JorgeB

Disk dropped offline and reconnect with a different letter: May 27 16:45:50 FULSERVE kernel: usb 1-6: USB disconnect, device number 3 May 27 16:45:50 FULSERVE kernel: usb 2-6: USB disconnect, device number 2 May 27 16:45:50 FULSERVE kernel: usb 2-6.1: USB disconnect, device number 3 May 27 16:45:50 FULSERVE kernel: sd 0:0:0:0: [sda] Synchronizing SCSI cache May 27 16:45:50 FULSERVE kernel: sd 0:0:0:0: [sda] Synchronize Cache(10) failed: Result: hostbyte=0x01 driverbyte=0x00 May 27 16:45:52 FULSERVE kernel: usb 1-6: new high-speed USB device number 6 using xhci_hcd May 27 16:45:52 FULSERVE kernel: hub 1-6:1.0: USB hub found May 27 16:45:52 FULSERVE kernel: hub 1-6:1.0: 3 ports detected May 27 16:45:52 FULSERVE kernel: usb 2-6: new SuperSpeed Gen 1 USB device number 4 using xhci_hcd May 27 16:45:52 FULSERVE kernel: hub 2-6:1.0: USB hub found May 27 16:45:52 FULSERVE kernel: hub 2-6:1.0: 3 ports detected We really discourage using USB disks as array devices, both for performance and reliability.

No, I expect it to be considerably faster without encryption.

Disk is formatted with type1 protection, if you Google that you'll find how to remove it.

Errors are being logged as actual disk errors, but that's not 100% reliable and the disk looks healthy and passed the extended SMART test, I would suggest replacing/swapping cables/slot with another disk and trying again.

Yes and yes. The other way around, sometimes when a disk gets disable there's some filesystem corruption, usually nothing major and easily fixed with fsck.

User shares always add some overhead, that CPU doesn't support hardware AES so really not a good option to use with encryption, try without and speed should be noticeably faster.

Please post the diagnostics: Tools -> Diagnostics

No, they are flushed to disk after a few seconds (or when the RAM cache is full).

Diags are after rebooting so we can't see what happened, but the disks look healthy, if data looks correct on the emulated disks you can rebuild on top.

That's not data, the larger the disk the more space will be used by XFS metadata, and data never changes during the rebuild, the data you see with the disk emulated before starting to rebuild is the same you'll see after the rebuild completes. There are constant ATA errors with the parity disk, check cables.

Memtest won't show errors with ECC RAM, if you can't find more info on the affected DIMM, just remove one at a time and test for a few days, or disable ECC in the BIOS (if that's an option) and run memtest again.

Start here: https://forums.unraid.net/topic/46802-faq-for-unraid-v6/?do=findComment&comment=819173

Disk is failing and needs to be replaced.

Log is being spammed so we can't see what happened, this might help with that, but the disk looks healthy.

Disk is failing in a big way and needs to be replaced.

Cache disk is still dropping, did you replace both cables, power and SATA?

SAS expander needs a HBA, it won't work on its own, you use one when you need more ports, instead of adding another HBA.

Please post the diagnostics: Tools-> Diagnostics

It doesn't, it assumes it was successful if the kernel doesn't spit out any errors, there should be one if the correction wasn't correctly written, there was recently a curious case also due to a controller problem:

Best bet is to use the appropriate docker or plugin support thread, depending on what preclear version you're using.

You can use the user scripts plugin.

The filesystem errors were caused by disk4 dropping offline, since you already had a disable drive Unraid couldn't correctly emulate both, check cables on disk4, you can still run a filesystem check on both now but it should be mostly fine.

Please use the existing docker support thread, you can find by clicking on the link:

Please post the diagnostics: Tools -> Diagnostics

No, you just need a couple of SAS to SATA forward breakout cables, like this: https://www.amazon.com/Cable-Matters-Internal-SFF-8087-Breakout/dp/B012BPLYJC/ref=sr_1_3?dchild=1&keywords=SAS+to+SATA+forward+breakout+cables&qid=1591524986&sr=8-3