From: Brian Warner <warner@allmydata.com>
Date: Thu, 21 Aug 2008 20:59:01 +0000 (-0700)
Subject: docs/filesystem-notes.txt: add notes about enabling the 'directory index' feature... 
X-Git-Url: https://git.rkrishnan.org/architecture.txt?a=commitdiff_plain;h=a086b8cf6b6a61a1b7a39be1dcd85f1bcfc44ae1;p=tahoe-lafs%2Ftahoe-lafs.git

docs/filesystem-notes.txt: add notes about enabling the 'directory index' feature on ext3 filesystems for storage server lookup speed
---

diff --git a/docs/filesystem-notes.txt b/docs/filesystem-notes.txt
new file mode 100644
index 00000000..34e02029
--- /dev/null
+++ b/docs/filesystem-notes.txt
@@ -0,0 +1,18 @@
+
+Tahoe storage servers use a large number of subdirectories to store their
+shares on local disk. This format is simple and robust, but depends upon the
+local filesystem to provide fast access to those directories.
+
+= ext3 =
+
+For moderate- or large-sized storage servers, you'll want to make sure the
+"directory index" feature is enabled on your ext3 directories, otherwise
+share lookup may be very slow. Recent versions of ext3 enable this
+automatically, but older filesystems may not have it enabled.
+
+$ sudo tune2fs -l /dev/sda1 |grep feature
+Filesystem features:      has_journal ext_attr resize_inode dir_index filetype needs_recovery sparse_super large_file
+
+If "dir_index" is present in the "features:" line, then you're all set. If
+not, you'll need to use tune2fs and e2fsck to enable and build the index. See
+this page for some hints: http://wiki.dovecot.org/MailboxFormat/Maildir .