• May 21, 2024, 10:28:36 PM
  • Welcome, Guest
Please login or register.

Login with username, password and session length
Advanced search  


This Forum Beta is ONLY for registered owners of D-Link products in the USA for which we have created boards at this time.

Author Topic: WARNING: WD20EFAX issue (SMR recording) in RAID 1  (Read 6157 times)


  • Level 1 Member
  • *
  • Posts: 16
WARNING: WD20EFAX issue (SMR recording) in RAID 1
« on: October 13, 2020, 10:49:31 AM »

HI, I would like to make a warning concerning usage of HDDs with SMR recording technology. If you use RAID 1 on your NAS please DO NOT buy and install WD EFAX series HDDs.

Step 1: In my case I replaced one of my old HDDS with a brand new WD20EFRX harddrive without any problems and further issues.
Step 2: I wanted also to replace the second HDD with brand new WE20EFAX drive 4 months ago. I originally required EFRX however they were not on stock. The retail store staff told me that EFAX serie is a new one and replaces old EFRX and I can use them without problem because they are designed for being permanently in used in NAS.

My mistake was that I did not check the EFAX recording techolnology before the purchase. And a month after the purchase I encountered first problems - EFAX drive degraded my RAID 1 array. Since I enabled the automatic rebuild I noticed that a 2 months later when I was copying large files with my photos to NAS. I encountered RAID 1 degradation again with EFAX drive light in orange. A let the DNS-323 perform automatic rebuild again and everything was fine until the next day when I wanted to finish my copying job. RAID 1 degraded due to EFAX drive again (no problem with EFRX).
It forced me to search the issue on google and I discovered that the problem is SMR (Shingled Media Recording) recording technology bein used in EFAX drives. See article https://blocksandfiles.com/2020/04/14/wd-red-nas-drives-shingled-magnetic-recording/. In spite of the fact that SMR recording technology is not suitable for RAID 1 storage as it causes troubles when copying large files.

No problem with older EFRX that uses CMR (Conventional Magnetic Recording) recording.

Finally I made a RMA with my retail store and after 2 weeks negotiations with WD they approved replacing EFAX drive for EFRX drive. :)

So this a warning to all RAID 1 users - take care what recording technology is used in your new drive. For DNS-323 in RAID 1 I definitely CANNOT recommend WD EFAX drives.