# RAID 1 Mirror Error with Two Western Digital 500GB Drives

raid-1

I have Windows 7 Ultimate 64 bit installed on a Western Digital 500GB drive (WD5000BEVT-22ZAT0) that was partitioned automatically by Windows as 100MB System Reserved and 465.66GB drive C.

There is also an unallocated second Western Digital 500GB drive (WD5000BPVT-22HXZT1) that I want to use for RAID 1 to mirror the first drive but I get an error message stating

“ALL DISKS HOLDING EXTENTS FOR A GIVEN VOLUME MUST HAVE THE SAME SECTOR SIZE, AND THE SECTOR SIZE MUST BE VALID.”

I uninstalled Windows patch KB-982018 but I still get the same error message. Could you please let me know how to resolve this?

The problem is that fsutil does not really report everything as some "helpers" and KB articles tell you. I just had that case: Combining a WD-RED 3 TB with an Seagate Barracuda XT 3 TB.

fsutil fsinfo ntfsinfo <drive_letter> showed both as identical 512 bytes per sector. The Sysinternals ntfsinfo does the same. But then I used smartctl.exe -a /dev/sda from smartmontools (get it from here: https://sourceforge.net/projects/smartmontools/files/smartmontools/ ). And THAT one finally showed the real reason, which Windows does not show...

For the WD-RED WD30EFRX-68AX9N0, smartctl -a /dev/sda says:

Sector Sizes:     512 bytes logical, 4096 bytes physical


For the Seagate ST33000651AS, smartctl -a /dev/sdb says:

Sector Sizes:     512 bytes logical, 512 bytes physical


So for everyone having that problem and not knowing why Windows refuses to mirror even if fsutil confirms the same "sector size", use smartctl to see the REAL stuff.