[dm-devel] Re: [PATCH 7/9] scsi_dh: Add support for SDEV_PASSIVE

[Matthew Wilcox]

On Mon, Feb 11, 2008 at 10:27:46AM -0800, Chandra Seetharaman wrote:
> On Sat, 2008-02-09 at 05:45 -0700, Matthew Wilcox wrote:
> > On Mon, Feb 04, 2008 at 01:19:30PM -0800, Chandra Seetharaman wrote:
> > > The device does send these error messages currently, but it takes some
> > > time to get the check condition back, which adds up the time to boot
> > > especially when the # of LUNS is huge.
> > > 
> > > For example, in my test configuration, I had 40 luns, and the time
> > > difference (with this patch and without it) to boot is 171 seconds and
> > > 1426 seconds.
> > 
> > Was that with sync or async SCSI bus scanning?
> 
> I didn't change anything, IOW, i did default scanning, which I would
> guess sync ?!

That would depend on your CONFIG_SCSI_SCAN_ASYNC setting.

Try booting with 'scsi_mod.scan=async' and without this patch, and see
how long it takes.

-- 
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"Bill, look, we understand that you're interested in selling us this
operating system, but compare it to ours.  We can't possibly take such
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