One of my criticisms of ZFS is that it's not flexible: Once you set up a dataset, you're pretty much stuck with it. But this isn't entirely true: You can add a mirror or stripe to an existing pool without destroying the data. Since this is quite a common operation, I decided to write it up for posterity. A Very Simple ZFS Pool Let's say you built the world's most basic ZFS … [Read more...] about Add a Mirror to an Existing ZFS Drive
ZFS should have been great, but I kind of hate it: ZFS seems to be trapped in the past, before it was sidelined it as the cool storage project of choice; it's inflexible; it lacks modern flash integration; and it's not directly supported by most operating systems. But I put all my valuable data on ZFS because it simply offers the best level of data protection in a small … [Read more...] about ZFS Is the Best Filesystem (For Now…)
Hard disk drives encounter errors from time to time, so it's a good thing that most have the ability to recover data anyway. But RAID systems usually have their own error recovery capabilities and can be thrown off when a hard disk pauses I/O. So it's a good idea to use hard disk drives that allow you to disable or limit error recovery in RAID systems. Error Recovery … [Read more...] about Turn Off Error Recovery in RAID Drives: TLER, ERC, and CCTL
I've dabbled with FreeNAS in the past and had such a great experience with pfSense (a similar FreeBSD-based project) that I jumped in with both feet on my home office server build. But my initial impressions were, frankly, terrible. I've got the system running and stable now, but I'm finding it difficult to recommend FreeNAS at this point. 2017 Update: I'm still running … [Read more...] about FreeNAS First Impressions
A few years back, I wrote an immensely-popular series of blog posts outlining the four things that were holding storage system performance back, and the ways to fix them. At the time, I created some presentation content to go along with these posts, and even considered pulling them into a white paper, but nothing came of that. Now, however, I'm pleased to announce that my Four … [Read more...] about The Four Horsemen of Storage System Performance Are Coming To Life!