… enough space available on the volume…. The problem was internal and external volumes were configured as different “volume groups“. Volume groups in LVM live completely isolated life and you can’t use space from one volume group for…
Comment: LVM Configuration mistake to Avoid
July 10, 2008 By 10 Comments
… onto the LVM configuration. We had only two physical volumes left: a ‘slow’ 146GB system volume and a ‘fast’ 72GB data volume. The idea… snapshot for a logical volume must be done within the same volume group. Merging the two physical volumes into one volume group was no option because… of those physical volumes. The end result is that we stuck to two physical volumes, two volume groups and two logical volumes. We had to…
Post: Aligning IO on a hard disk RAID – the Theory
June 9, 2011 By 18 Comments
… pvcreate it is also a good idea to use appropriate Volume Group Physical Extent Size for vgcreate – I think default 4MB should… format it with mkfs directly or add it as an LVM physical volume. This let’s you avoid any mistakes when working… Further down below on the storage stack there’s a group of RAID stripe units (elements) sometimes referred to as a…
Comment: Using LVM for MySQL Backup and Replication Setup
August 18, 2011 By 53 Comments
… slaves run on LVM‘s which have already occupied most of the file system space in that particular volume group they are residing… long as they issues queries on tar backup on another volume it wont impact our performance since it has nothing to… , will that work ? and will that impact on the original volume in any way ?> what could be other solution to this…
Post: Recovering Linux software RAID, RAID5 Array
August 27, 2011 By 2 Comments
… way you probably will be unable to mount it, find LVM volumes on it etc, and you can go back and correct… Read ahead sectors 0 So we have RAID volume back but LVM shows this volume as NOT available and so it can’t… be easily fixed: ReadyNAS1:/# vgchange -a y 1 logical volume(s) in volume group “c” now active Lets check if the file system…
Comment: LVM Configuration mistake to Avoid
July 11, 2008 By 10 Comments
… create temporary volume to consume all space on slow physical volume. Add fast physical volume to the same volume group. Create your MySQL LVM Volume on it. Now drop the temporary “space consumer” you had on the slow volume…
Post: How Percona does a MySQL Performance Audit
November 24, 2008 By 17 Comments
… you will establish a solid relationship with the team, and group involvement early on is a good start to this. What… last three commands are for giving me information about LVM devices, volume groups, and logical volumes. At this point, unless I’ve seen something…
Post: Aligning IO on a hard disk RAID – the Benchmarks
June 9, 2011 By 13 Comments
… over 1TB in size. When I added LVM on top however, I made the logical volume slightly below 1TB. Investigating this I… = 128M innodb_log_file_size = 64M innodb_log_files_in_group = 2 innodb_read_io_threads = 8 innodb_write_io_threads…. Neither IO alignment nor file size made any difference. Adding LVM here reduced single-thread performance by 5-10%. Sequential write…
