Date: Fri, 17 Sep 2004 16:27:31 -0400
From: Valdis.Kletnieks@xxxxxx
To: Eric Mudama <edmudama@xxxxxxxxx>
Cc: David Stevens <dlstevens@xxxxxxxxxx>, Netdev <netdev@xxxxxxxxxxx>,
leonid.grossman@xxxxxxxx, Linux Kernel <linux-kernel@xxxxxxxxxxxxxxx>
Subject: Re: The ultimate TOE design
On Fri, 17 Sep 2004 00:46:59 MDT, Eric Mudama said:On Wed, 15 Sep 2004 14:11:04 -0600, David Stevens <dlstevens@xxxxxxxxxx> wrote:Why don't we off-load filesystems to disks instead?
Disks have had file systems on them since close to the beginning...
No, he means "offload the processing of the filesystem to the disk itself".
IBM's MVS systems basically did that - it used the disk's "Search Key" I/O
opcodes to basically get the equivalent of doing namei() out on the disk itself
(it did this for system catalog and PDS directory searches from the beginning,
and added 'indexed VTOC' support in the mid-80s). So you'd send out a CCW
(channel command word) stream that basically said "Find me the dataset
USER3.ACCTING.TESTJOBS", and when the I/O completed, you'd have the DSCB (the
moral equiv of an inode) ready to go.