Explain which valid block sizes mke2fs supports in more detail.
Reviewed-by: Andreas Dilger <adilger@xxxxxxxxx>
Signed-off-by: Jan Kara <jack@xxxxxxx>
---
misc/mke2fs.8.in | 10 ++++++----
1 file changed, 6 insertions(+), 4 deletions(-)
diff --git a/misc/mke2fs.8.in b/misc/mke2fs.8.in
index e6bfc6d6fd2d..171315b142bc 100644
--- a/misc/mke2fs.8.in
+++ b/misc/mke2fs.8.in
@@ -207,12 +207,14 @@ manual page for more details.
.SH OPTIONS
.TP
.BI \-b " block-size"
-Specify the size of blocks in bytes. Valid block-size values are 1024,
-2048 and 4096 bytes per block. If omitted,
-block-size is heuristically determined by the filesystem size and
+Specify the size of blocks in bytes. Valid block-size values are powers of two
+from 1024 up to 65536 (however note that the kernel is able to mount only
+filesystems with block-size smaller or equal to the system page size - 4k on
+x86 systems, upto 64k on ppc64 or aarch64 depending on kernel configuration).
+If omitted, block-size is heuristically determined by the filesystem size and
the expected usage of the filesystem (see the
.B \-T
-option). If
+option). In most common cases, the default block size is 4k. If
.I block-size
is preceded by a negative sign ('-'), then
.B mke2fs
--
2.16.4
