Re: [Xen-devel] can't boot from iso on cifs mount

[Ian Campbell <Ian.Campbell@xxxxxxxxxx>]

Please don't top post.

On Tue, 2013-01-22 at 05:38 +0000, Vasiliy Tolstov wrote:
> Thanks!
> I found, that now xl tries to open iso with O_DIRECT flag.
> open("/var/storage/iso/SW_DVD5_Windows_Svr_DC_EE_SE_Web_2008_R2_64Bit_Russian_w_SP1_MLF_X17-22616_vase.iso",
> O_RDONLY|O_DIRECT) = -1 EINVAL (Invalid argument)
> write(2, "qemu: could not open vbd '/local"..., 217) = 217

I guess CIFS doesn't support O_DIRECT. It looks like it does have mount
-o directio though, worth a try.

I'm not sure what options exist to turn this off from the qemu side --
Stefano? I also have a feeling something changed in this regard in 4.2.x

> my xen version is 4.1.3
> 
> 
> 2013/1/21 Ian Campbell <Ian.Campbell@xxxxxxxxxx>:
> > On Sat, 2013-01-19 at 11:23 +0000, Vasiliy Tolstov wrote:
> >> After switching from xm to xl
> >
> > Which version of Xen?
> >
> >>  i found that all my windows hvm domU
> >> can't boot from iso. domU can't boot is iso on cifs mount point. If
> >> that iso move from cifs to ramdisk - all work's fine.
> >>
> >> cifs mount:
> >> //cc/public on /var/storage type cifs
> >> (rw,relatime,vers=1.0,sec=ntlm,cache=none,unc=\\cc\public,uid=0,noforceuid,gid=0,noforcegid,addr=192.168.25.254,unix,posixpaths,serverino,acl,rsize=1048576,wsize=65536,actimeo=1)
> >>
> >> xl messages contains:
> >> Using file /dev/disk/vbd/21-822 in read-write mode
> >> Strip off blktap sub-type prefix to
> >> /var/storage/iso/SW_DVD5_Windows_Svr_DC_EE_SE_Web_2008_R2_64Bit_Russian_w_SP1_MLF_X17-22616_vase.iso
> >> (drv 'aio')
> >> Using file 
> >> /var/storage/iso/SW_DVD5_Windows_Svr_DC_EE_SE_Web_2008_R2_64Bit_Russian_w_SP1_MLF_X17-22616_vase.iso
> >> in read-only mode
> >> qemu: could not open vbd '/local/domain/0/backend/qdisk/162/5632/mode'
> >> or hard disk image
> >> '/var/storage/iso/SW_DVD5_Windows_Svr_DC_EE_SE_Web_2008_R2_64Bit_Ru
> >> ssian_w_SP1_MLF_X17-22616_vase.iso' (drv 'aio' format 'raw')
> >>
> >> domain started with xl create /etc/empty \
> >> -d \
> >> name="21-10824" \
> >> kernel="/usr/lib/xen/boot/hvmloader" \
> >> builder="hvm" \
> >> memory=768 \
> >> vcpus=4 \
> >> vif=["mac=00:16:3e:00:1a:e4,ip=62.76.190.208,type=paravirtualised"]
> >> disk=["phy:/dev/disk/vbd/21-822,hda,w",
> >> "file:/var/storage/iso/SW_DVD5_Windows_Svr_DC_EE_SE_Web_2008_R2_64Bit_Russian_w_SP1_MLF_X17-22616_vase.iso,hdc:cdrom,r",
> >> "file:/var/storage/iso/winpe_amd64.iso,hdb,r,devtype=cdrom"] \
> >
> > If you remove the first CD-ROM entry does the second one work? I expect
> > not (they both parse to the same sort of thing) and it is just failing
> > at the first and not even trying the second.
> >
> > Can you read the .iso manually (e.g. using md5sum or od or something) as
> > root on the dom0? (I'm wondering if there is some CIFS equivalent of
> > root_squash)
> >
> > Do you get anything in /var/log/xen/qemu-dm* in addition to the xl logs?
> >
> > One approach to debugging this might be to use
> >         device_model_override="/path/to/my-qemu"
> > where my-qemu is a script which runs
> >         strace -o /tmp/qemu.strace -fff /usr/lib/xen/bin/qemu-dm $@
> >
> > The strace might tell you a little bit more about how/why it is failing
> > to open the file.
> >
> > Ian.
> >
> 
> 
> 



_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxx
http://lists.xen.org/xen-devel