…MySQL to use reasonable global buffers, such as innodb_buffer_size, key_buffer_size etc, you have reasonable amount of connections but yet MySQL… and look for memory information block, which can use …) File system 294352 (82672 + 211680) Lock system 318875832 (318747272 + 128560) Recovery system 0 …
Post: ext4 vs xfs on SSD
March 15, 2012 By 23 Comments
…for many modern Linux system, I am getting a lot of question if this is good for …to consider. Starting the MySQL 5.1 + InnoDB-plugin and later MySQL 5.5 (or …file-num=1 –file-extra-flags=direct –file-fsync-freq=0 –file-io-mode=sync –file-block-size=16384 –report-interval=10 run | tee -a run$size…
Post: Aligning IO on a hard disk RAID – the Theory
June 9, 2011 By 15 Comments
… blocks bigger than 4k (page size) on Linux unless you are using HugePages). Some file systems let you set stripe width and stripe unit size… bearing disks) with 64k stripe unit size and 4k file system block size, here’s how we would create the file system: xfs – mkfs.xfs -b 4k… above). So on such a system, when creating file systems with fdisk, don’t use the default value for a start sector, instead use…
Post: Make your file system error resilient
August 24, 2011 By 8 Comments
…Block count: 3630694400 Reserved block count: 0 Free blocks: 3616208434 Free inodes: 226918374 First block: 0 Block size: 4096 Fragment size: 4096 Reserved GDT blocks: 316 Blocks…file system errors are reported back to MySQL…
Post: Ultimate MySQL variable and status reference list
January 8, 2011 By 4 Comments
… MySQL manual, especially the option …files_on_createblogpercona.commanual Key_blocks_not_flushedblogpercona.commanual Key_blocks_unusedblogpercona.commanual Key_blocks….commanual max_seeks_for_keyblogpercona.commanual max_…sysdate_is_nowblogpercona.commanual system_time_zoneblogpercona.commanual …
Post: Living with backups
November 6, 2008 By 28 Comments
… memory should anything ask for the same block again. That happens for as long as it does not get flushed. MySQL obviously takes advantage… with the system cache. By specifying O_DIRECT flag when opening a file, an application tells the system to bypass the cache for it… a file that was opened with O_DIRECT flag, the file needs to be aligned to the file system block size, so usually it means the size…
Post: Helgrinding MySQL with InnoDB for Synchronisation Errors, Fun and Profit
November 24, 2011 By 2 Comments
…block (mem0mem.c:333) ==9090== by 0x6B66F3B: log_init (mem0mem.ic:443) ==9090== by 0x6BC63B0: innobase_start_or_create_for_mysql…system mutex, and log_get_lsn acquires it.. ==9090== Possible data race during write of size… bytes inside global var “os_n_file_writes” ==9090== declared at os0file….
Post: Evaluating IO subsystem performance for MySQL Needs
March 5, 2008 By 23 Comments
… system. What I usually look for MySQL is performance in random reads and random writes. Sequential reads and writes are rarely the problem for… Extra file open flags: 16384 1 files, 128Mb each 128Mb total file size Block size 16Kb Number of random requests for random IO: 1000000 Read/Write ratio for…
Post: Effect from innodb log block size 4096 bytes
January 3, 2011 By 18 Comments
…-block-size=4096 in Percona Server to get better throughput, but later Dimitri in his article MySQL Performance… innodb_log_buffer_size=8M innodb_log_files_in_group=2 innodb_log_file_size=4G innodb_adaptive_… graph ( user and system) for both cases: You may see with 4096 block size USER and SYS CPU …
Post: Side load may massively impact your MySQL Performance
November 13, 2011 By 7 Comments
…size=1100000 –mysql-user=msandbox –mysql-password=msandbox –mysql-socket=/tmp/mysql_sandbox5516.sock run [root@localhost msb_ps_5_5_15]# time mysqldump –defaults-file…for what is single hard drive on this test system. It is worth to note MySQL actually uses midpoint insertion for…_old_blocks_time…
