About xfsaild related errors

What is xfsaild?
blocked log
The xfsaild thread remains in D state
IT/インフラエンジニアの地位とスキル向上のために

What is xfsaild?

xfsaild stands for XFS Active Item List Daemon.

As with ext3 and ext4, XFS is a journaling file system. Its journal log is temporarily stored in log buffer of main memory and finally written to disk.

The state of the log that exists in the log buffer of the main memory and has not yet been written to the disk is called " Active " and it is stored in the list " Active Item List " on the memory.

The process responsible for managing this "Active Item List" is xfsaild.

Reference URL

https://www.kernel.org/doc/Documentation/filesystems/xfs-delayed-logging-design.txt

blocked log

The following logs are frequently seen with xfsaild related errors.

INFO: task xfsaild / dm - 0: 415 blocked for more than 120 seconds.

This is a log reporting that xfsaild was unable to access disk for 120 seconds or more due to disk loading and other reasons.The impact is mixed, but there are cases where it develops into Call Trace.

For Call Trace, please refer to the following.

About Call Trace

The Call Trace, is a stack trace of the ...

The xfsaild thread remains in D state

If the disk load is too high or the disk failure occurs, in some cases the result of "ps" command is as follows.

root 1755 0.0 0.0 0 0? D Nov 19 9: 46 [xfsaild / dm - 2]
root 1767 0.0 0.0 0 0? D Nov 19 9: 44 [xfsaild / dm - 1]
root 1770 0.0 0.0 0 0? D Nov 19 9: 57 [xfsaild / dm - 3]
root 1773 0.0 0.0 0 0? D Nov 16 9: 59 [xfsaild / dm - 0]

D State is one of the process status of general Linux and means "TASK_UNINTERRUPTIBLE".

Process or thread is in sleep mode and is not responding to asynchronous signal process.In other words, kill -9 can not stop the process.