup market for one essential reason: tapes hold lots of data. We acknowledge that tape drives are the industry preferred full-system backup mechanism, but we don’t think that it’s wise to use a tape drive for anything other than data-only backups (and then only when you need to routinely archive huge amounts of data). Tape drives are expensive, slow, linear (not randomly accessible), proprietary beasts that need to be properly installed and configured before they’ll do anything for you. If you’re recovering a dead server from a tape, you have to reinstall the OS to get the tape drive to work, and then restore the rest of the data and system configuration; so what’s the point of backing up the full system to a tape in the first place? And what are you going to do when the drive breaks and the manufacturer no longer supports it?
For all of these reasons, we generally steer our customers away from tape-based solutions. However, if you want to routinely archive lots of data (>12GB), or if you have an existing investment in a tape system, then we are happy to use the technology to its fullest. Tapes lend themselves well to scripting, which reduces the labor costs associated with tape backups; and tapes are very reliable archives on a 5-10 year basis.
Hard Drive Based Backups
Hard disk drives offer greater storage capacities than some of the most expensive tape drives, at commodity level pricing. Additionally, hard drives are randomly accessible and much faster than tape drives for even linear file access. And, most significantly, hard drives are bootable, so a full system backup to a hard-drive is an instant, fully functioning replacement if your server's hard drive is compromised.
In our opinion, hard drives are not suitable for archival backup (too fragile); and one should also be mindful of the labor costs involved with doing a full system backup. Nevertheless, backing up the full system to a hard disk is best medicine when you consider the potential recovery procedures. Note that mirroring the drives in a server (or utilizing other non-zero RAID levels) will ‘backup’ the server, but only locally; this won't protect against fires, lightning, viruses, hackers, or an errant system update. We suggest taking a full-system backup drive offsite at least once a month, and supplementing that with more frequent data-only backups to optical disks (or, at least the network).
