Asustor Xpanstor 4 AS5004U, 4 Bay Expansion Unit USB 3.1 Gen 2 Type C NAS Storage Capacity Expander

I got this as an expansion addition to my Asustor Lockerstor AS6706T (6 bay, 4 occupied, 2 left for spare install.) So far it works pretty well!!! This model is the newest one that Asustor currently offers at the time of this review. The only thing I didn't initially like is the styling...the front cover panel is an angular magnetic snap on panel which really doesn't match the styling of the main unit AS6706T. Other than that the performance seems quite good as it interfaces with the main unit via a USB 3+ connection. I have it configured as BTRFS RAID 5 format which allows 1 disk failure before replacement and rebuild and also allows snapshots which if a file gets deleted I can revert to an earlier date version for recovery. I'm trying to mostly use this volume as a zipped files directory backup for somewhat archival purposes--fingers crossed it will do what I need it to do!!! My main unit I have WD NAS REDs and this unit I have WD Desktop Blues--trying to separate/segregate the drive types per box so I can see how each performs. So far I am able to direct stream with PlexServer/PlexAmp with no issues other than slow network connections. Just a note that setup was decently easy using the ADM Software provided through the Asustor NAS management web portal.

Easy to use

The whole point of an expansion unit for a NAS is to provide extra drive bays so that you can have more storage available, but it is only possible to create storage volumes *within* a single unit - either the NAS or the expansion - so you will have separate mounts on your network. You cannot combine the storage between the host NAS and the expansion in any meaningful way.RAID6 is offered by Asustor but essentially worthless as it requires 2 drives out of 4 for parity, and adding these expansion units just means a second(/third/fourth) RAID6 volume wasting half of the space, so if you read the “up to 16 bays” advertising and actually expected to use up to 16 drives as a single volume/mount point, you’ll be disappointed.For the same price as this expansion, you can buy an actual 4-bay NAS (e,g. AS3304T) which will have its own processor/memory/RAID engine and gigabit+ networking, and you will only have the same limitation. It’s not even an independent USB DAS for connection to a computer if the host NAS fails.DO NOT WASTE YOUR MONEY!

Impressive DAS for the Austor NAS. This NAS treats it as an extension of the existing system and it is super easy to setup and administer. I set mine up with 4 12TB drives in Raid 6 configuration and it has been super solid.

This DAS/NAS expansion looks good on paper, but Asustor has some serious quality control issues. The included USB C cable did not work, and I was unable to reach above 40MB/s write speeds with any other USB C cable I had in the house, but I could at least confirm my unit worked. When I placed my unit on a level surface (yes, I measured it with an actual level) only three of the four feet would touch the ground. I knew this was going to be trouble given the unit did not sit level and the vibration of four hard drives was amplified due to this and created unbearable noise. This is my first and last Asustor purchase given such an expensive data appliance failed miserably and is easily surpassed in price and or quality from their competitors.