quick question – the xfs_freeze feature is really killer when one wants to do consistent snapshots/backup of database directories, etc. Is there anything similar in ext4 or is the benchmark of ext4 +lvm (which I know allows this) on par with xfs_freeze (without lvm) ?
Comment: How FLUSH TABLES WITH READ LOCK works with Innodb Tables
March 24, 2012 By 20 Comments
… what is recoverable”. Even without Flush tables with read lock, LVM snapshot should be recoverable 100% of the time. You might… there have been very few of them. Typically problems with LVM snapshots can originate from either not having log files and…
Comment: How FLUSH TABLES WITH READ LOCK works with Innodb Tables
March 24, 2012 By 20 Comments
…: For one, how is, in the case of mylvmbackup, the LVM snapshot implemented? Is it not atomic in itself, so that… writes can happen while the snapshot it being made? If LVM snapshots are atomic, yet a FTWRL InnoDB snapshot can be…
Comment: How FLUSH TABLES WITH READ LOCK works with Innodb Tables
March 26, 2012 By 20 Comments
… be related to Innodb itself or how XFS plays with LVM or something. As mark mentions – indeed there are known problems…
Comment: How FLUSH TABLES WITH READ LOCK works with Innodb Tables
March 23, 2012 By 20 Comments
… we speak about Innodb tables and backup with Xtrabackup or LVM we do not really need it. What we need is…
Post: Best kept MySQLDump Secret
March 23, 2012 By 11 Comments
… the duration of operation. You can also use Percona Xtrabackup, LVM or other database backup approach which does not relay on…
Post: Estimating Undo Space needed for LVM Snapshot
June 9, 2008 By 5 Comments
… being remapped it is read from the undo location. The LVM Snapshots versioning is however different from database Multi Versioning because… overhead, and there is no space requirements. Another issue with LVM snapshot it may convert pretty much sequential IO done while… recreation etc are also possible trouble makers. Third,Use dedicated LVM volume for MySQL Instance. This is good idea for many…
Post: Disaster: LVM Performance in Snapshot Mode
February 5, 2009 By 55 Comments
… bottleneck. This is exactly the case with LVM Number of customers have reported the LVM gives very high penalty when snapshots are… 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: SSD, XFS, LVM, fsync, write cache, barrier and lost transactions
March 2, 2009 By 32 Comments
… bad, we have no good replacement yet) and I tried LVM under XFS. With write-cache ON and default mount options…. with barrier) I have 5250 writes / s, this is because LVM ignores write barriers (see http://dammit.lt/2008/11/03… is good ones – another are for research 4. XFS without LVM is putting barrier option which decreases write performance a lot
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…
