--- util-linux-2.11f/disk-utils/raw.8.sopwith Tue Feb 26 13:15:34 2002 +++ util-linux-2.11f/disk-utils/raw.8 Tue Feb 26 13:16:28 2002 @@ -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 @@ -58,6 +58,11 @@ disk, they must be an exact number of sectors long, and the data buffer in virtual memory must also be aligned to a multiple of the sector size. The sector size is 512 bytes for most devices. +.PP +Use the /etc/sysconfig/rawdevices file to define the set of raw device +mappings automatically created during the system startup sequence. The +format of the file is the same used in the command line with the exception +that the "raw" command itself is omitted. .SH OPTIONS .TP .B -q @@ -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