udevd-work error and Buffer I/O error are logged in the /var/log/messages before backups of System Recovery Linux Edition complete.

https://www.veritas.com/support/en_US/article.100013912

 

Problem

udevd-work error and Buffer I/O error or only udevd-work error are logged in the /var/log/messages before backups of System Recovery Linux Edition complete.
 

Error Message

udevd-work[PID]: error opening ATTR{/sys/devices/virtual/block/snapX_X/queue/iosched/slice_idle} for writing: No such file or directory
udevd-work[PID]: error opening ATTR{/sys/devices/virtual/block/snapX_X/queue/iosched/quantum} for writing: No such file or directory

OR

kernel: Buffer I/O error on device snapX_X, logical block X
udevd-work[PID]: error opening ATTR{/sys/devices/virtual/block/snapX_X/queue/iosched/slice_idle} for writing: No such file or directory
udevd-work[PID]: error opening ATTR{/sys/devices/virtual/block/snapX_X/queue/iosched/quantum} for writing: No such file or directory

Cause

- buffer I/O error

snapX_X is unsnpaped while '/sbin/blkid -o udev -p /dev/snapX_X' is running.

The blkid is executed by udev rulues file:60-persistent-storage.rules.

 

- udevd-work error

After snapX_X is unsnpaped, the following files are updated by udev rulues file:80-iosched.rules.

 

/sys/devices/virtual/block/snapX_x/queue/iosched/slice_idle
/sys/devices/virtual/block/snap8_1/queue/iosched/quantum 

Solution

• Ignore these messages as these do not cause harms for backed up recovery point files.
  
  OR
   
• Override the rules by the following steps.
  
  Warning: Technical Support for overriding udev rules is limited to the use and troubleshooting of System Recovery Linux Edition. Support is not offered for overriding udev rules operations outside the functionality of Veritas System Recovery Linux Edition. The information below is provided "as is" and questions about udev rules or the process used to override udev rules should be directed to OS vendor.
  
  1. Copy /lib/udev/rules.d/60-persistent-storage.rules to /etc/udev/rules.d/60-persistent-storage.rules
  
  2. Override 60-persistent-storage.rules with edtting a line in /etc/udev/rules.d/60-persistent-storage.rules as follows
  
     * Before change
     # skip rules for inappropriate block devices
     KERNEL=="fd*|mtd*|nbd*|gnbd*|btibm*|dm-*|md*", GOTO="persistent_storage_end"
  
     * After chagne
     # skip rules for inappropriate block devices
     KERNEL=="fd*|mtd*|nbd*|gnbd*|btibm*|dm-*|md*|snap*", GOTO="persistent_storage_end"
  
  3. Copy /lib/udev/rules.d/80-iosched.rules to /etc/udev/rules.d/80-iosched.rules
  
  4. Override 80-iosched.rules with edtting a line in /etc/udev/rules.d/80-iosched.rules
  
     * Before change
     KERNEL=="dm-*", GOTO="end_iosched"
  
     * After chagne
     KERNEL=="dm-*|snap*", GOTO="end_iosched"
  
  5. Reload udev rules: reboot or running "udevadm control --reload-rules"

 

Applies To

Red Hat Enterprise Linux (RHEL) 6.x