So, I struggled with 2 x 8TB HDD’s as stripe in truenas as zfs managed through a sata6 UGT-ST644R-stripe not set by UGT-ST644R but by truenas latest v24, truenas kept reporting I/O errors on one hdd copying through SMB to truenas dataset of the pool, so i exported/deleted the pool many times frustrated, finally had it, don’t know what was going on, 2 nearly new 8TB hdd’s, 1 brand new, second 27 power on counts, I decided to have the UGT-ST644R manage the stripe, raid0 stripe the 2 in 64k, added the “1” as truenas sees it, because the raid card creates the 2 > 1 before truenas sees it, created the smb pool/dataset, no more I/O errors.
This was the only way I could figure to fix the problem.
And it seems logical to do so for stripe 2xhdd’s/ssd’s, because, if one error happens in truenas while truenas handles 2 x stripe pool, the pool is gone/un-healthy/unusable. But as truenas handles the “1” as a pool, truenas can’t say, I/O erros on one of the drives etc. Also, it just seems logical to have any raid card handle raid period, because one hiccup from truenas os, even with zraid3 with 5 hdd’s, one I/O error, now you have down time to
find/figure whats up, just raid card them, set it up and be done.
Did you re-flash the UGT-ST644R to enable RAID on it? If not, it might not have been in IT mode (or pass through mode) before, which might explain the I/O errors.
My personal advice from personal experience; I’d never give TrueNAS disks which it doesn’t control since many functions rely on direct disk access. Also, striping 2 disks is inherently risky since you lose everything if one disk fails. But I have to assume that you’re aware of that. Also, keep in mind that if your RAID Controller fails, you most likely need the exact same make and model to even have a chance of recovering your RAID. Again: This is all in my experience and humble opinion.
Not sure about that being the I/O problem, seems to me, truenas os mis-handled something, just one small hiccup as I experienced, bam. yea,I am aware of raid0, just from one small truenas OS hicup > a stripex2 or even zraid with 5 disks, one hiccup from the os, its downtime and troubleshooting.
If I could, I’d raid 1+0 4-6 HDD’s and prob use fedora or something as NAS. I am not entirely sure about truenas yet, even with zraid1-3. Seems to me, just that one hiccup from the OS’s, your pool is scrapped.
