# Log block checksum mismatch

**URL:** <https://forums.percona.com/t/log-block-checksum-mismatch/17313>\
**Category:** Percona XtraBackup\
**Created:** [September 5, 2022, 1:34pm UTC](https://forums.percona.com/t/log-block-checksum-mismatch/17313 "2022-09-05T13:34:17Z")\
**Posts on this page:** 4\
**Page:** 1

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**Author:** ![larryschul](https://avatars.discourse-cdn.com/v4/letter/l/eada6e/32.png) [@larryschul](https://forums.percona.com/u/larryschul)\
**Post date:** [September 5, 2022, 1:34pm UTC](https://forums.percona.com/t/log-block-checksum-mismatch/17313/1 "2022-09-05T13:34:18Z")

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Hello

i am running mysql8 (mysql Ver 8.0.26 for Linux on x86\_64 (Source distribution))  
running on Oracle Linux 8  
xtrabackup version 8.0.28-20 based on MySQL server 8.0.28 Linux (x86\_64) (revision id: 4cc3081873d)

i have been running xtrabackups for a while now without a problem… but now i am seeing this;

2022-09-05T12:44:39.634369-00:00 1 [Warning] [MY-011825] [Xtrabackup] Log block checksum mismatch (block no 0 at lsn 9294482931712): expected 0, calculated checksum 3965168067  
2022-09-05T12:44:39.634413-00:00 1 [Warning] [MY-011825] [Xtrabackup] this is possible when the log block has not been fully written by the server, will retry later.

was very weird… yesterday i saw that for a few hours… also had an explain plan based on a select statement running… the minute that finished… a few minutes later, so did the back… i dont know if the explain plan was somehow causing the problem (i cant think of a reason as to why)… or if something else was…

i am not positive what info would be needed to help with this… so i figured i would start with this… and see where it goes…

thanks in advance for any help…

larry

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**Author:** ![Michael\_Coburn](https://sea1.discourse-cdn.com/flex019/user_avatar/forums.percona.com/michael_coburn/32/18_2.png) [@Michael\_Coburn](https://forums.percona.com/u/Michael_Coburn)\
**Post date:** [September 20, 2022, 8:19pm UTC](https://forums.percona.com/t/log-block-checksum-mismatch/17313/2 "2022-09-20T20:19:49Z")

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Hello @larryschul

Did your backup ever successfully complete? Have you seen the error since?

EXPLAIN can actually execute a query against the database, so it isn’t technically “free” to run.

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**Author:** ![larryschul](https://avatars.discourse-cdn.com/v4/letter/l/eada6e/32.png) [@larryschul](https://forums.percona.com/u/larryschul)\
**Post date:** [September 27, 2022, 4:58pm UTC](https://forums.percona.com/t/log-block-checksum-mismatch/17313/3 "2022-09-27T16:58:05Z")

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long story short… this question is no longer a valid one based on other changes i have made… backups are running… thanks for the reply 🙂

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**Author:** ![Michael\_Coburn](https://sea1.discourse-cdn.com/flex019/user_avatar/forums.percona.com/michael_coburn/32/18_2.png) [@Michael\_Coburn](https://forums.percona.com/u/Michael_Coburn)\
**Post date:** [September 27, 2022, 6:22pm UTC](https://forums.percona.com/t/log-block-checksum-mismatch/17313/4 "2022-09-27T18:22:14Z")

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