On Mon, May 8, 2017 at 10:32 AM, John Snow <js...@redhat.com> wrote: > > > On 05/08/2017 10:15 AM, Carl Karsten wrote: > > On Mon, May 8, 2017 at 3:51 AM, Markus Armbruster <arm...@redhat.com> > wrote: > > > >> Carl Karsten <c...@personnelware.com> writes: > >> > >>> juser@gator:~/temp$ qemu-system-x86_64 -m 256 -display curses -drive > >>> file=disk.cow -drive file=boot.img > >>> WARNING: Image format was not specified for 'boot.img' and probing > >> guessed > >>> raw. > >>> Automatically detecting the format is dangerous for raw > images, > >>> write operations on block 0 will be restricted. > >>> Specify the 'raw' format explicitly to remove the > restrictions. > >>> > >>> This is OK, as I don't want anything writing to that thing anyway. So > to > >>> get rid of the waring: > >>> > >>> juser@gator:~/temp$ qemu-system-x86_64 -drive > >>> file=boot.img,format=raw,readonly qemu-system-x86_64: Can't use a > >> read-only > >>> drive > >>> qemu-system-x86_64: Initialization of device ide-hd failed: Device > >>> initialization failed. > >> > >> -drive without if=... creates an IDE disk[*]. IDE disks can't do > >> read-only. Have you tried omitting ",readonly"? > >> > > > > > > omitting works, but my goal was for the drive to be read only. > > > > > > I don't think there's a way to make physical IDE drives "read only." I > don't think there's any jumper settings or any of the like which can > accomplish this. > > Unlike floppy disks (which you could notch the corner of) or SD cards > (which have the write lock), I don't think ATA disks have a method for > being "read only," so this isn't a feature QEMU can support. > > What you CAN do, however, is to use -snapshot or otherwise use something > like a qcow2 overlay to trap all writes to a temporary file that you can > discard at a later point in time, effectively keeping your original > image "read only." > > I believe that SCSI disks support a read-only mode, though. >
k - that all makes sense. kinda ;) "write operations on block 0 will be restricted." Is there a way to explicitly enable that? The installer on the usb stick keeps stepping on itself rendering it broken, both physical usb drive and a dd image. I can play with OS permissions too, but that restricted warning made me think that would be 'best'. but but, now that I have index/bootindex working I probably won't be trashing my installer any more, so non-issue. -- Carl K
