#!/bin/sh ### # Set SCSI and SATA SCT error timeout. # # SPDX-License-Identifier: CC0-1.0 ### ### # Description # # Configures SCTERC timeout for all disks, setting it to 7 seconds (70 # deciseconds) for improved error handling. If SCTERC is unsupported, # then Linux I/O timeout and the SCSI error handler (EH) timeouts are # increased. # # SCTERC (SCT Error Recovery Control) allows the disk to limit its # internal recovery time, ensuring that it returns an error promptly if # the operation cannot be completed, for example due to a bad sector. # This prevents the SCSI layer from triggering high-level resets (e.g., # LUN, bus, or host resets) that could lead to data loss or filesystem # corruption. If SCTERC is not supported, setting a long "timeout" # helps prevent premature EH invocation. # # In Linux, the "timeout" value is how long the kernel waits for an # individual I/O command to complete before declaring it as failed and # invoking the SCSI Error Handler (EH). Once EH takes over, its # behaviour is governed by the driver implementation. The "eh_timeout" # parameter defines how long the EH is allowed to try recovery # operations before escalating further or offlining the device. # # It is not uncommon to see I/O on normal HDDs taking more than # 30 seconds, the Linux default. To accommodate this, the script sets # the default "timeout" to 60 seconds for devices with SCTERC support. # For devices without SCTERC, the fallback timeout is set to 300 seconds. # # Some SMR (Shingled Magnetic Recording) type HDDs are especially # prone to trigger Linux I/O timeouts, as their internal garbage # collection can take several minutes to complete. You may need to # increase the "sct_device_timeout" and "fallback_device_timeout" for # such devices. # # See the Linux documentation for SCSI error handling at: # https://www.kernel.org/doc/Documentation/scsi/scsi_eh.rst ### scterc_value=70 # SCTERC value in deciseconds (7 seconds) sct_device_timeout=60 # 60s for devices with SCTERC support sct_eh_recovery_timeout=10 # 10s for EH recovery with SCTERC fallback_device_timeout=300 # 300s for devices without SCTERC fallback_eh_recovery_timeout=30 # 30s for EH recovery without SCTERC # Print header printf "%-10s %-40s %-30s\n" "Device" "Model" "Status" echo "------------------------------------------------------------------" # Iterate over /dev/sd[a-z] to target standard SCSI/SATA devices. If you # need to include other block devices (e.g., virtio disks: /dev/vd[a-z], # Xen disks: /dev/xvd[a-z]), adjust the glob pattern accordingly. For # systems with more than 26 SCSI devices, add additional patterns, such # as: # for i in /dev/sd[a-z] /dev/sda[a-z] ; do for i in /dev/sd[a-z] ; do device=$(basename "$i") # Attempt to set the SCTERC timeout to 7 seconds output=$(smartctl -l scterc,$scterc_value,$scterc_value "$i" 2>&1) # Get the device model model=$(smartctl -i "$i" | grep -E "Device Model|Product:" | awk -F: '{print $2}' | xargs) # Check the output for "SCT Commands not supported" if echo "$output" | grep -q "SCT Commands not supported" ; then status="No SCTERC support, using fallback" echo $fallback_device_timeout > "/sys/block/${device}/device/timeout" echo $fallback_eh_recovery_timeout > "/sys/block/${device}/device/eh_timeout" else status="SCTERC set ok" echo $sct_device_timeout > "/sys/block/${device}/device/timeout" echo $sct_eh_recovery_timeout > "/sys/block/${device}/device/eh_timeout" fi # Print the results printf "%-10s %-40s %-30s\n" "$i" "$model" "$status" done