On 29/08/2011 06:05, marius adrian popa wrote: > On Mon, Aug 29, 2011 at 1:14 AM, Adriano dos Santos Fernandes > <adrian...@gmail.com> wrote: >> All, >> >> After I bought a new machine, I reinstalled Ubuntu in new HDD with ext4 >> filesystem. >> >> While the new machine has much better CPU than the old one, I noticed >> the build being very slow where Firebird was creating databases. >> >> I found that mounting the ext4 partition with barrier=0 parameter >> decreased the performance from more than 2 minutes to less than 50s in >> the build. >> >> But changing this parameter seems to not make ext4 at least safe as >> ext3. So I reverted it and adjust the build to turn FW=off for the >> internal databases. That didn't become fast as barrier=0, but was >> acceptable (around 1 minute). >> >> Now I tried to run tcs and saw it's completely unpractical. So I started >> to test just "create database" performance. >> >> The numbers are around this: >> >> ntfs: 0.2s >> ext3 default (barrier=0): 0.1s >> ext3 (barrier=1): 0.8s >> ext4 default (barrier=1): 2.8s >> >> I removed the O_SYNC flag in posix.cpp and it makes ext4 similar to ext3. >> >> So I have some questions: >> >> Are we doing something wrong? >> >> Does ext4 just f*ks? >> >> Is ext3 good just until you need what it markets, i.e., you should pray >> for no hardware crashes or power loss? >> >> What about some new parameter to ignore FW=on for who just don't care? >> (tests, development, etc) > you are not the only one that observed db/vm performance issues with ext4 > maybe you need to mount it with data=writeback > > http://blog.smartlogicsolutions.com/2009/06/04/mount-options-to-improve-ext4-file-system-performance/ > > I don't tested ext4 with writeback yet, but this ext3 barrier=1 (0.8s time) was mounted with data=ordered. While it's still *too slow*, it's far away from ext4 mounted with the same options.
Adriano ------------------------------------------------------------------------------ EMC VNX: the world's simplest storage, starting under $10K The only unified storage solution that offers unified management Up to 160% more powerful than alternatives and 25% more efficient. Guaranteed. http://p.sf.net/sfu/emc-vnx-dev2dev Firebird-Devel mailing list, web interface at https://lists.sourceforge.net/lists/listinfo/firebird-devel
