PR4100 32TB Raid-5 with Plex Media Server Best Options to Upgrade Drives

I have a PR4100 32TB configured with four 8TB drives configured for RAID-5, which runs PLEX Media Server (PMS) software with lots of movies and TV series that I’ve collected. I currently have approximately 5TB left of storage available, and was thinking of doing an upgrade to 4 larger drives. I would like recommendations on the best method for upgrading my PMS. The OS5 software and PMS is up-to-date. Also, I would like to know if I can still access my PMS while the upgrade is in progress. Thank you very much in advance for your recommendations and prompt response.

@Felix-Cat

You have a Pro My Cloud with four bays. You need to post in the sub-forum for your device.
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You want a drive rated for NAS service (which is a 24/7/365 application)

The only drives to really avoid are WD Red series. Stick with Red Plus or Red Pro. The difference between Red Plus and Red Pro is, I believe, drive platter speed. In a NAS unit, I think you are limited by the network speed, not the drive speed, so I don’t think the drive speed matters.

I have read that WD S.M.A.R.T. marks an error for any drive over x (x=2?) years old. . . I may be wrong on that. You might want to confirm that point (and I am not sure if that flag is from the drive, or from the NAS).

The only Real key is to avoid any drive using SMR. You want CMR drives (WD Red= SMR for
smaller drives, Red Plus = CMR all sizes). If you can’t find this clearly written, the drive is SMR.

Manufacturer’s claim SMR is fine for NAS service. Anyone who worked with SMR drives. . .have not really found them fit for any service, except maybe for Archive applications where you NEVER use the drive EVER.