External USB drive to preclear before installing internal

[insaneavi]

Hello all,

 

I have a quick question. I just got 4 10TB best buy easy store drives (on sale for 180 each BTW https://www.bestbuy.com/site/wd-easystore-10tb-external-usb-3-0-hard-drive-with-32gb-easystore-usb-flash-drive-black/6290669.p?skuId=6290669)

 

Currently i have Norco 20 bay, which is maxed out, I wanted to know if i could connect 1-2 via USB and preclear them, this way i can save time on adding them to the array after shucking them. 

 

Also any thoughts on if prelcear via USB or using internal slot is any different (my thought is no as the same secotrs get read, then written and then read again regardless of the interface?)

[John_M]

I personally wouldn't preclear disks inside their USB cases for three reasons:

• They will get hot as there is hardly any airflow and preclear works them hard.
• Many USB to SATA bridge chips don't pass the full SMART data.
• Some Western Digital external drives use an encrypting USB to SATA bridge. So whatever you write to them via the bridge can only be read via the same route - instead of writing zeros you're writing junk to the disks.

So it's better to shuck them first.

[whipdancer]

I always preclear external drives before I shuck them.  Then I preclear them again.

The issue is speed for me. I don't get remotely the same speeds via usb as I would internally.  As long as I'm not in a rush, that is fine. I run preclear 2x still in the case. Shuck it, run preclear 2 more times. My thinking is that making it through 2 cycles in the case means the drive is likely to be ok. Running it twice more is just for peace of mind that I've torture tested the drive and if it fails prematurely, there really wasn't anything else I could have done to know ahead of time.

I've had exactly 3 drives fail during this process and I was able to return them for exchange.

Just my $.02.

[insaneavi]

Thanks, I tried the USB and it wouldn't even detect them. I decided remove my hot spare and my cache drive, and then the preclrear on the 10tb's, in about 42 hours hopefully they will be good.