# Unmatched LSN **URL:** \ **Category:** Percona XtraBackup\ **Created:** [May 26, 2011, 12:54pm UTC](https://forums.percona.com/t/unmatched-lsn/2149 "2011-05-26T12:54:17Z")\ **Posts on this page:** 3\ **Page:** 1
**Author:** ![annash](https://avatars.discourse-cdn.com/v4/letter/a/e68b1a/32.png) [@annash](https://forums.percona.com/u/annash)\ **Post date:** [May 26, 2011, 12:54pm UTC](https://forums.percona.com/t/unmatched-lsn/2149/1 "2011-05-26T12:54:17Z")
Hello, That is a quote from your documentation ( [http://www.percona.com/docs/wiki/percona-xtrabackup:xtraback](http://www.percona.com/docs/wiki/percona-xtrabackup:xtraback) up:incremental#preparing\_the\_backups): “The log sequence number should match the to\_lsn of the base backup, which you saw previously.” But it never does for me. $ xtrabackup\_55 --backup --datadir=/my\_dir/ --target-dir=/data/backups/base --defaults-file=/my\_dir/data/my.cnf … xtrabackup: Transaction log of lsn (1172058792) to (1172058792) was copied. $ /xtrabackup\_55 --backup --target-dir=/data/backups/inc1 --incremental-basedir=/data/backups/base --datadir=/my\_dir/ --defaults-file=/my\_dir/data/my.cnf … xtrabackup: Transaction log of lsn (1172059221) to (1172059221) was copied. $ xtrabackup\_55 --prepare --apply-log-only --target-dir=/data/backups/base --defaults-file=/my\_dir/data/my.cnf … 110526 14:15:38 InnoDB: Shutdown completed; log sequence number 1172060122 Does it mean that my backup is corrupted? ---
**Author:** ![xaprb](https://avatars.discourse-cdn.com/v4/letter/x/49beb7/32.png) [@xaprb](https://forums.percona.com/u/xaprb)\ **Post date:** [May 30, 2011, 5:26am UTC](https://forums.percona.com/t/unmatched-lsn/2149/2 "2011-05-30T05:26:20Z")
You are looking at the documentation for the “prepare” functionality. It does not apply to the “backup” stage of the process, which is the source of the output you pasted. ---
**Author:** ![annash](https://avatars.discourse-cdn.com/v4/letter/a/e68b1a/32.png) [@annash](https://forums.percona.com/u/annash)\ **Post date:** [May 31, 2011, 4:13pm UTC](https://forums.percona.com/t/unmatched-lsn/2149/3 "2011-05-31T16:13:02Z")
Right, that’s the “prepare” in my output. Where I should look for “1172060122” to compare with? $ xtrabackup\_55 --prepare --apply-log-only --target-dir=/data/backups/base --defaults-file=/my\_dir/data/my.cnf … 110526 14:15:38 InnoDB: Shutdown completed; log sequence number 1172060122