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| author | Karel Zak | 2007-01-25 11:22:42 +0100 |
|---|---|---|
| committer | Karel Zak | 2007-01-25 11:22:42 +0100 |
| commit | 69616d88d47f51147480a64962f1fed91f9b8732 (patch) | |
| tree | cd161142232f9de876f0a26cefd714b71fb0c6a0 /disk-utils/raw.8 | |
| parent | hexdump: don't use memset with zero lenght (diff) | |
| download | kernel-qcow2-util-linux-69616d88d47f51147480a64962f1fed91f9b8732.tar.gz kernel-qcow2-util-linux-69616d88d47f51147480a64962f1fed91f9b8732.tar.xz kernel-qcow2-util-linux-69616d88d47f51147480a64962f1fed91f9b8732.zip | |
raw: update man page (about dd and O_DIRECT)
Signed-off-by: Karel Zak <kzak@redhat.com>
Diffstat (limited to 'disk-utils/raw.8')
| -rw-r--r-- | disk-utils/raw.8 | 13 |
1 files changed, 10 insertions, 3 deletions
diff --git a/disk-utils/raw.8 b/disk-utils/raw.8 index 6fbdb8558..dbd44e7b2 100644 --- a/disk-utils/raw.8 +++ b/disk-utils/raw.8 @@ -15,6 +15,11 @@ raw \- bind a Linux raw character device .PP .B raw .B \-qa +.SH WARNING +The rawio is a deprecated interface since Linux kernel 2.6.3. Please, +modify your application to open the block device with the +O_DIRECT flag. + .SH DESCRIPTION .B raw is used to bind a Linux raw character device to a block device. Any @@ -75,10 +80,12 @@ With .B -h provides a usage summary. .SH BUGS -The Linux +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 |