Backups: Desperately Important

[wblock]

Just a quick note to remind people again that drive redundancy is not a backup. Keep copies of your priceless data in separate physical locations. Bad things can happen, including but not limited to fire, flood, theft, locusts, shark attack, fat fingers, skinny fingers, chicken fingers, and apoplexy.

An additional copy of your data on a $50 external USB drive stored at a different site is better than nothing. Multiple copies of your data automatically replicated from your FreeNAS system to other systems at other sites are even better.

Please take this moment to recognize that system failures can happen to anyone and consider what you will do when it happens to you. Then take steps to make it much less painful. It's insurance, and if you do things exactly right and are very lucky, you'll never need to use it. If life happens in the meantime, it will be less stressful for you, your family, and your friends, including us.

Thanks!

 

[rs225]

This is a great time to remind everybody that Raidz is an availability feature, not a durability feature. (aka RAID is not a backup)

And a great way to really hammer this point home is to recommend raidz1 to everybody. Raidz2 are for very large vdev or remote systems that may have to run degraded for a long time. Raidz3 is for trips to Mars.

A raidz1 user is a careful user who keeps backups.
A raidz2/3 user thinks he has beaten the fates and has none.

If keeping backups is too much data, at least put your more important data is a special dataset that you do keep backed up.

As further recap from long-ago threads, a raidz1 is protected from 99% of disk failure scenarios. A raidz2/3 is at best increasing that protection an additional 1%. The double-disk resilver failure argument is false, because every scrub is equivalent to a resilver, therefore, a regularly scrubbed pool is statistically NOT going to have a drive failure triggered by a resilver.

If URE errors or drive failures were as common as some people claim(e.g. "RAID5 zobs in 2009"), they would show up in every scrub.

 

[Tim1962]

My motto is that you can have raidz593 but if someone steals your server, it means nothing.