I’m mulling over the idea of migrating from ZFS to Brtfs on DSM (xpenology) for my upcoming NAS upgrade. Curious if folks here have done that kind of jump?
ZFS has been good to me since 2008 / Illumos days; a few times disks die or failure is predicted early enough to take action before a disaster happens but I think I may be getting a bit of “complexity fatigue” for my homelab environment and so I took a spin at xpenology/DSM 7.1 via redpill and experimented by mapping an LSI controller card to the VM in proxmox and everything seems to be working and with an easy management UI which is one primary reason tempting me to the DSM route.
Other than a nice UI my second priority is to add nvme cache to speed up things on my NAS. From my limited testing on ZFS and reading - it seems that special_metadata_vdevs when enabled for also storing small block files would keep only a single copy of small block files on the SSD cache always without tracking “hot” small files to cache in a more smart way.
Synology seems to implement SSD caching differently, in that it seems to keep track of which blocks or files are most often accessed and the SSDs keep a copy of what’s on the slower disk drives, it seems that SSD cache on DSM could die without destroying the entire pool, is this right?
Closing thoughts: setting up a DSM/xpenology VM with an LSI card passthru was a real pain in the ass to figure out but it does seem to work; but future software updates could be painful or risk major downtime if things were to go wrong. I am also unfamiliar with Brtfs filesystem so unknown what kind of jungle I would be going into with DSM… so coming here to ask you guys
So the take of it is “I like the UI” without any real technical reasons and excluding the fact that btrfs is useless in RAID5/6? If you’re only using a mirror sure but again I don’t see how that’s any easier with btrfs…
Basically what ARC does. Additional copy of data that doesn’t contribute to pool capacity as the “real” blocks are kept in redundant data disks. Looks like some BTRFS + bcache setup. I had this on a Tumbleweed install I tested for a couple of weeks and really missed the ARC. I certainly have less writes and traffic with my L2ARC.
If you want something new, use it and tell us about your experiences, especially compared to ZFS.
The cache is the ARC, your main memory. If files are important and recently or frequently used, they get their place there. DRAM >>> NVMe. ARC algorithm is probably the smartest cache I’ve seen that is available for mortals. If you can’t afford memory, use an NVMe as L2ARC. Special vdevs are for storing data, not for caching data.
I agree ZFS is far superior here, if I was focusing on technicals alone it is no contest. I guess I am trying to evaluate the risks of jumping ship towards synology’s brtfs
I honestly don’t know if synology uses pure brtfs or something proprietary to keep my data hostage to their platform but if that’s the case I was hoping someone to chime in here and warn me cuz that would put the brakes on this whole idea.
I’m not as much of a ZFS expert as these other guys, but I moved the other way. From Synology to TrueNAS Core
The only things I miss are
HyperBackup - Great application to have running directly on a NAS
The ease of setting up SMB shared (Which becomes a non-issues when you’ve made a few in TrueNAS and get used to it)
Everything else is better in TrueNAS. I had 2 x NVMe SSD’s for a cache, and it never worked as well as TrueNAS. The problem is that while the SSD’s may be nice and fast, all of the Synology CPU’s are slow as heck! So now writing to disk on TrueNAS wiith metadata cache, RAM caching and L2ARC is faster anyway
The main reason I moved away from Synology was the encryption. The encryption they use is horrible, and slows the entire array down dramatically. Then, add the fact that if you use encryption, you cannot browse the snapshots! You can only restore an entire snapshot and then browse the contents which is just silly
I had a physical Synology as my main NAS and then xpenology as the secondary. When I ditched my DS1817+ I mulled the idea of xpenology as my main NAS, but IMO this is just crazy. Who knows what issues you will run into, and there is no support. Updates are also a dice roll every single time
Honestly, I would stick with TrueNAS, or at least build an all SSD pool for important data to fix your speed concerns
Thanks - Yeah I think I will probably stick with TrueNAS. I may go to CORE instead of SCALE since the later has been very buggy for me in terms of kubernetes.
