【MySQL】xtrabackup: Fatal error: cannot find ./xtrabackup_logfile

朋友微信留言，说他使用xtrabackup备份的数据除了问题，不能还原了。让他把日志发来看看：

# /usr/bin/xtrabackup --defaults-file=/etc/my.cnf --prepare --target-dir=/tmp/a
xtrabackup: recognized server arguments: 
xtrabackup: recognized client arguments: --prepare=1 --target-dir=/tmp/a 
/usr/bin/xtrabackup version 2.4.26 based on MySQL server 5.7.31 Linux (x86_64) (revision id: 19de43b)
xtrabackup: cd to /tmp/a/
xtrabackup: This target seems to be not prepared yet.
InnoDB: Number of pools: 1
InnoDB: Operating system error number 2 in a file operation.
InnoDB: The error means the system cannot find the path specified.
xtrabackup: Warning: cannot open ./xtrabackup_logfile. will try to find.
InnoDB: Operating system error number 2 in a file operation.
InnoDB: The error means the system cannot find the path specified.
  xtrabackup: Fatal error: cannot find ./xtrabackup_logfile.
xtrabackup: Error: xtrabackup_init_temp_log() failed.

　　

从这里看是，找不到备份文件xtrabackup_logfile。
让后让他进入备份路径target-dir看一下，发现的确是没有文件xtrabackup_logfile，但是有文件xtrabackup_logfile.qp
很明显，备份时使用了压缩选项。而在prepare之前，没有做解压缩操作。

解压一下即可：

/usr/bin/xtrabackup --decompress --parallel=4 --target-dir=/tmp/a