I/O Errors During Operation Using iSCSI on RHEL/Rocky/AlmaLinux

Audience
Public
Content Type
Source Type
Knowledge Base

I/O Errors During Operation Using iSCSI on RHEL/Rocky/AlmaLinux

KB0023067
Environment

iSCSI on RHEL/Rocky/AlmaLinux

Symptoms
  • Buffer I/O error in dmesg
  • Application errors writing to storage
Resolution

Diagnostic Steps:

# Check connection state
iscsiadm -m session -P 3

# Check multipath status
multipathd show paths

# Check for SCSI errors
dmesg | grep -i "scsi\|iscsi" | tail -20

Resolution:

  1. Session lost: 
    # Logout and re-login iSCSI sessions
iscsiadm -m node -U all
iscsiadm -m node -L all
  2. Path degraded: 
    # Check and repair multipath
multipathd show paths
multipathd reconfigure