My Cloud USB HDD Capacity

Will the USB port on a 3TB My Cloud read the full partition on a 3TB My Passport HDD? I have both 2TB and 3TB My Passports. My current router, and no routers I can find, will read the 3TB drive. Router limitations that also seem to apply on USB NAS devices. I am looking at ordering a 3TB My Cloud, but need to make sure it will read/write to the entire 3TB of the My Passport (NFTS) for backup. I see a lot of write-ups on routers, NAS, etc that talk about adding USB drives, but none talk about limitations.



Do not recall anyone mentioning having problems with large (over 3T) USB hard dives on the My Cloud other than the usual USB not recognized issue that plagued some of us that is not related to the USB hard drive size. The user manuals for the My Cloud ( do not appear to list a capacity limit to the USB hard drive size.

Someone asked a similar question over in the EX4 subforum several years ago:

Hi Bennor, Thanks for the reply. I am thinking that since both devices are WD, and the My Cloud manual refers to using My Passport drives, it will work. But my Cisco router says it supports “most” usb drives. It does support my 2TB My Passport, not the 3TB. Has something to do with the router being linux based I believe. I am about to order a My Cloud, but don’t want to get it out here only to find it will not read the drive.

I just did a test and hooked up my 4TB My Book to my WRT-1900AC router. I was then able to map the dive to my windows system. The properties windows showed that the dirve was 4TB.


Hi Rac,

Interesting. I was able to connect a 3TB Seagate Backup Plus to my Linksys E3200, but the 3TB My Passport would not work. Linksys lists some usb drives over 2TB that work, but others do not. Just wish the vendors would prominently post compatibility lists for all products. I am looking at a linksys EA6900 (AC1900), but need to fix my storage first.

Back on subject, I just got a reply from WD support that the My Cloud usb port should handle the My Passport 3TB drive with no problem, I assume other large drives as well, and I just ordered the 4TB My Cloud. Guess I will know in a week or so. I will post the result.

Thanks for the replies

I have a 6TB cloud. I’ve also connected my 4TB that I’ve connected to the My Cloud. It also works.


Good info on both counts RAC, thanks.


Maybe its Filesystem, Fat32/NTFS thats been there all along?