Excerpts from John Wyzer's message of 2011-04-29 10:46:08 -0400: > Currently on > commit 7cf96da3ec7ca225acf4f284b0e904a1f5f98821 > Author: Tsutomu Itoh <t-i...@jp.fujitsu.com> > Date: Mon Apr 25 19:43:53 2011 -0400 > Btrfs: cleanup error handling in inode.c > > merged into 2.6.38.4 > > I'm on a btrfs filesystem that has been used for some time. Let's say nine > months. Very recently I noticed performance getting worse and worse. > Most of the time it feels as if the system is just busy with iowait. > Write and read performance during random access is mostly around 2MB/s, > sometimes 1MB/s or slower. It's better for big files which can be read with > about > 6-9MB/s. The disk is a reasonably recent SATA disk (WDC_WD3200BEVT) so 30MB/s > or 40MB/s linear reading should not be a problem. > > rootfs 291G 242G 35G 88% / > > I tried btrfs filesystem defragment -v / but did not notice any improvement > after that. > > Is this a known phenomenon? :-) >
Sounds like you're hitting fragmentation, which we can confirm with latencytop. Please run latencytop while you're seeing poor performance and take a look at where you're spending most of your time. -chris -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
