RAIDZ2 vs RAID6 resilvering/rebuilding

garbetjie

Honorable
Aug 27, 2012
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10,510
Hey all. Long time lurker - first time poster here :D

I know this might be a topic that has been pounded to death, as there might be enthusiasts from both sides that will fanatically support *their* choice. I still find there is some information that isn't easy to come by; which I would like to know.

As a part of our small office backup solution, we will be using Debian as the operating system (running of a USB thumb drive); with 6x 3TB Seagate drives to store backup data on.

My main question is this: do I go with these drives in RAIDZ2, or software RAID6?

From the reading I've done on each one, ZFS seems to hold the upper hand. However, with the differences between each parity method, does one provide a method of making better use of a system's resources when rebuilding a failed drive?

The system we have will be running a dual-core Celeron chip (at 2.5GHz), with 2GB of RAM. It will *only* be used a backup server - so there won't be a massive amount of activity happening throughout the day on the disks.

Has anyone had any experience on the processing power required by RAID6 or RAIDZ2? Even if so, if anyone could point me in the right direction as to where to read more on this specific portion, I'd really appreciate it.
 

PlowHouse

Distinguished
Dec 14, 2012
16
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18,510
With only a dual core system at 2GB RAM you’re going to have major performance issues. ZFS is a resource hog. I prefer ZFS over RAID6 but make sure to do your research on adjusting performance such as ZFS prefetching and setting the ZFS ARC. Even though your system is a backup server, you should try to increase the RAM to at least 4GB (the more RAM the better).