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/ ------------------------------------------------------------------------------ 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
