From: Zheng Liu Subject: [PATCH 3/3] mke2fs: document bigalloc and cluster-size Date: Sun, 13 Jan 2013 17:08:15 +0800 Message-ID: <1358068095-9034-3-git-send-email-wenqing.lz@taobao.com> References: <1358068095-9034-1-git-send-email-wenqing.lz@taobao.com> Cc: Zheng Liu To: linux-ext4@vger.kernel.org Return-path: Received: from mail-da0-f45.google.com ([209.85.210.45]:40061 "EHLO mail-da0-f45.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751772Ab3AMIy4 (ORCPT ); Sun, 13 Jan 2013 03:54:56 -0500 Received: by mail-da0-f45.google.com with SMTP id w4so1382444dam.32 for ; Sun, 13 Jan 2013 00:54:56 -0800 (PST) In-Reply-To: <1358068095-9034-1-git-send-email-wenqing.lz@taobao.com> Sender: linux-ext4-owner@vger.kernel.org List-ID: From: Zheng Liu Bigalloc feature has been used for a long time, but the documentation in mke2fs is still missing. So add it. Signed-off-by: Zheng Liu --- misc/mke2fs.8.in | 11 +++++++++++ 1 file changed, 11 insertions(+) diff --git a/misc/mke2fs.8.in b/misc/mke2fs.8.in index d4fbe00..ca3083d 100644 --- a/misc/mke2fs.8.in +++ b/misc/mke2fs.8.in @@ -187,6 +187,11 @@ Check the device for bad blocks before creating the file system. If this option is specified twice, then a slower read-write test is used instead of a fast read-only test. .TP +.B \-C " cluster-size" +Specify the size of cluster in bytes. Valid cluster-size values are from +2048 to 256M bytes per cluster. If omiited, cluster-size is 64KB by +default. +.TP .B \-D Use direct I/O when writing to the disk. This avoids mke2fs dirtying a lot of buffer cache memory, which may impact other applications running @@ -516,6 +521,12 @@ prefix the feature name with a caret ('^') character. The pseudo-filesystem feature "none" will clear all filesystem features. .RS 1.2i .TP +.B bigalloc +Allow to allocate block-size beyond the 4096 bytes. That can decrease the time +spent on doing block allocation and brings smaller fragmentation, especially +for large files. The size can be specified using the +.B \-C option. +.TP .B dir_index Use hashed b-trees to speed up lookups in large directories. .TP -- 1.7.12.rc2.18.g61b472e