> Playing with a mainline PVM kernel, I was trying to determine
> whether a virtual device is a cd/dvd. What do I mean?
>
> - A scsi disk has /sys/block/<name>/device/type. If that contains
''0'',
> it''s a hard disk. If not, it''s something else
(cd/tape/etc). This
> includes SATA, iSCSI, etc. Anything using sd.c.
> - An IDE disk has /sys/block/<name>/device/media. If that contains
> ''disk'' it''s a disk. It can also contain
''cdrom'', ''tape'', etc. This
> used to live at /proc/ide/<name>/media.
>
> How do I determine this for xvdX devices?
> /sys/block/xvda/device has "devtype", but does it contain
''vbd'' for
> cdroms as well? Every example I see online suggests using hdc (IDE) for
> cdroms still - will cdroms stay IDE? Should I assume that xvd devices
> are hard disks always and forever?
Pretty much.
I don''t think PV block devices can support most / any of the special
functionality required to make them really behave like CD-ROM drives from the
guest''s point of view. It is possible to export a CD-ROM drive from
the host
through a PV block device but the CD-ROM specific behaviour will not be
passed through.
I''ve seen greater CD-ROM support for PV block devices stated as a TODO
occasionally but I don''t know of anyone working on it.
CD-ROMs can be more fully emulated for HVM guests, which will know they have
an IDE CD-ROM drive.
Cheers,
Mark
--
Push Me Pull You - Distributed SCM tool (http://www.cl.cam.ac.uk/~maw48/pmpu/)
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