Emergency

Search Results for: innodb data recovery

A recovery trivia or how to recover from a lost ibdata1 file

A few day ago, a customer came to Percona needing to recover data. Basically, while doing a transfer from one SAN to another, something went wrong and they lost the ibdata1 file, where all the …

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Upcoming webinar on Data Recovery for MySQL

I’ll be giving a 40-50 minute long webinar on 26th of April on data recovery for MySQL. Almost every long serving DBA has been faced with the task of recovering data from a database, whether …

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InnoDB Flushing: Theory and solutions

I mentioned problems with InnoDB flushing in a previous post. Before getting to ideas on a solution, let’s define some terms and take a look into theory. The two most important parameters for InnoDB performance …

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InnoDB Flushing: a lot of memory and slow disk

You may have seen in the last couple of weekly news posts that Baron mentioned we are working on a new adaptive flushing algorithm in InnoDB. In fact, we already have three such algorithms in …

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What is innodb_support_xa?

A common misunderstanding about innodb_support_xa is that it enables user-initiated XA transactions, that is, transactions that are prepared and then committed on multiple systems, with an external transaction coordinator. This is actually not precisely what …

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How InnoDB handles REDO logging

Xaprb (Baron) recently blogged about how InnoDB performs a checkpoint , I thought it might be useful to explain another important mechanism that affects both response time and throughput – The transaction log.

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How long is recovery from 8G innodb_log_file

In my previous posts I highlighted that one of improvements in Percona Server is support of innodb_log_file_size > 4G. This test was done using Percona Server 5.5.7, but the same performance expected for InnoDB-plugin and …

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Data Corruption, DRBD and story of bug

Working with customer, I faced pretty nasty bug, which is actually not rare situation , but in this particular there are some lessons I would like to share. The case is pretty much described in …

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Lost innodb tables, xfs and binary grep

Before I start a story about the data recovery case I worked on yesterday, here’s a quick tip – having a database backup does not mean you can restore from it. Always verify your backup …

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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 …

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