Dell server powerEdge R730 failed virtual disk

I would examine the systems logs and/or iDRAC. 

Are all drives present and healthy?

You didn’t provide a lot of information. 

Dear

@Tusj

​kindly find the video and pictures to have information.

if required any information's. tell me please

Dear @DELL-Marco B​ 

thanks for your response.

already i reset the disk and restart the server, and the 3 disk showed same statues (removed).

and i don't have backup.

what did you mean about backplane to the controller?   

regards 

Did two of the failed disks belong to the same RAID5 array? If so, your data is gone I’d think. 

Did you not get any notice when the first disk failed?

The backplane is the board connected to your hotswap drive cages. 
If you follow the SAS cables from the controller, they’re plugged into the backplane (or expander). 

Dear

@Tusj​ 

no , i don't get any notice for failed. 

may i have best scenario to escape from this problem?, (without lose any data)

and how i can avoid like this problem in future ?  

@DELL-Marco B​ 

Good morning

as you see in log video, i don't remove any hard disk, 

 what did you think about it? why The hard disks showed removed ?

@BINNASSER​ The ancient saying in server administration: RAID is not backup. 

One important step in configuring servers is setting up alerts.

These machines are built with a lot of monitoring inside, but they’re pointless if a human isn’t actually getting these alerts, and reacting to them.