FS Check stuck at 46%

Hello

I got a bunch of alerts the other night and dont know what to do at this point. do i leave it checking the files?

I have XRaid 4GB. Alll drives were upgraded a few years ago.

here is a run down of what happened:

[Sat Mar 18 05:06:03 EDT 2017] Access to the disk on channel (??) is producing I/O errors.  Although the array is still redundant, please replace this drive as soon as possible, as it is likely to fail soon.

[Sat Mar 18 05:06:05 EDT 2017] Access to the disk on channel (??) is producing I/O errors.  Although the array is still redundant, please replace this drive as soon as possible, as it is likely to fail soon.

[Sat Mar 18 05:06:05 EDT 2017] A SATA reset has been performed on one or more of your disks that may have affected the RAID parity integrity.  It is recommended that you perform a RAID volume resync from the RAID Settings tab ( accessible in the Volumes page => Volume tab in  FrontView ).  The resync process will run in the background, and you can continue to use the ReadyNAS in the meantime.

[Sat Mar 18 05:06:06 EDT 2017] Access to the disk on channel (??) is producing I/O errors.  Although the array is still redundant, please replace this drive as soon as possible, as it is likely to fail soon.

[Sat Mar 18 06:13:48 EDT 2017] RAID sync started on volume C.

Next morning it was totally hosed

Powered down via power switch

Disk check ran up to 46% and is frozen there. (power button flashing)

I left it for 24 hours still at 46%

I powered down again last night and it ran to 46% and is still there now.

What is my next step? How long do i leave it running? PLEASE HELP!!

Thank you!