Comments on: Using LVM for MySQL Backup and Replication Setup http://www.mysqlperformanceblog.com/2006/08/21/using-lvm-for-mysql-backup-and-replication-setup/ Everything about MySQL Performance Sun, 07 Sep 2008 08:07:40 +0000 http://wordpress.org/?v=2.5.1 By: peter http://www.mysqlperformanceblog.com/2006/08/21/using-lvm-for-mysql-backup-and-replication-setup/#comment-345269 peter Sat, 16 Aug 2008 05:15:01 +0000 http://www.mysqlperformanceblog.com/2006/08/21/using-lvm-for-mysql-backup-and-replication-setup/#comment-345269 Richard, Indeed you can use log file size. Moreover if you have Innodb only tables you do not have to do flush tables with read locks. Unless you do DDL or modify mysql.* tables you should be fine. Richard,

Indeed you can use log file size. Moreover if you have Innodb only tables you do not have to do flush tables with read locks. Unless you do DDL or modify mysql.* tables you should be fine.

]]> By: Richard Bronosky http://www.mysqlperformanceblog.com/2006/08/21/using-lvm-for-mysql-backup-and-replication-setup/#comment-345260 Richard Bronosky Sat, 16 Aug 2008 04:35:19 +0000 http://www.mysqlperformanceblog.com/2006/08/21/using-lvm-for-mysql-backup-and-replication-setup/#comment-345260 CARP! Wordpress ate my lines that were supposed to have: /data/dev/mysql# mysql << MYSQL > FLUSH TABLES WITH READ LOCK; CARP! Wordpress ate my lines that were supposed to have:
/data/dev/mysql# mysql << MYSQL
> FLUSH TABLES WITH READ LOCK;

]]> By: Richard Bronosky http://www.mysqlperformanceblog.com/2006/08/21/using-lvm-for-mysql-backup-and-replication-setup/#comment-345258 Richard Bronosky Sat, 16 Aug 2008 04:31:43 +0000 http://www.mysqlperformanceblog.com/2006/08/21/using-lvm-for-mysql-backup-and-replication-setup/#comment-345258 Peter, It seems that the master_log_pos (Position as returned by SHOW MASTER STATUS;) is always equal to the file size of the bin-log file. At least that's what my tests reveal on a MyISAM InnoDB hybrid system. Is this always consistent? If so, then you should be able to create a slave from a master snapshot without having to have the information given by SHOW MASTER STATUS. Why does this matter? If your nightly backup doesn't capture master status, that shouldn't prevent you from sing it to create a slave. Here is a transcript... /data/dev/mysql# mysql < FLUSH TABLES WITH READ LOCK; > SHOW MASTER STATUS; > \! ls -lart mysql-bin*|tail -n1 > UNLOCK TABLES; > MYSQL File Position Binlog_Do_DB Binlog_Ignore_DB mysql-bin.000156 956920476 -rw-rw---- 1 mysql mysql 956920476 Aug 16 00:23 mysql-bin.000156 /data/dev/mysql# mysql < FLUSH TABLES WITH READ LOCK; > SHOW MASTER STATUS; > \! ls -lart mysql-bin*|tail -n1 > UNLOCK TABLES; > MYSQL File Position Binlog_Do_DB Binlog_Ignore_DB mysql-bin.000156 957115478 -rw-rw---- 1 mysql mysql 957115478 Aug 16 00:23 mysql-bin.000156 /data/dev/mysql# mysql < FLUSH TABLES WITH READ LOCK; > SHOW MASTER STATUS; > \! ls -lart mysql-bin*|tail -n1 > UNLOCK TABLES; > MYSQL File Position Binlog_Do_DB Binlog_Ignore_DB mysql-bin.000156 957218874 -rw-rw---- 1 mysql mysql 957218874 Aug 16 00:23 mysql-bin.000156 Peter,
It seems that the master_log_pos (Position as returned by SHOW MASTER STATUS;) is always equal to the file size of the bin-log file. At least that’s what my tests reveal on a MyISAM InnoDB hybrid system. Is this always consistent? If so, then you should be able to create a slave from a master snapshot without having to have the information given by SHOW MASTER STATUS. Why does this matter? If your nightly backup doesn’t capture master status, that shouldn’t prevent you from sing it to create a slave.

Here is a transcript…
/data/dev/mysql# mysql < FLUSH TABLES WITH READ LOCK;
> SHOW MASTER STATUS;
> \! ls -lart mysql-bin*|tail -n1
> UNLOCK TABLES;
> MYSQL
File Position Binlog_Do_DB Binlog_Ignore_DB
mysql-bin.000156 956920476
-rw-rw—- 1 mysql mysql 956920476 Aug 16 00:23 mysql-bin.000156
/data/dev/mysql# mysql < FLUSH TABLES WITH READ LOCK;
> SHOW MASTER STATUS;
> \! ls -lart mysql-bin*|tail -n1
> UNLOCK TABLES;
> MYSQL
File Position Binlog_Do_DB Binlog_Ignore_DB
mysql-bin.000156 957115478
-rw-rw—- 1 mysql mysql 957115478 Aug 16 00:23 mysql-bin.000156
/data/dev/mysql# mysql < FLUSH TABLES WITH READ LOCK;
> SHOW MASTER STATUS;
> \! ls -lart mysql-bin*|tail -n1
> UNLOCK TABLES;
> MYSQL
File Position Binlog_Do_DB Binlog_Ignore_DB
mysql-bin.000156 957218874
-rw-rw—- 1 mysql mysql 957218874 Aug 16 00:23 mysql-bin.000156

]]> By: robo http://www.mysqlperformanceblog.com/2006/08/21/using-lvm-for-mysql-backup-and-replication-setup/#comment-340639 robo Tue, 05 Aug 2008 19:58:36 +0000 http://www.mysqlperformanceblog.com/2006/08/21/using-lvm-for-mysql-backup-and-replication-setup/#comment-340639 Crazy question w/r/t LVM snapshots on a myisam slave: If updates via replication are not cached(further they invalidate cache?) then is it really necessary to "flush tables with read lock" or will "stop slave" be sufficient? Does the same apply to buffers? IE, we are already ok with running myisam tables, at cost of locking during the flush in the middle of a long select, is it really worth doing? Crazy question w/r/t LVM snapshots on a myisam slave: If updates via replication are not cached(further they invalidate cache?) then is it really necessary to “flush tables with read lock” or will “stop slave” be sufficient?
Does the same apply to buffers?
IE, we are already ok with running myisam tables, at cost of locking during the flush in the middle of a long select, is it really worth doing?

]]> By: battery http://www.mysqlperformanceblog.com/2006/08/21/using-lvm-for-mysql-backup-and-replication-setup/#comment-315298 battery Fri, 20 Jun 2008 01:37:09 +0000 http://www.mysqlperformanceblog.com/2006/08/21/using-lvm-for-mysql-backup-and-replication-setup/#comment-315298 [...]tape drive[...] [...]tape drive[...]

]]> By: Experiments with Running WordpressMU on EC2 « Hefta-Gaub Development Blog http://www.mysqlperformanceblog.com/2006/08/21/using-lvm-for-mysql-backup-and-replication-setup/#comment-267038 Experiments with Running WordpressMU on EC2 « Hefta-Gaub Development Blog Sun, 06 Apr 2008 00:13:42 +0000 http://www.mysqlperformanceblog.com/2006/08/21/using-lvm-for-mysql-backup-and-replication-setup/#comment-267038 [...] Another article that talks about LVM, MySQL Replication, and backups. [...] [...] Another article that talks about LVM, MySQL Replication, and backups. [...]

]]> By: Dennis Glorioso http://www.mysqlperformanceblog.com/2006/08/21/using-lvm-for-mysql-backup-and-replication-setup/#comment-255395 Dennis Glorioso Sat, 22 Mar 2008 00:50:56 +0000 http://www.mysqlperformanceblog.com/2006/08/21/using-lvm-for-mysql-backup-and-replication-setup/#comment-255395 We run MYSQL on Windows servers. We use a external NAS that Snapshots an immage of the Volume on other windows servers. We mount that image on a VMware like (vurtualbox) enviromemmt as a live enviroment if the server were to crash. If we are running My SQL on a Windows server Can we use the same FLUSH TABLES WITH READ LOCK command and UNLOCK TABLES to work with our snapshot (storagecraft) SW and directly mount this image as a failover for MySQL instead of using LVM? Also what command to use to hold the lock until snapshot is finished or will it stay in read only until UNLOCK TABLES is run We run MYSQL on Windows servers. We use a external NAS that Snapshots an immage of the Volume on other windows servers. We mount that image on a VMware like (vurtualbox) enviromemmt as a live enviroment if the server were to crash. If we are running My SQL on a Windows server Can we use the same FLUSH TABLES WITH READ LOCK command and UNLOCK TABLES to work with our snapshot (storagecraft) SW and directly mount this image as a failover for MySQL instead of using LVM? Also what command to use to hold the lock until snapshot is finished or will it stay in read only until UNLOCK TABLES is run

]]> By: LVM snapshots « Daniel’s weblog http://www.mysqlperformanceblog.com/2006/08/21/using-lvm-for-mysql-backup-and-replication-setup/#comment-247901 LVM snapshots « Daniel’s weblog Sun, 02 Mar 2008 20:57:19 +0000 http://www.mysqlperformanceblog.com/2006/08/21/using-lvm-for-mysql-backup-and-replication-setup/#comment-247901 [...] Beware that “special” files like databases needs special care as written here or here so they stay in consistent state and as it seems even then it might be a problem when data nad db [...] [...] Beware that “special” files like databases needs special care as written here or here so they stay in consistent state and as it seems even then it might be a problem when data nad db [...]

]]> By: MyLVM backup http://www.mysqlperformanceblog.com/2006/08/21/using-lvm-for-mysql-backup-and-replication-setup/#comment-246289 MyLVM backup Tue, 26 Feb 2008 20:05:21 +0000 http://www.mysqlperformanceblog.com/2006/08/21/using-lvm-for-mysql-backup-and-replication-setup/#comment-246289 [...] Installera mylvmbackup  eller följ guiden på mysqlperformanceblog [...] [...] Installera mylvmbackup  eller följ guiden på mysqlperformanceblog [...]

]]> By: Marcus Herou http://www.mysqlperformanceblog.com/2006/08/21/using-lvm-for-mysql-backup-and-replication-setup/#comment-246259 Marcus Herou Tue, 26 Feb 2008 16:14:50 +0000 http://www.mysqlperformanceblog.com/2006/08/21/using-lvm-for-mysql-backup-and-replication-setup/#comment-246259 Fuck, it is totally trimmed by wordpress... Fuck, it is totally trimmed by wordpress…

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