Search Results for: recover corrupted innodb

How to move the InnoDB log sequence number (LSN) forward

This post focuses on the problem of the InnoDB log sequence number being in the future. Preface: What is an InnoDB log sequence number? The Log sequence number (LSN) is an important database parameter used by InnoDB in many places. The most important use is for crash recovery and buffer pool purge control. Internally, the InnoDB […]

Why you can’t rely on a replica for disaster recovery

A couple of weeks ago one of my colleagues and I worked on a data corruption case that reminded me that sometimes people make unsafe assumptions without knowing it. This one involved SAN snapshotting that was unsafe. In a nutshell, the client used SAN block-level replication to maintain a standby/failover MySQL system, and there was […]

Recover BLOB fields

For a long time long types like BLOB, TEXT were not supported by Percona InnoDB Recovery Tool. The reason consists in a special way InnoDB stores BLOBs. An InnoDB table is stored in a clustered index called PRIMARY. It must exist even if a user hasn’t defined the primary index. The PRIMARY index pages are […]

Recovery beyond data restore

Quite frequently I see customers looking at MySQL recovery as on ability to restore data from backup which can be far from being enough to restore the whole system to operating state, especially for complex systems. Instead of looking just at data restore process you better look at the whole process which is required to […]

Recovering Innodb table Corruption

Assume you’re running MySQL with Innodb tables and you’ve got crappy hardware, driver bug, kernel bug, unlucky power failure or some rare MySQL bug and some pages in Innodb tablespace got corrupted. In such cases Innodb will typically print something like this: InnoDB: Database page corruption on disk or a failed InnoDB: file read of […]

Innodb Undelete and Sphinx Support

At Percona we are pleased to announce couple of services which should be helpful to MySQL Community and which are not offered by MySQL, Oracle and other companies I know about. First we now do Data Recovery for MySQL. We’re mainly focused on Innodb with this one because it has distinct page structure which allows […]

Magic Innodb Recovery self healing

We have certain type of the table corrupting with Innodb, as it is limited to only one particular index on one particular table type it is likely to be Innodb bug but Heikki currently could not find what could be causing it. Happily as we have data stored in many tables of same format rather […]

MySQL Crash Recovery

MySQL is known for its stability but as any other application it has bugs so it may crash sometime. Also operation system may be flawed, hardware has problems or simply power can go down which all mean similar things – MySQL Shutdown is unexpected and there could be various inconsistences. And this is not only […]

Percona XtraDB Cluster 5.6.21-25.8 is now available

Percona is glad to announce the new release of Percona XtraDB Cluster 5.6 on Novmeber 25th 2014. Binaries are available from downloads area or from our software repositories. We’re also happy to announce that Ubuntu 14.10 and CentOS 7 users can download, install, and upgrade Percona XtraDB Cluster 5.6 from Percona’s software repositories. Based on […]