migrating from mergerfs thoughts?


Feb 23, 2024
Hi there

I currently have a Dell R720XD with two 6TB hard drives, two 8TB hard drives, one 18TB hard drive, and two 1TB enterprise solid state drives for incoming write caches, on a 10gbe network. They're a mixture of SAS and SATA drives.

On the software side, I'm running Proxmox and my storage server is a debian vm running mergerfs sans parity, as all I've been storing on the array has been re-downloadable media. mergerfs has been great for that, but now that I'm branching out and need a place to store stuff I really really dont wanna lose. Stuff like personal documents, backups, etc. I'm attempting to evaluate using TrueNAS SCALE for my use case.

I'm a software engineer, I know my way around linux systems, been using linux since the late nineties, but I'm a ZFS newbie. Does ZFS support this level of heterogeniality? Even if it does, does it make sense to use this set of drives in the context of TrueNAS/ZFS?


May 17, 2014
The equivalent of RAID-5/6 for ZFS is RAID-Z1/2 which requires similar sized disks. Any extra disk space in a RAID-Zx group because of mismatched sizes is temporarily ignored. You can later swap out the smaller disks with larger to "grow" the RAID-Zx group, (ZFS RAID-Zx groups are called vDevs, Virtual Devices).

ZFS also supports Mirrors, which individual vDevs can be different sizes, (vDev 1 could be a pair of 6TB disks, while vDev 2 could be a pair of 8TB disks). But, with larger disks, more redundancy is suggested...

I would recommend reading up on both what TrueNAS & ZFS are and can do, as they are not the perfect tools for all uses. See the top of the forum page for "Resources". Their are dozens, though many won't apply for you, lots are appropriate for new users. For example;

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