Re: [PATCH 1/3] Add virtioblk_id tool to extract drive serial numbers

[Ryan Harper <ryanh@us.ibm.com>]

* Kay Sievers <kay.sievers@vrfy.org> [2010-06-03 15:06]:
> On Thu, Jun 3, 2010 at 22:01, Ryan Harper <ryanh@us.ibm.com> wrote:
> > * Kay Sievers <kay.sievers@vrfy.org> [2010-06-03 14:53]:
> >> On Thu, Jun 3, 2010 at 21:07, Ryan Harper <ryanh@us.ibm.com> wrote:
> >> > Use the 'VBID' virtio-blk ioctl to extract drive serial numbers
> >> > to be used for building disk/by-id symlinks.  After extracting
> >> > the serial number of the device it prints out the minimum info
> >> > needed in a similar format to `scsi_id --export` so that the
> >> > persistent-storage rules can process the serial information.
> >> >
> >> > This program depends on the virtio-blk serial device patches posted
> >> > here[1] being applied to qemu and linux-kernel.
> >> >
> >> > Here is what the output looks like:
> >> >
> >> > % ./virtioblk_id /dev/vdb
> >> > ID_VIRTIO=1
> >> > ID_TYPE=disk
> >> > ID_VIRTIO_SERIAL=QM00001
> >>
> >> Yikes! An ioctl to copy a plain string, and an entire binary to call
> >> that ioctl and print it. If we don't have enough problems we make new
> >> ones? :)
> >>
> >> What's the reason to drop the ATA identify, that would work out-of-the
> >> box without any of this stuff. It could also support WWN, which is
> >> what people are looking for these days.
> >
> > http://www.mail-archive.com/qemu-devel@nongnu.org/msg24321.html
> >
> > 1. Virtio-blk isn't an ATA device
> > 2. The ATA identify page is too large to fit into the virtio config
> > space
> >
> > I'm not finding the older threads where this was discussed in detail.
> > I'll keep looking if the above isn't a sufficient explaination.
> 
> Well, if ATA doesn't fit, then put that string in sysfs like mmc block
> devices are doing it. It looks really awkward to require a new binary
> and a new ioctl to get a single string out of something that was just
> invented.

John,

you mentioned that you had a sys interface in-mind earlier.  I'm not
sure how to proceed given the virtio-blk kernel side patches are
already upstream[1][2].  Are we looking to revert and switch?


1.  http://repo.or.cz/w/linux-2.6.git/commitdiff/234f2725a5d03f78539f1d36cb32f2c4f9b1822c
2.  http://repo.or.cz/w/linux-2.6.git/commitdiff/4cb2ea28c55cf5e5ef83aec535099ffce3c583df


-- 
Ryan Harper
Software Engineer; Linux Technology Center
IBM Corp., Austin, Tx
ryanh@us.ibm.com