If you receive the following messages listed in the example below, it could be related to a RAID Issue. Most of these errors could be found in dmesg or dmesg.2 or sent to you by email notification
If you receive these errors, Please check your RAID Controller and your RAID array.
Before removing a disk drive please verify that you are removing the correct failed disk drive, as removing the incorrect disk drive may break your RAID.
While the RAID array is running in an unstable or degraded condition, unexpected results can occur.
It can lead to filesystem errors and data loss.
It is best practice to fix this issue as soon as possible.
After you fix your RAID:
Please click on the remove button, then let the system run for a bit and
download and send us your system log files for us to check to see if there are any other issues.
Logs are located here
STATUS -> HARDWARE -> Logs.
The “Logical block” or “sectors” in most instances in the examples below will refer to an issue with one or more of the disk drives.
The following are a few examples of error messages that were caused by either a bad disk drive or a problem with the RAID controller.
Example 1
Buffer I/O error on device dm-6, logical block 235528
lost page write due to I/O error on dm-6
sd 1:0:0:0: rejecting I/O to offline device
Example 2 (failed disk drive)
end_request: I/O error, dev sdf, sector 7007993
Buffer I/O error on device dm-3, logical block 3464313
ata6: translated ATA stat/err 0x51/40 to SCSI SK/ASC/ASCQ 0x3/11/04
ata6: status=0x51 { DriveReady SeekComplete Error }
ata6: error=0x40 { UncorrectableError }
ata6: translated ATA stat/err 0x51/40 to SCSI SK/ASC/ASCQ 0x3/11/04
ata6: status=0x51 { DriveReady SeekComplete Error }
sd 5:0:0:0: SCSI error: return code = 0x8000002
sdf: Current: sense key=0x3
ASC=0x11 ASCQ=0x4
Dec 26 14:35:27 nas kernel: end_request: I/O error, dev sdf, sector 7007983
Example 3
Buffer I/O error on device dm-4, logical block 61520
lost page write due to I/O error on dm-4
sd 1:2:0:0: rejecting I/O to offline device
lost page write due to I/O error on dm-4
This example as it turned out was a bad RAID controller.