… for backup purpose, boxes with 64 300GB SAS drives, 3 raid controllers and 192GB of RAM. These servers will run a… MySQL instances. The original idea was to configure them with raid-10 + LVM, making sure to stripe the LV when we… to explain this, maybe it is related to better raid controller write cache use. Even the fairly slow gzip-1 mode works…
Comment: ZFS on Linux and MySQL
May 24, 2013 By 17 Comments
@JDempster: I could give the SSD to xfs also with Flashcache and the like. Don’t forget all these jbods have a raid controller write cache in front of them. I also did the Innodb tuning. @Nils: no fuse, direct kernel support. Look here: http://zfsonlinux.org/
Comment: Virident vCache vs. FlashCache: Part 1
May 17, 2013 By 3 Comments
…-effective price point, or I might end up saturating my RAID controller such that now it becomes the bottleneck. Also, keep… closer to memory speed than a regular SSD or HDD RAID), I can write data out to spinning disk at a… Facebook FlashCache. I’d never even heard of the STEC caching solution prior to your comment. Maybe another Perconian will have…
Comment: Virident vCache vs. FlashCache: Part 2
May 17, 2013 By 3 Comments
…– The backing disk on this server is an 8-disk RAID 10 of fairly standard SAS drives. Your proposed test scenario… case requirement that the working set *did* fit into the cache device. I am curious, however, how FlashCache/vCache would perform…
Post: Query Profiling with MySQL: Bypassing caches
September 12, 2007 By 6 Comments
… Caches State of CPU cache may affect query execution speed but only lightly, the hardware IO cache may however cause dramatic difference. Hardware RAID cache is the one but more important SAN caches which can be pretty big. So How can you bypass these caches? For MySQL Caches…
Post: Evaluating IO subsystem performance for MySQL Needs
March 5, 2008 By 23 Comments
… by RAID cache and uncached IO performance. We’re interested in cached reads because they may show latency to the RAID cache if RAID read cache is enabled. If it is disabled you may be reading from Drives cache or even drives…/sec – so the RAID cache on this drive can do about 13.000 16K reads/sec from the cache, not bad at all…
Post: Aligning IO on a hard disk RAID – the Benchmarks
June 9, 2011 By 13 Comments
…, 8 ports Cache | 128MB Memory, BBU Present BBU | 100% Charged, Temperature 34C, isSOHGood= VirtualDev Size RAID Level Disks SpnDpth Stripe Status Cache ========== ========= ========== ===== ======= ====== ======= ========= 0… show you. First one is with RAID controller set to WT cache: The second is with WB cache: I couldn’t figure out…
Post: Setting up XFS on Hardware RAID -- the simple edition
December 16, 2011 By 9 Comments
… RAID minutia. Make sure you cover the following: RAID type (usually 5 or 1+0) RAID stripe size BBU enabled with Write-back cache only No read cache or read-ahead No drive write cache enabled Partitioning…
Post: SSD, XFS, LVM, fsync, write cache, barrier and lost transactions
March 2, 2009 By 32 Comments
… is comparable with RAID 10 So in conclusion to warranty Durability with SSD we have to disable write-cache which can affect… write cache ( with following performance penalty, how much we need to test yet) 3. Possible solution could be put SSD into RAID controller with battery-backup-ed write cache, but I am not sure what is…
Post: RAID System performance surprises
March 5, 2008 By 7 Comments
… also tend to accumulate in predictable fashion. If you have RAID controller this well may not be the case – to protect your data RAID controller may implement bunch of algorithms which can affect performance… according to the docs. During this time battery backed up cache will be disabled and system will operate with write through…
