util-linux/util-linux-2.12a-raw-man-dd...

29 lines
1.1 KiB
Diff

--- util-linux-2.12a/disk-utils/raw.8.dd 2006-04-24 15:27:39.000000000 +0200
+++ util-linux-2.12a/disk-utils/raw.8 2006-04-24 15:53:46.000000000 +0200
@@ -15,6 +15,12 @@
.PP
.B raw
.B \-qa
+.SH WARNING
+Although Linux includes support for rawio, it is now a deprecated interface. If
+your application performs device access using this interface, Red Hat
+encourages you to modify your application to open the block device with the
+O_DIRECT flag. The rawio interface is a candidate for removal from future releases.
+
.SH DESCRIPTION
.B raw
is used to bind a Linux raw character device to a block device. Any
@@ -82,8 +88,10 @@
.SH BUGS
The Linux
.B dd
-(1) command does not currently align its buffers correctly, and so
-cannot be used on raw devices.
+(1) command should be used without bs= option or the blocksize needs to be a
+multiple of the sector size of the device (512 bytes usually) otherwise it
+will fail with "Invalid Argument" messages (EINVAL).
+
.PP
Raw I/O devices do not maintain cache coherency with the Linux block
device buffer cache. If you use raw I/O to overwrite data already in