Bug 1146017

When converting windows guests from xen server using -v -x option,virt-v2v will also hang.

I wonder if /tmp is running out of disk space.  That causes qemu
to hang (see bug 745576).

The root cause of this is that we shouldn't be putting the overlay
on /tmp.  It should go on /var/tmp (or even better, guestfs_get_cachedir).
So I have added this patch:

https://github.com/libguestfs/libguestfs/commit/9a9d10d2a0388f84ace3454c56071c544a3b923f

(Will appear in virt-v2v >= 1.27.55)

(In reply to Richard W.M. Jones from comment #5)
> I wonder if /tmp is running out of disk space.  That causes qemu
> to hang (see bug 745576).

I rerun command (for details see this link:https://bugzilla.redhat.com/show_bug.cgi?id=1145916#c10 )

# virt-v2v -ic xen+ssh://10.66.106.64 -os default xen-hvm-win7-x86_64 -of qcow2 -v -x |& tee xen-hvm-win7-x86_64.log

virt-v2v command hangs at:
hivex: hivex_open: used block id 76,0 (L.) at 0x1966fc0 size 48
hivex: hivex_open: used block id 168,95 (._) at 0x1966ff0 size 16
hivex: hive

file xen-hvm-win7-x86_64.log locates in /root, while hanging check the /root space, enough left.
# df -h /root/
Filesystem      Size  Used Avail Use% Mounted on
/dev/sda6        98G   77G   22G  79% /

Right, but specifically I need to know if */tmp* is running out
of space.  That is where the overlay is stored (or was in < 1.27.55,
in >= 1.27.55 it has moved to /var/tmp).

(In reply to Richard W.M. Jones from comment #7)
> Right, but specifically I need to know if */tmp* is running out
> of space.  That is where the overlay is stored (or was in < 1.27.55,
> in >= 1.27.55 it has moved to /var/tmp).

while hanging, check host:

# df -h /tmp/
Filesystem      Size  Used Avail Use% Mounted on
/dev/sda6        98G   77G   21G  79% /

# df -h 
Filesystem      Size  Used Avail Use% Mounted on
/dev/sda6        98G   77G   21G  79% /
devtmpfs        3.8G     0  3.8G   0% /dev
tmpfs           3.9G  140K  3.9G   1% /dev/shm
tmpfs           3.9G  9.0M  3.8G   1% /run
tmpfs           3.9G     0  3.9G   0% /sys/fs/cgroup

I don't think it will necessarily help, but please try
libguestfs-1.27.55-1.1.el7

I can reproduce it as bug description.
Then try to verify it with new build:
libguestfs-1.27.55-1.1.el7.x86_64
virt-v2v-1.27.55-1.1.el7.x86_64
qemu-kvm-rhev-2.1.2-1.rwmj1.el7.x86_64

steps:
#  virt-v2v -ic xen+ssh://10.66.106.64 -os default   xen-hvm-win7-x86_64 -of qcow2  -on xen-hvm-win7-x86_64-third  -v -x |& tee /tmp/newtracing.log
[   0.0] Opening the source -i libvirt -ic xen+ssh://10.66.106.64 xen-hvm-win7-x86_64
libvirt xml is:
<domain type='xen'>
  <name>xen-hvm-win7-x86_64</name>
  <uuid>a0e13e6b-96a2-ba79-b290-88dfd7d64306</uuid>
  <memory>524288</memory>
  <currentMemory>524288</currentMemory>
  <vcpu>1</vcpu>
  <os>
....
qemu-img convert -p -n -f qcow2 -O 'qcow2' '/var/tmp/v2vovlb8a132.qcow2' '/var/lib/libvirt/images/xen-hvm-win7-x86_64-third-sda'
    (100.00/100%)
[ 384.0] Creating output metadata
Pool default refreshed

Domain xen-hvm-win7-x86_64-third defined from /tmp/v2vlibvirt9a7300.xml

[ 384.0] Finishing off

Result: conversion finished successfully and without hanging，so move this bug to VERIFIED.

Since the problem described in this bug report should be
resolved in a recent advisory, it has been closed with a
resolution of ERRATA.

For information on the advisory, and where to find the updated
files, follow the link below.

If the solution does not work for you, open a new bug report.

https://rhn.redhat.com/errata/RHBA-2015-0303.html