USBVMs based on fedora-23-minimal do not properly pass block devices

[andrewdavidwong]

Qubes OS version (e.g., R3.1):

R3.1

Affected TemplateVMs (e.g., fedora-23, if applicable):

fedora-23-minimal

---

Steps to reproduce the behavior:

1. Create USBVM based on fedora-23-minimal.
2. Create testvm based on fedora-23.
3. Physically plug in USB drive.
4. Use Qubes Manager to attach it to testvm.
5. qvm-block -l claims it's attached to testvm as xvdi.
6. Check testvm. There is no /dev/xvdi.

General notes:

Changing the USBVM from fedora-23-minimal to fedora-23 avoids the problem.

Thread: https://groups.google.com/d/msgid/qubes-users/5743431F.2060607%40vfemail.net

[entr0py]

Is it proper form to cross-post with qubes-users? or is one preferred over the other?

Marek Marczykowski-Górecki:

Check for other xvd* device (for example xvdj). Also you may try xl block-list, especially look at "state" column - should be "4". Normal
AppVM has 4 disks, so 5th should be your usb stick.

xl block-list shows it as state "3"! No sign of it using fdisk (no abnormal xvd*'s)

#Before attaching...
[user@dom0 ~]$ xl block-list appVM 
Vdev  BE  handle state evt-ch ring-ref BE-path                       
51712 0   7      4     17     8        /local/domain/0/backend/vbd/7/51712
51728 0   7      4     18     9        /local/domain/0/backend/vbd/7/51728
51744 0   7      4     19     10       /local/domain/0/backend/vbd/7/51744
51760 0   7      4     20     11       /local/domain/0/backend/vbd/7/51760

# After attaching...
[user@dom0 ~]$ xl block-list appVM
Vdev  BE  handle state evt-ch ring-ref BE-path                       
51712 0   7      4     17     8        /local/domain/0/backend/vbd/7/51712
51728 0   7      4     18     9        /local/domain/0/backend/vbd/7/51728
51744 0   7      4     19     10       /local/domain/0/backend/vbd/7/51744
51760 0   7      4     20     11       /local/domain/0/backend/vbd/7/51760
51840 3   7      3     25     868      /local/domain/3/backend/vbd/7/51840

[entr0py]

Is it proper form to cross-post with qubes-users? or is one preferred over the other?

Marek Marczykowski-Górecki:

Check for other xvd* device (for example xvdj). Also you may try xl block-list, especially look at "state" column - should be "4". Normal
AppVM has 4 disks, so 5th should be your usb stick.

xl block-list shows it as state "3"! No sign of it using fdisk (no abnormal xvd*'s)

#Before attaching...
[user@dom0 ~]$ xl block-list appVM 
Vdev  BE  handle state evt-ch ring-ref BE-path                       
51712 0   7      4     17     8        /local/domain/0/backend/vbd/7/51712
51728 0   7      4     18     9        /local/domain/0/backend/vbd/7/51728
51744 0   7      4     19     10       /local/domain/0/backend/vbd/7/51744
51760 0   7      4     20     11       /local/domain/0/backend/vbd/7/51760

# After attaching...
[user@dom0 ~]$ xl block-list appVM
Vdev  BE  handle state evt-ch ring-ref BE-path                       
51712 0   7      4     17     8        /local/domain/0/backend/vbd/7/51712
51728 0   7      4     18     9        /local/domain/0/backend/vbd/7/51728
51744 0   7      4     19     10       /local/domain/0/backend/vbd/7/51744
51760 0   7      4     20     11       /local/domain/0/backend/vbd/7/51760
51840 3   7      3     25     868      /local/domain/3/backend/vbd/7/51840

[andrewdavidwong]

Is it proper form to cross-post with qubes-users? or is one preferred over the other?

I think it's fine in this case. It depends on the situation.

[andrewdavidwong]

Is it proper form to cross-post with qubes-users? or is one preferred over the other?

I think it's fine in this case. It depends on the situation.

[entr0py]

XenbusStateInitialised = 3, /* Initialised and waiting for a connection from the peer. */

So I've been trying to troubleshoot this issue rather blindly... by comparing fedora-23 template to fedora-23-minimal template:

1. checked qvm-prefs & *.conf files
2. lsmod shows the same modules running on both systems
3. Kernel configs (from /proc/config.gz) have identical checksums.
4. dnf list installed *guess* in both systems to see which packages are missing. Installing missing packages in the minimal template and rebooting have not resolved. "guess" includes, xen, qubes, qvm, bus, virt, virsh, usb, blk, block, qxl, qemu, whatever else I could think of... qubes-template-minimal-stub.spec complicates this but don't see any obvious candidates in there that might resolve this.

Can anyone point me in some kind of direction? Thanks!

[entr0py]

XenbusStateInitialised = 3, /* Initialised and waiting for a connection from the peer. */

So I've been trying to troubleshoot this issue rather blindly... by comparing fedora-23 template to fedora-23-minimal template:

1. checked qvm-prefs & *.conf files
2. lsmod shows the same modules running on both systems
3. Kernel configs (from /proc/config.gz) have identical checksums.
4. dnf list installed *guess* in both systems to see which packages are missing. Installing missing packages in the minimal template and rebooting have not resolved. "guess" includes, xen, qubes, qvm, bus, virt, virsh, usb, blk, block, qxl, qemu, whatever else I could think of... qubes-template-minimal-stub.spec complicates this but don't see any obvious candidates in there that might resolve this.

Can anyone point me in some kind of direction? Thanks!

[marmarek]

Take a look at /var/log/xen/xen-hotplug.log - maybe there you'll find something helpful.

[marmarek]

Take a look at /var/log/xen/xen-hotplug.log - maybe there you'll find something helpful.

[entr0py]

Thank you!

SOLVED! fedora-23-minimal template requires perl to be installed in order to function as a usbVM.

sigh... could live another lifetime with all the hours wasted from not knowing where to look :)

[entr0py]

Thank you!

SOLVED! fedora-23-minimal template requires perl to be installed in order to function as a usbVM.

sigh... could live another lifetime with all the hours wasted from not knowing where to look :)

[andrewdavidwong]

@marmarek, do you want to include perl in fedora-*-minimal templates by default, or instead note in the documentation that the user must install perl in order to use a fedora-*-minimal-based VM as a USB VM?

[andrewdavidwong]

@marmarek, do you want to include perl in fedora-*-minimal templates by default, or instead note in the documentation that the user must install perl in order to use a fedora-*-minimal-based VM as a USB VM?

[marmarek]

If possible, I'd like to not depend on perl for USBVM. But if not, add a documentation about this requirement. It looks like the only perl usage there is in locking mechanism.
I think the whole locking in this script isn't really needed in USBVM (but it is in dom0, and it is the same script). Will think of something...

[marmarek]

If possible, I'd like to not depend on perl for USBVM. But if not, add a documentation about this requirement. It looks like the only perl usage there is in locking mechanism.
I think the whole locking in this script isn't really needed in USBVM (but it is in dom0, and it is the same script). Will think of something...

[ptitdoc]

I will also take a look at it in order to add it as a (optional?) dependency in archlinux.

[ptitdoc]

I will also take a look at it in order to add it as a (optional?) dependency in archlinux.

[unman]

@andrewdavidwong Fedora 23 is eol, and the issue doesn't arise with Fedora24-minimal on r3.2, so I believe this can now be closed.

[unman]

@andrewdavidwong Fedora 23 is eol, and the issue doesn't arise with Fedora24-minimal on r3.2, so I believe this can now be closed.