AS6602T - FileExplorer hangs reading from USB drive

[tenly]

I just got this unit a couple of days ago and installed:
- 2x 10TB Seagate IronWolf drives (mirrored)
- 2x 1TB Samsung 970 EvoPlus NVME SSD drives as RW cache

The NAS Volume1 is pretty much empty (no personal data copied to it yet).
I did install a couple of apps from ADM (docker,portainer-ce, sqlserver, nextcloud and syslog server) but there is nothing important in them - so if I need to wipe everything and start over - it's not a big deal.

I have a USB 3.0 dual drive dock connected to one of the rear USB ports. There's a 3.5" 6TB Western Digital Red drive in the dock.
The 6TB drive contains 700,000 photos and videos that I want to transfer to the NAS.

The photos and videos are currently spread across 4 different folders named "photo-library-#" and each photo-library folder has subfolders for years which have subfolders for months which hold the actual files.
(directory structure is /photo-library-#/yyyy/mm/ )

My goal was to move all 4 photo-library folders to the NAS (one at a time) - but when I attempt to copy the top-level folder for "photo-library-1" by right-clicking it and choosing "Copy to...", it lets me specify the destination folder on the NAS, and the "Copy Files" dialog box appears - but it never starts working. I've left it overnight and the progress bar never starts moving.

FileExplorer also hangs when I right click and attempt to view properties of the folder (to get a file count).
The directory structure is not complex or deep - but there could be over 300,000 files in one of these structures (which I thought a NAS would/could handle easily). Is the problem with the number of files? Or with the fact that it's USB? Or is FileExplorer not the best tool to use?

Anyhow - when that failed, I tried to copy the subfolders of "photo-library-1" individually - and it worked for some of them - but when I got to the 2018 folder it hangs again. (I can't even expand the folder to see the 12 subfolders - it hangs at that point too.)

Is there a way to make this work ? Or is there a better/faster/easier way that I can transfer the files from the 6TB drive to my NAS?

For example, could I break my mirror, then install just 1 of the 10TB drives and use the 2nd bay for the 6TB drive, copy the files over (taking USB out of the mix), then remove the 6TB drive, install the 2nd 10TB drive and then re-create the mirror while preserving the data on the 1st 10TB drive? Or does creating the mirror automatically wipe both drives?

Thanks.

[bombonatti]

I just moved to a similar configuration
- NVME with volume1
- Disks RAID1 volume2

I could not use NAS USB to copy files, so I used a computer to send it over network, took longer but I succeeded to complete copies.

Now, I have a different issue, I want to copy/move large files from volume1 (NVME) to volume2 (RAID1 disks) and system hangs during copy.

Do you save same issue in your NAS?

Currently my setup is:
AS6602T - ADM 4.0.0.RN53
volume1 in NVME Crucial P5 Plus (500GB)
volume2 in RAID1 2x 8TB (WD Red / Seagete Ironwolf)

[orion]

I can copy to / from USB devices. But I did not own such big number of files in USB. I guess certain processes are in background for each file. Anyway it must not be a correct way for such a long waiting time. I'll suggest you to send a support ticket to check it: https://support.asustor.com/. They should be able to gather detailed info remotely.