unRAID: capacity and ease of use over performance

I’ve been looking over various NAS (Network-Attached-Storage) operating systems for some time now. Naturally, there’s two big players in the game that everyone seems to go to: FreeNAS and unRAID. Both boast a considerable user base, community add on support and a ton of customization but one big difference at a quick glance: FreeNAS, as the name implies, is free while unRAID is a pay for licensed OS. But a quick glance only shows so much.

After spending several months going back and forth, I decided to do some testing with unRAID. One of the biggest reasons was my mix of various extra hard drives I have that I wanted to use in the pool for the software RAID configuration. FreeNAS requires matching disks in pairs and I have odd sets of drives ranging from 4, 8 and 12TB capacities. I initially did some testing on an old 2U with 6 X 1TB disks to test and get used to the GUI. I then upgraded one of the disks in the array to a 2TB disk to see the process. Spoiler: stupid easy and straight forward, exactly what I want. It was time to go big on the build.

I purchased a Dell R510XD server for this project: 32GB ECC RAM, twin 6 core Xeons and 12 bay capacity; Perfect amount of drive bays and overkill on CPU and RAM for future proofing. Unfortunately, this was the beginning of a bit of a tough learning process…

Being new to software RAID, I forgot to take into account the hardware RAID card. The H700 card onboard does not support JBOD (Just a bunch of a disks) which allows an operating system to see ALL individual disks and build the software raid from this. I had to bite the bullet and order another RAID card and cables that would support the proper config. 50 bucks later, I was in business.

The initial configuration was this: (2) 12TB disks for parity, (4) 8TB disks and (5) 4TB disks for the storage pool. With the dual parity disks, this allows up to 2 disks to fail without data loss. The initial RAID parity burn in took about 30 hours which isn’t bad over all. Unfortunately, I soon found the write speeds with the software RAID to be less than stellar, something unRAID is known for. I took the next step of adding a 1TB SSD as a cache disk to mitigate this issue and can now sustain gigabit throughput on uploads without issue.

Onto the software side of things, I’ve added a few of the usual plugins (Community Applications, Calibre, Plex and others). The installs take all of 30 seconds and typically run with a dedicated docket instance, something I’ve never tinkered with prior but am quickly falling in love with for its simplicity and ease of maintenance. The software RAID seems robust, the GUI is sleek and modern and everything is snappy and well laid out. I went through and upgraded capacity replacing one 4TB disk with an 8TB (about 20 hours to burn in) and this again was quick and painless.

One quick thing of note: One of the biggest differences besides the disk loadouts between unRAID and FreeNAS is the performance. FreeNAS boasts considerably higher read/write speeds due to the way the parity works (excellent video summarizing this here). The other is that changing the array (modifying disks, adding, removing, etc) takes considerably more work and effort including CLI management of disks. As someone who’s broken a number of *NIX systems on the CLI, this was a bit of a deal breaker for me. Another difference because of the disk management being different: You can add just ONE more disk at a time to unraid, whereas FreeNAS requires matching pairs to work.

All in all, I’m shocked at how well this project has come together. With the current config, I’m at 56TB raw, 51.8TB usable capacity. The system is used both as a file dump for all my stuff and as a redundant backup system from several other systems due to its capacity. I would definitely recommending trying the software out for free and see how you like it and if it’s for you or your business.

Quick take: Slower than FreeNAS, more capacity, make sure you have a JBOD support RAID card or direct pass through on SATA.

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