I checked, and only the Seagate BarraCuda seems to be SMR. As I understand it, CMR drives are better performance-wise if they are on 24/7 than SMR drives. Would this mean that all the other drives would be limited by the performance of this slower drive? If so, how much of a performance decrease would I see? If this is the only drawback, would it be a good idea to still include this hard drive in the pool until it breaks so that I get my usage out of it? (I say "only" becuase I consider my usage for this build to be relatively light. Is this a right assumption to make?)
One last thing, I didn't see anything in the hardware guide about wether drives are SRM or CRM. Is this because the guide is meant to be more basic or because there isn't a huge differance in performance between the 2 types?
Quoting the
List of known SMR drives:
SMR has worse sustained write performance than CMR, which can cause severe issues during resilver or other write-intensive operations, up to and including failure of that resilver.
and
As a rule of thumb, avoid SMR drives [...] and you know the drive will function for ZFS during resilver.
CMR are the standard because they are safer for your system, they don't have a cache that can create a bottleneck.
I looked around the forums and saw that some people where reporting problems that were apperantly eventually fixed when they added more RAM to their system. Most of them were runnning systems with more than half a dozen drives. Is this an immedeate concern that could impact the functionality of my build, or is the concern more for the upgradability of the system, or is it just that this is the current recommendation for the minimmum RAM of TrueNAS Core?
The minimum requirements are 16GB.
Look at the download page.
Basically the more RAM you have the happier ZFS is, generally you have the "1GB per TB of space" rule.
I understand the risk of running RAIDZ1, but I dont want to make a full jump to having more than 3 drives which would significantly drive up the cost of this project, both in buying the additional drives, and also since the chance for a drive to fail would increase if I were to add more drives. Also, just for refrence, I have been storing all of my backups and photos across a handful of hard drives, so having any level of redundancy is a big step for me. As for the possibility of running 2 mirrored drives and keeping one as a hot spare, for the purposes of this build I need something > 8tb since I already have close to ~7TB of files and backups. (I heard that having a pool anywhere close to full capacity will sibstantially decrease performance in the ZFS filesystem)
Yes, having a pool over the 80% of capacity will dramatically reduce its performance (generally the closer you get to 90% the slowest it becomes).
You should build your pool with future needs in mind. If you already need 8TB of space, in 3-5 years it is generally safe to imagine you will need double of that: you should build a pool with 16GB of total space.
Now, if you absolutely must use the drives you have posted about (including the SMR one) and also must absolutely use RAIDZ1 becauswe you need more than 8TB of space you can do it, but do know that you risk losing all your data during resilvering after one of your drives die.
You need either another 8TB drive to use for 2 pairs of mirrors, or at least two big (two numbers) TB drives for a single mirror.
This is my informed opinion, you are free to do as you think is best for your interests.
Maybe others can offer you a better solution.
