I ran into the same problem with Percona Server 5.1.50-rel11.4-log backed up and restored with xtrabackup.
mysql> set global general_log = 'ON'; ERROR 13 (HY000): Can't get stat of './mysql/general_log.CSV' (Errcode: 2)
The default log destination is FILE, but it does seem like MySQL expects the CSV to be there, as SingerWang mentioned.
I ran into the same problem with Percona Server 5.1.50-rel11.4-log backed up and restored with xtrabackup.
mysql> set global general_log = 'ON'; general_ log.CSV' (Errcode: 2)
ERROR 13 (HY000): Can't get stat of './mysql/
The default log destination is FILE, but it does seem like MySQL expects the CSV to be there, as SingerWang mentioned.