partinfo: Fix usage message

[tools/e2fsprogs.git] / misc / mke2fs.8.in

diff --git a/misc/mke2fs.8.in b/misc/mke2fs.8.in
index 1e9a203..dc35549 100644 (file)
--- a/misc/mke2fs.8.in
+++ b/misc/mke2fs.8.in
@@ -26,6 +26,10 @@ mke2fs \- create an ext2/ext3 filesystem
 .I blocks-per-group
 ]
 [
+.B \-G
+.I number-of-groups
+]
+[
 .B \-i
 .I bytes-per-inode
 ]
@@ -187,8 +191,9 @@ following extended options are supported:
 Configure the filesystem for a RAID array with
 .I stride-size
 filesystem blocks. This is the number of blocks read or written to disk
-before moving to next disk. This mostly affects placement of filesystem
-metadata like bitmaps at
+before moving to next disk, which is sometimes referred to as the 
+.I chunk size.
+This mostly affects placement of filesystem metadata like bitmaps at
 .B mke2fs
 time to avoid placing them on a single disk, which can hurt the performanace.
 It may also be used by block allocator.
@@ -197,7 +202,8 @@ It may also be used by block allocator.
 Configure the filesystem for a RAID array with
 .I stripe-width
 filesystem blocks per stripe. This is typically be stride-size * N, where
-N is the number of data disks in the RAID (e.g. RAID 5 N+1, RAID 6 N+2).
+N is the number of data-bearing disks in the RAID (e.g. for RAID 5 there is one
+parity disk so N will be the number of disks in the array minus 1).
 This allows the block allocator to prevent read-modify-write of the
 parity in a RAID stripe if possible when the data is written.
 .TP
@@ -205,14 +211,15 @@ parity in a RAID stripe if possible when the data is written.
 Reserve enough space so that the block group descriptor table can grow
 to support a filesystem that has max-online-resize blocks.
 .TP
-.B lazy_itable_init= \fI<0 to disable, 1 to enable>
+.B lazy_itable_init\fR[\fb= \fI<0 to disable, 1 to enable>\fR]
 If enabled and the uninit_bg feature is enabled, the inode table will
 not fully initialized by 
 .BR mke2fs .
 This speeds up filesystem
 initialization noitceably, but it requires the kernel to finish
 initializing the filesystem in the background when the filesystem is
-first mounted.
+first mounted.  If the option value is omitted, it defaults to 1 to
+enable lazy inode table initialization.
 .TP
 .B test_fs
 Set a flag in the filesystem superblock indicating that it may be
@@ -245,6 +252,13 @@ option rather than manipulating the number of blocks per group.)
 This option is generally used by developers who
 are developing test cases.  
 .TP
+.BI \-G " number-of-groups"
+Specify the number of block goups that will be packed together to
+create one large virtual block group on an ext4 filesystem.  This
+improves meta-data locality and performance on meta-data heavy
+workloads.  The number of goups must be a power of 2 and may only be
+specified if the flex_bg filesystem feature is enabled.
+.TP
 .BI \-i " bytes-per-inode"
 Specify the bytes/inode ratio. 
 .B mke2fs
@@ -445,6 +459,11 @@ Use hashed b-trees to speed up lookups in large directories.
 .B filetype
 Store file type information in directory entries.
 .TP
+.B flex_bg
+Allow bitmaps and inode tables for a block group to be placed anywhere
+on the storage media (use with -G option to group meta-data in order
+to create a large virtual block group).
+.TP
 .B has_journal
 Create an ext3 journal (as if using the
 .B \-j