… Linux system, I am getting a lot of question if this is good for SSD, or something else (i.e. xfs) should… in 100 do cd /mnt/stec sysbench –test=fileio –file-num=1 –file-total-size=${size}G prepare sync echo 3 > /proc…=$numthreads –rand-init=on –file-num=1 –file-extra-flags=direct –file-fsync-freq=0 –file-io-mode=sync –file-block-size=16384 –report-interval…
Comment: ext4 vs xfs on SSD
March 19, 2012 By 23 Comments
…) disks. The file systems on this “inherited” machine default to ext4, but I had Domas’ claims in my mind that xfs is superior… repeated the sysbench run. Up to 8 threads xfs was few percent faster (~10% on average). At 16 threads … lost it’s bite, but was still constantly better than xfs. I did not look deeper into this, but used the…
Comment: Which Linux distribution for a MySQL database server? A specific point of view.
February 24, 2012 By 37 Comments
Hi. After choosing a distribution, are there specific settings that should be chosen for an OLTP DB? – file system? chunks? sizes? ext4 or xfs? – schedulers?
Post: Make your file system error resilient
August 24, 2011 By 8 Comments
… over systems like XFS will not continue if consistency problems are discovered. So how can you check what error behavior mode your file system… filesystem data structures which may be affects one file will take out whole file system. I do not think these concerns are valid… file system check on startup which is normally done once per so many mounts or so many days. Large partitions with many files…
Post: Lost innodb tables, xfs and binary grep
November 9, 2010 By 11 Comments
… facts about the system and how data was lost: MySQL had a dedicated partition on XFS file system Server was running innodb_file_per_table… but not the data so no data was written to file system. Mind however that restoring a backup could have been fatal… one of the supported files. What we did is we simply ran page_parser on the (already) unmounted file system treating it as…
Post: Aligning IO on a hard disk RAID – the Theory
June 9, 2011 By 15 Comments
… do anything to align InnoDB pages – file system takes care of it (assuming you configure the file system correctly). I would however mention couple…. File system File system plays very important role here – it maps files logical address to physical address (at a certain level) so when writing a file, file system… stripe unit size and 4k file system block size, here’s how we would create the file system: xfs – mkfs.xfs -b 4k -d su=64k…
Post: Working with many files and file system fragmentation
March 18, 2008 By 11 Comments
… performance difference was huge – we could read single file at 80MB/sec while fragmented files only deliver about 2MB/sec – this is… does not do very good job preventing file fragmentation for large amount of growing files. It would be interesting to see how other filesystems deal with this problem, for example XFS with delayed…
Post: Aligning IO on a hard disk RAID – the Benchmarks
June 9, 2011 By 11 Comments
… to figure it out, but here’s what happened – for XFS file system on a raw partition I was using full partition size… in xfs when creating it and you don’t want or can’t format the file system. One thing to note however – files that were written before this was set may still be unaligned, though xfs defragmentation…
Comment: Disaster: LVM Performance in Snapshot Mode
February 9, 2009 By 55 Comments
…) and pointer-based block-map technologies of the log structured file systems (WAFL, ZFS). With log structured filesystems you get snapshots practically… run “randomio” benchmark on ext3 filesystem and compared it with xfs. The difference with LVM snapshot is big. “randomio” opens its… the same with xfs on a large file – [root@udbqa006.sf2p ~]# mount /dev/mapper/VolGroup20-mysqldata on /data type xfs (rw,noatime,allocsize…
Post: SSD, XFS, LVM, fsync, write cache, barrier and lost transactions
March 2, 2009 By 32 Comments
… installing Ubuntu 8.10 which is currently running all this system. Originally I wanted to publish some nice benchmarks where InnoDB…_file_path=ibdata1:10M:autoextend innodb_file_per_table=1 innodb_log_buffer_size=8M innodb_log_files_in_group=2 innodb_log_file… all committed transactions even in case of system failure. Running this test with default XFS setting I saw SSD was doing 50…
