…+——————–+ | A | | B | | C | +——————–+ 3 rows in set (0.00 sec) mysql> select count(*) from A; +———-+ | count(*) | +———-+ | 2359296 | +———-+ 1 row … of operation. You can also use Percona Xtrabackup, LVM or other database backup approach which does not …
Post: How to Monitor MySQL with Percona's Nagios Plugins
February 22, 2012 By 8 Comments
… that caused downtime for our customers: Failed or full LVM snapshots. LVM backup strategies can fail to delete snapshots after finishing, sometimes… happen at inconvenient times. The pmp-check-mysql-file-privs plugin checks whether MySQL owns every file and directory within its data… down for a system reboot. The pmp-check-mysql-pidfile plugin verifies that MySQL‘s PID file exists. Evidence of contention in…
Post: LVM Configuration mistake to Avoid
July 9, 2008 By 10 Comments
One of our customers was setting up box for MySQL LVM backups. The box had 2 RAID volumes (internal drives and … volumes were configured as different “volume groups”. Volume groups in LVM live completely isolated life and you can’t use space….S That would be interested to benchmark one day how LVM performs in shapshot mode in case undo space is stored…
Post: Reasons for MySQL Replication Lag
July 29, 2011 By 6 Comments
… can cause serve performance degradation. Configuration Changes Have you changed MySQL configuration ? OS Configuration or Hardware configuration or could have anyone… as increasing buffer pool size could cause performance problems. MySQL Restart MySQL Restarts may include recovery time but what is the most… forms. It can be you running backup through xtrabackup or LVM snapshot, RAID controller doing RAID validation, some centrally kicked of…
Post: Estimating Undo Space needed for LVM Snapshot
June 9, 2008 By 5 Comments
We know MySQL Backups using LVM are pretty cool (check out mylvmbackup) or MMM though it is quite typical LVM is not configurable properly to be usable for MySQL Backups. Quite frequently I find LVM installed on the… etc are also possible trouble makers. Third,Use dedicated LVM volume for MySQL Instance. This is good idea for many reason and…
Post: Disaster: LVM Performance in Snapshot Mode
February 5, 2009 By 55 Comments
… general IO performance in this case – it is not something MySQL related. I tested things on RHEL5, RAID10 volume with 6… any system doing writes to experience the “performance shock” when LVM snapshot is created with greatly reduced capacity which when will… (in particular sequential file reads). If you’ve done some LVM performance tests yourself or will be repeating mine (parameters posted…
Post: Aligning IO on a hard disk RAID – the Benchmarks
June 9, 2011 By 11 Comments
… performance with different IO alignment, not different MySQL configurations, I didn’t try out different MySQL versions or settings. Moreover, I have…-87 with the following my.cnf configuration: [mysqld] datadir=/data/mysql socket=/var/run/mysqld/mysqld.sock innodb_file_per_table…. Neither IO alignment nor file size made any difference. Adding LVM here reduced single-thread performance by 5-10%. Sequential write…
Post: Aligning IO on a hard disk RAID – the Theory
June 9, 2011 By 15 Comments
… point. Let’s get down one more level: LVM If you are using LVM, you want to make sure it does not… 256k RAID stripe elements, I would have ended up with LVM physical extent starting somewhere in the middle of the stripe… in the process when using pvcreate to initialize disk for LVM use, the two options you are interested in are –dataalignment…
Post: Using LVM for MySQL Backup and Replication Setup
August 21, 2006 By 53 Comments
If someone asks me about MySQL Backup advice my first question would be if they have LVM installed or have some systems… later mounted same as original file system Why snapshot based MySQL backups are great ? There are number of reasons: Almost Hot…) Extract/Copy database to the slave database directory. 10) Start MySQL Server. Wait for it to perform recovery. 11) Use CHANGE…
Post: No more MySQL Crash Safe Replication in 5.0 ?
January 29, 2008 By 7 Comments
… functionality was usable is cloning Slave->Slave by use of LVM without pausing replication (so you can get consistent master position…. Until this issue is fixed getting Crash Safe replication with MySQL is not impossible but surely more complicated and has much…. Innodb during recovery also prints position in the MySQL binary log: InnoDB: Last MySQL binlog file position 0 589600615, file name ./galax…
