Xtrabackup: Error writing file '<unopen fd>' (os errno 5 - input/output error)

hello, Please tell me what is the cause of this problem…



xtrabackup: Error writing file ‘’ (os errno 5 - input/output error)
xtrabackup:Error:xtrabackup_copy_datafile() failed.
xtrabackup:Error:failed to copy datafile.

ulimit -n

Welcome to the Percona community @bili,

To start with I’d consider using exact version for xtrabackup and mysql.
Then, I assume here that the ulimit -n 1000000 is for the user you run xtrabackup with. If not, I’d make sure of that.
Now, can you confirm if the command did progress for some time and then failed or was it an immediate failure? I’m trying to figure out if the issue is with the permissions/storage etc which might not let the backup to even start OR is it some limitation that is causing to terminate after it started!

There’s a “similar” issue that was noted here, does it help?


Thanks for answering my question. The command did progress for some time and then failed. It may be a storage issue and high storage usage. I’ll check again. Thanks!