We often face the question – how much backup is enough backup? Maybe I need just a little more… Is there ‘too much’ backup?
When it comes to backup – you are better safe than sorry. But when you are on the safe side, still you have a wide range between not-nearly-enough, to just about right, and all the way to i-am-loosing-my-pants-in-storage-costs-here. To avoid the 2 bad situations, and to find the sweet spot, we researched and experimented and here are the conclusions.
First, The factors
These factors effect the quantity of needed backup:
- What type of site is it? A business blog / Personal blog or an e-commerce store? How often the content changes on the site? An e-commerce site, or a site that has often content updates, need a more frequent snapshot schedule, keeping more snapshots alive. While a business site that is seldom updated needs less frequent backups and less snapshot retention.
- How often is your client looking at the site? In case of hacker attack – will the client notice in a few hours? days? months? this effects the long-term backup strategy.
- What’s the cost of storage per snapshot in comparison to building a new site? if each snapshot is 10GB, and you have total 20 snapshots live at each moment, considering DigitalOcean charges $0.05 per GB per month, you are looking at 10*20*0.05 = $10 to backup that site per month. Each additional snapshot adds $0.5 to that figure, so adding more backup is far cheaper that handling the consequences if a backup will not be available. This is of course not always true and you might be storing more, bigger backups so your math may vary. THERE IS A LINE here and simply adding backup is not the correct answer to every situation.
So, what’s the plan?
We distinct 3 types of backups:
- Short term
- Middle term
- Long term
The short term backup is for immediate problems you find / cause. If, lets say, the client played with the site and ruined something, or the DB got corrupted, you just revert to that snapshot from 2 hours ago.
The middle term backup is for those times where you find out the site is down for a few days, having just found out why. Then you search for a backup where everything still worked, and wish for the best.
The long term is for things that go undetected, and unnoticed. After a few weeks or months you suddenly remember you had something and deleted it and now you need it back. I just hope you have backup from that time…
To work!
Let’s create 3 schedules (short, middle,long):
- Short term = multi-daily/daily backups, unto a week. Choose multi daily for ever changing sites (like e-commerce). keep at least 3 days worth of snapshots.
- Middle term = weekly backups. Let’s keep at least 1-2 of those.
- Long term = monthly backup. Let’s have a snapshot taken each month, keeping 3.
This way, you end up with 3-12 short term, 2 middle and 3 long term snapshots. Total 8-17 snapshots that protect you for a significant period of time.
Add a service that asserts that your sites are up (for instance: UptimeRobot) and minimize the chance of an undetected catastrophe even further.
So basically for the price of around 10 USD per month in storage costs, we’ve created a system that should keep us safe in the event of VPS trouble or site failure.
Make sure you have the automatic snapshot transfer to a second geographic data center active and sleep well at night – yes, we do support it!
