NAS Drive - WD10EFRX-68FYTNO?

[Enquiries]

I purchased my NAS 918+ and also purchased 2 WD10EFRX-68FYTNO drives to create RAID 1 using bays 1 & 2. Strictly wanted to mirror what my hard drive had on my computer in case of failure. Now I am purchasing a new desktop computer and thought I would expand on the storage of my NAS as I would now be backing up two desktop computers. When going to purchase two more of the WD Reds but a larger size than the 1 TB I now see all this info on SMR/CMR. Can I/Should I purchase SMR for the two new drives or MUST I purchase 2 of the CMR to put in to the other 2 bays. Thank you in advance for any assistance.

[ed]

Yes, you should not mix CMR and SMR drives in a RAID5. It would work, but rebuild times would be longer. You can get different capacity drives or use Seagate drives instead. Or alternatively, if you do get an SMR drive maybe create a separate RAID. It works just fine with mirror configuration.I hope this helps.