I'm going to wanna run scheduled parity checks once a month as a way to both read all sectors (trigger any lurking pre-fail SMART attributes like pending or realloc) as well as of course making sure parity is sane. I have a couple of questions in relation to it, and in general.
1) My setup is up to 24 internal drives on a single 2400MB/s SAS2 connection due to the backplane's expander having a single SFF-8087 connector. So theoretically all drives have 100MB/s if they are all used at once. I have gigabit network and expect along those lines when reading from a share. Will I suffer hard here during checking? I suppose I could leave ~4 unused for spares etc. which would open up some bandwidth. Opening up hopefully at least 10-20MB/s for high bitrate movies.
2) Do unraid have something like smartd running that can instantly notify me if a bad attribute has been discovered within just minutes? And if I'm vigilant of replacing any such drive, can I expect the array of staying intact - even during sudden power loss? As in, if no drives got bad during the power loss, unraid will be able to fix any parity problems and at least have all other data intact except the file or data that was being written. (yes I got UPS, but wondering either way. I've had old units ironically create power loss themselves when battery goes old).
3) One of the reasons I haven't tried unraid before is the USB drive aspect. So I just wanna ask straight up, is there any scenario where I can loose my array or data on it from a catastrophically defective USB boot drive? Disregarding any human errors I may make myself replacing it. I mean any action it may take itself while booting up erroneously. Simply put, can I risk the array due to a bad boot USB drive? While we all praise the need for backups, this would probably be a deal breaker for me.
My only need for this server is 4 user shares just for backing up and storing documents and videos, as well as the plex media. While having a single VM run Windows Server 2019 on SSD cache pool (I guess this is the common way?) of 2-3 SSDs. I got like 5-6 laying around. That single VM img or qcow2 (do unraid support qcow2?) will serve all and any services in that VM, including plex and its metadata (trying to keep things simple). The only load on the array will be reading and writing backup files and media. It won't host games, databases, VMs or anything intensive. I just need storage and that single VM to be stable without hickups or weird freezes (as long as my hardware is OK of course).
I'm on the fence about keeping the stablebit stack of software with all its quirks and limitations, being a filesystem filter (community and support also becoming slower and less active these days) where I'd do pool:cloud realtime duplication. Or roll my own minimal debian solution (it's what I'm most comfortable with of all distros) install with zfs and kvm (minimal gui with xorg and openbox for the comfort of using virt-manager to handle VM) which I've already battle tested just to see what I can expect, so I'm getting comfortable with it. Or go unraid and being able to expand easier, not having to pay up front and plan big 8x raidz2 vdevs at once. Also at the cost of more parity...
Regardless, rclone backups to my gsuite where everything is today (managing it is slow, so I want it local again). Backup is covered, but I rather not download ~60-100TB in the long run unless I really have to, due to loosing ALL data on striped conventional raids (the reason I'm not going with hardware raid, even though I like adaptec). With unraid I'm most worried about loosing just SOME data, but not knowing exactly WHAT I've lost (would seriously strain my OCD). But a simple rclone sync operation should fix that. Another thing that's dodgy with stablebit, unless they've fixed it recently.
This ended up being a wall of text... Sorry. I just got a lot on my mind. Tend to get obsessed when faced with a challenge/problem/issue.
This community is mega responsive, and I love you all for it. There's a huge chance I'll buy a pro license before the weekend knocks.