03/16/2017 by Michael Andersen 0 Comments
One Backup Isn’t Enough
One Backup Isn’t Enough
Having a backup is much better than not having any. Having just one, though, is a risky approach. Whether it’s a local backup or cloud-based, any single backup can be insufficient. A redundant approach is far safer; it’s unlikely two or more backups will fail at once. Neither onsite nor offsite backup is enough by itself.
The easiest way to back up files is to copy them to a local drive with an automated process. If that’s the only backup, though, it carries several risks.
- Backup media can fail. A disk drive or tape can develop unexpected errors. They might not become apparent for a long time. The system seems to perform backups successfully, until you try to recover the affected files. Then you find you have damaged files, or nothing at all.
- A disaster can wipe out backups. A catastrophe such as a hurricane or fire can wipe out everything in the office, including the backups. At least one copy needs to be at a safe distance, where the same event won’t affect it.
- Ransomware can mangle files on attached storage. Ransomware encrypts files on a computer to force its owners to pay to recover them. In order to keep victims from easily restoring from a backup, it also attacks files on any attached drives if it can.
- Human error can ruin a backup. Users can access local backups as file systems. They can delete files from it by mistake. Manual backups are especially error-prone; backups that are supposed to happen every day might not, or they might leave out important files.
- The available storage might not be sufficient. If the backup volume fills up, backups might stop working without being noticed. Older files will still be there, but new and changed files won’t get backed up.
- RAID isn’t a redundant backup. A RAID (redundant array of inexpensive disks) system is a useful storage device, but it doesn’t count as more than one backup. The disks are all in the same box, so the whole device can fail at once. In spite of the name, not all RAID configurations even have internal redundancy.
Reasons cloud backup isn’t enough
If you have just one backup, an offsite cloud backup is better than a local one, but a single cloud backup isn’t enough by itself either.
- The backup agreement could terminate. There might be a bookkeeping error, the company might think you’ve violated the terms of service, or you might forget to pay the bill. The company might go out of business or stop offering the service you’re using. Normally someone should notice this and take action, but should a company stake its data on not making a mistake?
- Bandwidth might not be sufficient. The Internet connection might not have a high enough bit rate to keep up with a full backup. It might be necessary to exclude some files so that the backup won’t fall behind. These files may be less important, but they should still have some level of backup.
- Backup software could stop working. An offsite backup works only as long as the local software does. A software upgrade might break it, or a configuration error could keep it from reaching the cloud service. A long time might pass before anyone notices that the backup just isn’t happening.
- Cloud services can become unavailable. The Amazon S3 outage served as a reminder that even the most respected cloud services sometimes have outages. An Internet access failure or a DDoS attack can make a remote service unreachable for hours. When things are going badly on the Internet, a business can be under extra pressure to keep performing. That makes having a good local backup important.
Back up by the 3-2-1 rule
All forms of backup have their risks, and strategic variety will keep any single failure from ruining everything. The 3-2-1 rule is a widely recommended approach:
- Have three copies of your data (including the original).
- Keep them on at least two distinct media.
- Store one of them offsite.
For critical data, having even more copies doesn’t hurt. For standard practice, having both onsite and cloud backup provides a high level of safety. Both of them should get regular monitoring to make sure they work. Contact us to learn how we can help you to set up a backup strategy that will give you the confidence you need.