RND4000 v3 disk replacement does not work

Hello community,

i have a very strange problem. I hope you can help me. I have a rnd4000 v3 with 4 seagate barracuda (st1000dl002) 1TB HDD´s. On of them (slot 2) crashed last week. So i bought a western digital RED WD10EFRX and replaced the barracuda. In the first step i did a shutdown of the nas (i know the nas also provides hot swap) and replaced the barracude. After the reboot the nas began to sync the disks. The strange thing of this situation was that the sync process took more than 24 hours and came not to the end. While the sync was proceeding I can´t get access to my shares and raidar was not able to find the nas in the network. After 24 hours i lost my patience and i removed the western digital disk. After that i was able to access my shares and files again. I also was able to find the nas in the network.

My second try was to put the disk into the nas while the nas was running.So i use the hot swap feature :-)

The result was that the nas tried to start the initialization of the disk but this also came not to the end. And again i didn´t have access to my shares and the raidar was not able to find the nas in this time. Since i have removed the disk again i have fully access to my shares.

Does anybody have an idea what to do?