SuperMicro server beeps on startup?

Question

RAID

The situation is as follows, I came to work in the morning - the server beeps. The SuperMicro server itself with hot-replacement of raid disks.
So in order.
On startup it gives the line

FOLLoWING Arrays have Missing or Rebuilding or Failed Member and are degraded <br/>
Array#0 - RAID-5 <br/>
Press [ENTER] to accept the current configuration <br/>
 <br/>
Array# -RAID-5 *** Degraded <br/>
 <br/>
1 Array(s) Found <br/>
 <br/>
BIOS installed Successfully!

Controller: Adaptec 5805 Family Controller
Raid type: 5
Drives: Segate Barracuda ES2 250GB ST3250310NS
Number of drives: 5 pcs.
In the Adaptec utility, you can see the following
1) Array Status DEGRADED
2) Type: Raid 5
What Raid looks like in the Adaptec utility:
1) CN1:DEV00
2) Box00:Slot03
3) Box00:Slot02
4) Box00:Slot01
5) Box00:Slot00
When you enter in this raid, then the line Box00:Slot03 is lit for some reason in gray, all the rest are white.
The server has a Citrix XenServer virtual machine, it hosts 2 Windows servers.
But what is interesting, with the 5th raid, if one disk fails, the system continues to work, and then when Citrix starts, it eventually gives its error that it cannot mount any files.
What are your thoughts on this and how to proceed?

Answer 1

Change the problematic screw, rebuild the RAID.
And all because RAID should not be 5, but 6 - good - there are enough disks.

Answer 2

1) Will the data be saved when rebuilding?
2) Why doesn't Citrix start? although only one disc was released.
Citrix writes something like Inode 404995 has illegal block(s)
Unexpected Inconsistency; Run fsch manually It
asks you to enter the password for root
Because it cannot mount something and goes into reboot

Answer 3

I inserted a new disk into the same slot, but I don’t understand what’s next, if you enter this array, then the new disk is not included in it and it’s not clear how to add it.