Constant Thinking

Posts tagged "raid-z2"

2 posts
vdevs.jpg

A Closer Look at ZFS, Vdevs and Performance

Obsolete | In Solaris
| 14 minute read

When looking at the mails and comments I get about my ZFS optimization and my RAID-Greed posts, the same type of questions tend to pop up over and over again. Here’s an example from a reader email: “I was reading about ZFS on your blog and you mention that if I do a 6 drive array for example, and a single RAID-Z the speed of the slowest drive is the maximum I will be able to achieve, now I thought that ZFS would be better in terms of speed. Please let me know if there is a newer ZFS version that improved this or if it does not apply anymore.” This is just an example, but the basic theme is the same for much for the reactions I see: Many people think that RAID-Z will give them always good performance and are surprised that it doesn’t, thinking it’s a software, an OpenSolaris or a ZFS issue.

In reality, it’s just pure logic and physics, and to understand that we should look a little closer at what vdevs are in ZFS and how they work.

Disks in a circle. How cute.

Home Server: RAID-GREED and Why Mirroring Is Still Best

Obsolete | In Home Server
| 11 minute read

After moving my blog to its new home and getting my hands dirty with Drupal, it’s time to continue my series of blog articles about setting up a home server. Remember? We talked about home server requirements (no link, sun.com no longer exists), then I presented to you my small and energy-efficient, still ECC-protected and powerful AMD-based home server (no link, sun.com no longer exists). Now it’s time to explore some different ZFS disk pool RAID strategies.