… right decision. Second is the configuration issue – which can be hardware configuration such as redundant network paths…problem on single node only such as disk failing in RAID, resync initiated, BBU starting “…. Yet the problem is it is very hard to automatically detect the difference between these …
Post: Heikki Tuuri answers to Innodb questions, Part II
November 4, 2007 By 13 Comments
… buffering efficiently. Q30: Question about using solid state disks for storing ib_log* files; I know that … is a somewhat trivial question, but it’s hard to find a good answer to it while …of the available RAM as its file cache. The ideal configuration in a dedicated server is: set innodb_flush_…
Post: Sysbench evaluation of iSCSI performance
July 6, 2006 By 2 Comments
… so small between these configuration even with large number of threads – we’re speaking about 16 SCSI disks on high end and… tablespace IO bound, which does not really benefit from multiple hard drives. SCSI drive getting slower than Serial ATA on large… iSCSI allows to get much larger number of hard drives connected + easy roaming of hard drives between nodes while overhead should be…
Post: How much overhead DRDB could cause ?
June 2, 2008 By 4 Comments
… DRBD. Your reads are going to be serviced from local hard drive and it is only writes which suffer overhead of…. Moreover these operation could cause (depending on file system and configuration) more synchronous IO operations – MySQL binary logs are not preallocated… DRBD is configured with maximum durability settings. So overhead can vary a lot depending on the speed of the disk subsystem and…
Post: Content delivery system design mistakes
February 11, 2007 By 9 Comments
… works if configured well. In this case however the problem was zero TTL set in DNS configuration. This … you have storage build from large number of hard drives. This problem is fixed in Lighttpd 1…. static content and serving static content from the disk are different tasks and should not be mixed. …
Post: Side load may massively impact your MySQL Performance
November 13, 2011 By 7 Comments
…have relatively little CPU needs and be bound by disk. Also these are just 2 “threads” running on …now have 2 threads competing for what is single hard drive on this test system. It is worth …buffer pool replacement policy . Unfortunately by default it is configured in a way it is quite useless. The …
Post: InnoDB, InnoDB-plugin vs XtraDB on fast storage
January 13, 2010 By 13 Comments
…about box ). On storage configuration: FusionIO 160GB SLC and 320GB MLC cards are configured in software …used partition on regular RAID10 with regular hard drives, here I followed Yoshinori Matsunobu’…InnoDB-plugin. Now on CPU usage and disk utilization. Disk throughput: CPU (user) usage: Even with…
Post: Virtualization and IO Modes = Extra Complexity
March 21, 2011 By 12 Comments
…of troubles with fsync() not flushing hard drive write cache and so potential hard drives can be lost on … in case there is no disk seek we need to wait for disk head to make a full …whenever the problem is related to VirtualBox or some configuration issue. Things may be working correctly in your case…
Comment: Server Outages at Percona
August 11, 2011 By 12 Comments
… us. This server had a six-disk RAID5 configured as its only logical drive. One of these disks failed, and we did not…. Because the RAID controller was trying to continue using the disks, essential files became badly damaged. This happened because EXT3 was… missed due to staff turnover — a reminder that it’s hard to be overly attentive or too paranoid about the state…
Post: Evaluating IO subsystem performance for MySQL Needs
March 5, 2008 By 23 Comments
… Let us now repeat the tests for WriteBack cache configuration: We get 4735.27 Requests/sec from 1 … This is important lesson – even if you have many hard drives you can’t really get advantage of …just stored in controller cache and flushed to the disk in background – in this case there is little …
