Re: Anyone using LVM for backing up?
Hi Tim, On Mon, Jun 22, 2009 at 4:41 PM, Little, Timothytlit...@thomaspublishing.com wrote: We have a 20 gig db (that includes the MYIs and MYDs and FRMs). We are wondering how long LVM snapshots take.. in that how long might the DB be read-locked? Do we have to read-lock it and flush tables? Are we talking half a second, ten-seconds, 20 minutes? It depends. Long-running queries will block FLUSH TABLES WITH READ LOCK, if you're using it, which will in turn block other queries. So FLUSH TABLES WITH READ LOCK itself can take a long time. If you're using only InnoDB tables you don't need to do that, you can just take the snapshot and go. Upon recovery on the other server you can find the binlog position in InnoDB's messages to the error log. There are a lot of subtleties to all of this, so maybe you can give a few more details about your setup. -- MySQL General Mailing List For list archives: http://lists.mysql.com/mysql To unsubscribe:http://lists.mysql.com/mysql?unsub=arch...@jab.org
Anyone using LVM for backing up?
We have a 20 gig db (that includes the MYIs and MYDs and FRMs). We are wondering how long LVM snapshots take.. in that how long might the DB be read-locked? Do we have to read-lock it and flush tables? Are we talking half a second, ten-seconds, 20 minutes? Currently, when we copy the raw files from one directory to another, it takes about 20 mins and brings the DB to it's proverbial knees. When we copy the files with the db server down, it takes 10 minutes or so. Tim... -- MySQL General Mailing List For list archives: http://lists.mysql.com/mysql To unsubscribe:http://lists.mysql.com/mysql?unsub=arch...@jab.org
Re: Anyone using LVM for backing up?
Hi Tim, We use LVM snapshots all the time. They are essentially instantaneous with our 90GB innodb database files. A command to generate the snapshot could be: sudo /usr/sbin/lvcreate --snapshot --name mysqlsqlbackup --size 15G / dev/system/data01 Please let me know if you have any questions. -Tom On Jun 22, 2009, at 4:41 PM, Little, Timothy wrote: We have a 20 gig db (that includes the MYIs and MYDs and FRMs). We are wondering how long LVM snapshots take.. in that how long might the DB be read-locked? Do we have to read-lock it and flush tables? Are we talking half a second, ten-seconds, 20 minutes? Currently, when we copy the raw files from one directory to another, it takes about 20 mins and brings the DB to it's proverbial knees. When we copy the files with the db server down, it takes 10 minutes or so. Tim... -- MySQL General Mailing List For list archives: http://lists.mysql.com/mysql To unsubscribe: http://lists.mysql.com/mysql?unsub=tmcgona...@online-buddies.com -- MySQL General Mailing List For list archives: http://lists.mysql.com/mysql To unsubscribe:http://lists.mysql.com/mysql?unsub=arch...@jab.org
Re: Anyone using LVM for backing up?
What we do to start is the following: ) open 2 windows to the server running the mysql instance ) in one window, ) run the mysql cli and issue command 'flush tables with read lock' ) stop the slave, if this is a running slave ) run either show master status or show slave status, whichever is appropriate, to get log position ) in the other window ) run the sync command several times ) create the snapshots ) back in the first window ) unlock that tables ) start the slave, if appropriate ) back in the other window ) mount the snapshots We do it this way to minimize the time the server we're syncing from is in read lock. If anyone sees any flaws in this, please let me know. There's a lot more, of course, involving rsync and change master. I just dealt with the beginning part. On Mon, Jun 22, 2009 at 3:41 PM, Little, Timothy tlit...@thomaspublishing.com wrote: We have a 20 gig db (that includes the MYIs and MYDs and FRMs). We are wondering how long LVM snapshots take.. in that how long might the DB be read-locked? Do we have to read-lock it and flush tables? Are we talking half a second, ten-seconds, 20 minutes? Currently, when we copy the raw files from one directory to another, it takes about 20 mins and brings the DB to it's proverbial knees. When we copy the files with the db server down, it takes 10 minutes or so. Tim... -- MySQL General Mailing List For list archives: http://lists.mysql.com/mysql To unsubscribe:http://lists.mysql.com/mysql?unsub=jlyons4...@gmail.com -- Jim Lyons Web developer / Database administrator http://www.weblyons.com
Re: Anyone using LVM for backing up?
Little, Timothy wrote: We have a 20 gig db (that includes the MYIs and MYDs and FRMs). We are wondering how long LVM snapshots take.. in that how long might the DB be read-locked? Do we have to read-lock it and flush tables? Take a look at mylvmbackup which takes care of flushing tables, creating and destroying the snapshot, etc: http://www.lenzg.net/mylvmbackup/ Expect a serious performance hit while the lvm snapshot is active. ds -- MySQL General Mailing List For list archives: http://lists.mysql.com/mysql To unsubscribe:http://lists.mysql.com/mysql?unsub=arch...@jab.org
