Re: Booting iso files (loopback) on btrfs partitions

[Goh Lip]

On 08/28/2011 03:35 AM, Jordan Uggla wrote:
> On Thu, Aug 25, 2011 at 4:59 PM, Goh Lip<address@hidden>  wrote:
> > Using grub 1.99, have failed to boot iso files (loopback, casper) when
> > located in btrfs partitions. Have tried setting search to uuid, label, file
> > and using (hdx,y) instead too. All failed to boot.
>
> Failed to boot how? What error message do you see? If you run "ls -l"
> at the grub shell do you see the btrfs filesystem listed? If you try
> running each command separately at the grub shell (loopback, linux,
> initrd, boot) do any of them fail?



############################### START ################################

grub> ls
(hd0), (hd0,msdos11),.........(hd0,msdos1)
grub> ls (hd0)
Device hd0 - Not a known filesystem -Total size 488397168
grub> ls (hd0,1)
Partition hd0,1 : Filesystem type btrfs - Label "Uno", UUID 
4051bc43-1b86-4f34-ad0d-ef731ed2c376 - Partition starts at 2048 - Total 
size 81920000 sectors

grub> insmod part_msdos
grub> insmod btrfs
grub> set isofile="/uiso/pod0.iso"
grub> search --no-floppy --file --set=root $isofile
grub> loopback loop $isofile
grub> linux (loop)/casper/vmlinuz boot=casper iso-scan/filename=$isofile 
nopersistent noeject noprompt quiet splash
grub> initrd (loop)/casper/initrd.gz
grub> boot

[no output or error message before last 'boot' command]


stdin : error 0

/scripts/casper-premount/20iso-scan: line 46 : can't open dev/sr0 :No 
medium found.



Busybox v1.1.13.3(Ubuntu 1:1.13.3-1ubuntu11) built-in shell(sh)
Enter 'help' for a list of built-in commands

(initramfs)      stdin: error 0
/scripts/casper-premount/20iso-scan: line 46 : can't open dev/sr0 :No 
medium found.
Could not find the the ISO /uiso/pod0.iso. This could also happen if the 
file system is not clean because of an operating system crash, an 
interrupted boot process, an improper shutdown, or unplugging of a 
removable device without first unmounting or ejecting it. To fix this, 
simply reboot into Windows, let it fully start, log in, run 'chkdsk /r', 
then gracefully shut down and reboot back into Windows. After this, you 
should be able to reboot again and resume the installation.


###############################   END   ################################

o file above is remastered and initrd is initrd.gz not initrd.lz
o using usual livecd file (initrd.lz) gives same results as above
o moved file/s to another btrfs partition with another directory name 
gives similar results.

As stated on earlier post,
o booting using same instructions to same files located in ext4 
partitions boot successfully. [note]
o used different search parameters (uuid, label, (hd0,1)/sda1) result in 
similar boot failures as above.

[note] on successful boots of ext4 files
       - stdin : error 0                                *is* there
         /scripts/casper-premount/20iso-scan: line 46   *not* there


Regards and thanks - Goh Lip