# Percona Xtrabackup Undo Log Truncation **URL:** \ **Category:** Percona XtraBackup\ **Created:** [November 2, 2022, 8:13am UTC](https://forums.percona.com/t/percona-xtrabackup-undo-log-truncation/18307 "2022-11-02T08:13:57Z")\ **Posts on this page:** 4\ **Page:** 1
**Author:** ![Jyoti\_Rajai](https://sea1.discourse-cdn.com/flex019/user_avatar/forums.percona.com/jyoti_rajai/32/4482_2.png) [@Jyoti\_Rajai](https://forums.percona.com/u/Jyoti_Rajai)\ **Post date:** [November 2, 2022, 8:13am UTC](https://forums.percona.com/t/percona-xtrabackup-undo-log-truncation/18307/1 "2022-11-02T08:13:57Z")
Xtrabackup failed with below error : 2022-11-02T12:41:20.587275+05:30 0 [Note] [MY-012902] [InnoDB] Undo tablespace number 1 was being truncated when mysqld quit. 2022-11-02T12:41:20.587323+05:30 0 [ERROR] [MY-012903] [InnoDB] Cannot recover a truncated undo tablespace in read-only mode 2022-11-02T12:41:20.587351+05:30 0 [ERROR] [MY-011825] [Xtrabackup] xb\_load\_tablespaces() failed with error code 57 Server version: 8.0.28 MySQL Community Server - GPL Xtrabackup Version : 8.0.29 Undo log report mysql\> SELECT \* FROM INFORMATION\_SCHEMA.FILES → WHERE FILE\_TYPE LIKE ‘UNDO LOG’ \G \*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\* 1. row \*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\* FILE\_ID: 4294958516 FILE\_NAME: ./undo\_001 FILE\_TYPE: UNDO LOG TABLESPACE\_NAME: innodb\_undo\_001 TABLE\_CATALOG: TABLE\_SCHEMA: NULL TABLE\_NAME: NULL LOGFILE\_GROUP\_NAME: NULL LOGFILE\_GROUP\_NUMBER: NULL ENGINE: InnoDB FULLTEXT\_KEYS: NULL DELETED\_ROWS: NULL UPDATE\_COUNT: NULL FREE\_EXTENTS: 14 TOTAL\_EXTENTS: 32 EXTENT\_SIZE: 1048576 INITIAL\_SIZE: 16777216 MAXIMUM\_SIZE: NULL AUTOEXTEND\_SIZE: 16777216 CREATION\_TIME: NULL LAST\_UPDATE\_TIME: NULL LAST\_ACCESS\_TIME: NULL RECOVER\_TIME: NULL TRANSACTION\_COUNTER: NULL VERSION: NULL ROW\_FORMAT: NULL TABLE\_ROWS: NULL AVG\_ROW\_LENGTH: NULL DATA\_LENGTH: NULL MAX\_DATA\_LENGTH: NULL INDEX\_LENGTH: NULL DATA\_FREE: 18874368 CREATE\_TIME: NULL UPDATE\_TIME: NULL CHECK\_TIME: NULL CHECKSUM: NULL STATUS: NORMAL EXTRA: NULL \*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\* 2. row \*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\* FILE\_ID: 4294956610 FILE\_NAME: ./undo\_002 FILE\_TYPE: UNDO LOG TABLESPACE\_NAME: innodb\_undo\_002 TABLE\_CATALOG: TABLE\_SCHEMA: NULL TABLE\_NAME: NULL LOGFILE\_GROUP\_NAME: NULL LOGFILE\_GROUP\_NUMBER: NULL ENGINE: InnoDB FULLTEXT\_KEYS: NULL DELETED\_ROWS: NULL UPDATE\_COUNT: NULL FREE\_EXTENTS: 4 TOTAL\_EXTENTS: 32 EXTENT\_SIZE: 1048576 INITIAL\_SIZE: 16777216 MAXIMUM\_SIZE: NULL AUTOEXTEND\_SIZE: 16777216 CREATION\_TIME: NULL LAST\_UPDATE\_TIME: NULL LAST\_ACCESS\_TIME: NULL RECOVER\_TIME: NULL TRANSACTION\_COUNTER: NULL VERSION: NULL ROW\_FORMAT: NULL TABLE\_ROWS: NULL AVG\_ROW\_LENGTH: NULL DATA\_LENGTH: NULL MAX\_DATA\_LENGTH: NULL INDEX\_LENGTH: NULL DATA\_FREE: 20971520 CREATE\_TIME: NULL UPDATE\_TIME: NULL CHECK\_TIME: NULL CHECKSUM: NULL STATUS: NORMAL EXTRA: NULL 2 rows in set (0.35 sec) **We have also tried manually purge undo log:** set global innodb\_undo\_log\_truncate=off set global innodb\_max\_undo\_log\_size=50M set global innodb\_undo\_log\_truncate=ON **Before :** -rw-r----- 1 mysql mysql 704M Nov 2 11:56 undo\_002 -rw-r----- 1 mysql mysql 368M Nov 2 11:56 undo\_001 **After :** -rw-r----- 1 mysql mysql 16K Nov 2 12:10 undo\_2\_trunc.log -rw-r----- 1 mysql mysql 16M Nov 2 12:10 undo\_002 -rw-r----- 1 mysql mysql 16K Nov 2 12:10 undo\_1\_trunc.log -rw-r----- 1 mysql mysql 16M Nov 2 12:10 undo\_001 No Luck still backup failed. This is production server we will hardly get downtime for Instance Restart. Any help would be highly appreciated. Regards, Jyoti Rajai ---
**Author:** ![satya.bodapati](https://sea1.discourse-cdn.com/flex019/user_avatar/forums.percona.com/satya.bodapati/32/1322_2.png) [@satya.bodapati](https://forums.percona.com/u/satya.bodapati)\ **Post date:** [November 2, 2022, 10:46am UTC](https://forums.percona.com/t/percona-xtrabackup-undo-log-truncation/18307/2 "2022-11-02T10:46:46Z")
Hi Jyothi, It looks like you are facing [[PXB-2702] Backup fails when undo truncation log is present - Percona JIRA](https://jira.percona.com/browse/PXB-2702) MySQL server is supposed to remove the undo\*\_trunc.log after resuming from crash. For some reason, it leaves this file (orphan). This confuses backup. We will be fixing in the upcoming release of PXB 8.0.30 As a workaround, you can try to rename them the undo\__trunc.log files in server data directory to undo_\_trunc.log.backup(or any other extension except .log) ---
**Author:** ![satya.bodapati](https://sea1.discourse-cdn.com/flex019/user_avatar/forums.percona.com/satya.bodapati/32/1322_2.png) [@satya.bodapati](https://forums.percona.com/u/satya.bodapati)\ **Post date:** [November 9, 2022, 11:00am UTC](https://forums.percona.com/t/percona-xtrabackup-undo-log-truncation/18307/3 "2022-11-09T11:00:41Z")
@Jyoti_Rajai I hope my suggestion worked for you. If not, please let us know ---
**Author:** ![Jyoti\_Rajai](https://sea1.discourse-cdn.com/flex019/user_avatar/forums.percona.com/jyoti_rajai/32/4482_2.png) [@Jyoti\_Rajai](https://forums.percona.com/u/Jyoti_Rajai)\ **Post date:** [November 17, 2022, 7:02am UTC](https://forums.percona.com/t/percona-xtrabackup-undo-log-truncation/18307/4 "2022-11-17T07:02:08Z")
YEs it did helped. Thanks a lot.