Can I run my TrueNAS apps off of just one NVMe? Or should I really mirror them?

Apps and Virtualization
1

Building my first TrueNAS and was going to get 1 x open box / used 1.92TB Samsung PM9A3 NVMe, to run my apps off of.

Questions:

1. Should I really mirror my app NVMe’s, and get two?

2. How big capacity NVMe should I get, based on my uses? (Shown below)

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The apps I would run:

  • Immich (I have like 2 - 4TB of photos, and a few TB of videos. I will be doing video editing)

  • Nextcloud

  • Jellyfin (Maybe will have a few hundred movies. I don’t watch many movies, just archive older / hard to find movies, for when I do watch them, maybe once a month).

  • Maybe a few other apps I haven’t though of yet

In my home ecosystem I will also be running:

  • a powerful desktop workstation

  • a homelab server (i7-8700T w/ 64GB RAM and 256gb + 1tb NVMe)

2

You don’t have to mirror your NVMe. I don’t. However, you do need to think about your strategy for when something fails.

Personally, my home server has a single NVMe that has all my system stuff, apps, etc., and 4 HDDs in a RAIDz1 configuration with all the big data: movies/video, music, photos, PC backups, etc. The NVMe has my app configurations, caches, thumbnails, etc., but all the main data is stored on the HDD pool. The HDDs of course have much more space than the NVMe, so as a backup, I have everything on the NVMe snapshotted, and those snapshots are mirrored on the HDD pool. If the NVMe fails one day, I’ll just have to install a new NVMe, and restore the snapshots from the HDD pool onto it. Of course, this is not nearly as convenient as having a mirror, which I might do in the future, but for now it works. And of course, the data on the RAID pool is itself backed up onto other dedicated backup drives kept in cold storage, just in case they completely fail too.

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3

Just echoing what @dwolsten stated….

I recently added a pair of 1 TB NVMe drives as a mirrored pair on my TrueNAS server and migrated my apps from the HDD RAIDZ2 to the NVMe mirror. The media services (Plex for movies/tv shows/music, Kavita/Booklore for eBooks, and especially Audiobookshelf for audiobooks) benefitted from the faster access to their respective databases. The actual media content remains on the HDD RAIDZ2 and would not benefit from the faster access.

Can you run your apps from a single NVMe drive? Yes, but having a mirrored pair benefits from redundancy in case one of the drives fail.

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4

As an alternative to mirrorring, you may set copies=2 on the single drive pool to protect against a bad sector (but not full drive failure, obviously) and/or set a regular replication task to the HDD pool so you have something to restore in case of drive failure.
As much as practical, document your app installations so you have intructions to recreate from scratch as a last resort.
SSDs are generally reliable (until they aren’t, as always), so a single drive pool which does NOT hold irreplacible, critical, data may be a reasonable setup.

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5

Thanks, this seems like the most reasonable solution.

I’ll just get 1 x 960GB nvme for now.

If your one app NVMe did fail, how long do you think it would take you to restore your all of your apps to get them back up and running?

(This is my first TrueNAS build, so I’m just trying to come up with a plan for that now, I am still quite new to all of this)

6

If you make backups? As long as it takes to swap & copy over. If you make config backups? As long as it takes to swap & copy those over.

Planning for failure is planning for success. Redundancy, however, is still faster.

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7

Just stumbled over the number 960 - afaik 960GB SSD are mostly either very low end or (Patriot P310, WD Green SN350) or datacenter-class (Samsung PM9A3, Micron 7450 PRO).

I hope you want to get one of the datacenter-class ones.

If not: maybe spend the few extra bucks to get a proper consumer grade one (TLC, DRAM cache, high TBW …), maybe even one specifically for NAS use like the WD SN700.

1 Like
8

The Micron m.2 7450 PRO needs a good heatsink and a strong fan pointed at it.
Otherwise they idle at 70 C and overheat during writes.

9

I didn’t mean to recommend it. I just named some examples for low end and datacenter-class 960GB NVMe SSDs.

10

Yes, I’m looking at used datacenter-class ones. (Specifically the Samsung PM9A3, but I’m open to other suggestions)

1 Like
11

used drives in your NAS? Even if you use crystaldisk and find very low hours and test it thoroughly, you have to ask why someone sold the drive in the first place?

if your data is critical, can’t-be-lost data, best case is to go with new with a reputable drive type which has good lifetime TBW and solid Drive Writes Per Day (this is only ever an estimate) values.

Unless of course you don’t like your data… then get all the used equipment you can ebay.

12

SSDs from datacenters usually get pulled because of upgrade cycles. Not because they are broken.
If you like your data, do backups.

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13

It may depend a little on the App. Plex, for example, if you leave the media in your storage pool, and everything else on the NVME, then if the NVME fails, you just replace it, reinstall the app, and rebuild the library for a few days.

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