Can I power my TrueNAS applications using only a single NVMe SSD, or do I need to replicate them?
Can I power my TrueNAS applications using only a single NVMe SSD, or do I need to replicate them?
I'm setting up my initial TrueNAS system and planned to use one open box with a 1.92TB Samsung PM9A3 NVMe SSD for running my applications.
Questions:
1. Should I really duplicate my app NVMe SSD and have two copies?
2. What capacity should the NVMe SSD be, considering my needs? (details below)
The urge or concept of "mirror" is influenced by various factors, including reflection, identity, and self-perception.
I understand many people often try to mirror, but I believe it's not always the best approach for every situation. You'd only need to use mirror drives for apps if they're essential or if you're keeping crucial data there. On my TrueNAS unit, all apps are on a single SSD, and most of them point to the storage pool rather than being critical. For me, SSDs are too costly to rely on through mirroring, so I'm avoiding it completely. I plan to rebuild my storage soon with a 6x HDD RAIDZ2 setup, using two 118GB Optane drives for metadata mirroring. Outside of that, nothing is being mirrored in my system.
I wasn't certain if it was necessary, but it seems unnecessary now. I'll choose the 1 x Samsung PM9A3 960GB for the app pool and back it up on my HDDs.
The mirrored metadata vdev is interesting to me; I wanted to implement it because I believe it can significantly speed things up.
This is my first TrueNAS installation, I'm still learning, and the data I'm backing up is important, so I'm mainly concerned about losing the metadata vdev pool and all access to my files.
That would be a solid approach.
If I weren't relying on enterprise Optane drives, I'd likely opt for at least a triple mirror setup. This environment demands strong redundancy because the pool would become unusable without the metadata. For initial projects, it might make sense to skip this and experiment if you're setting up another pool later.
I took a look at those Optane drives and wasn't familiar with them. Their performance seems impressive. It appears they're priced around $60 for a 256GB unit, which might be a bit steep.
How much space are you using on your 118GB metadata drives? And could you share what the metadata includes? (I was thinking about how much storage I'd need for a large photo and video library—like 1TB—and what that would look like.)
The current configuration consists of five 18TB HDDs in RAIDZ2, about 71% full, with metadata special at roughly 40% utilization. A large amount of random data is stored across the pool, including music, movies, and various files. These are not Optane drives but hybrid NAND/Optane units; using them would be undesirable. Optane drives are extremely costly per gigabyte (around $60-75 for 118GB), and their performance has declined since they were discontinued.