Re: [Libguestfs] error invalid partition data while using libguestfs-tools

Many thanks. ------------------&nbsp;Original&nbsp;------------------ From: &nbsp;"Richard W.M. Jones&quot;;&lt;rjones(a)redhat.com&amp;gt;; Send time:&nbsp;Friday, Mar 19, 2021 6:58 PM To:&nbsp;"钱非凡"<b3ale693592@foxmail.com&gt;; Cc:&nbsp;"libguestfs"<libguestfs@redhat.com&gt;; Subject: &nbsp;Re: [Libguestfs] error invalid partition data while using libguestfs-tools On Fri, Mar 19, 2021 at 11:47:09AM +0800, 钱非凡 wrote: &gt; Thanks for replying, rich. &gt; &gt; here are some informations i gathered. the guest is linux (centos) and i find &gt; out the guest's file system is 'xfs' using `df -hT`: &gt; &gt; ``` &gt; $ df -hT &gt; Filesystem&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; Type&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; Size&nbsp; Used Avail Use% Mounted on &gt; /dev/mapper/centos-root xfs&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; 8.0G&nbsp; 1003M&nbsp; 7.1G&nbsp;&nbsp; 13% / &gt; devtmpfs&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; devtmpfs&nbsp; 484M&nbsp;&nbsp;&nbsp;&nbsp; 0&nbsp; 484M&nbsp;&nbsp;&nbsp; 0% /dev &gt; tmpfs&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; tmpfs&nbsp;&nbsp;&nbsp;&nbsp; 496M&nbsp;&nbsp;&nbsp;&nbsp; 0&nbsp; 496M&nbsp;&nbsp;&nbsp; 0% /dev/shm &gt; tmpfs&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; tmpfs&nbsp;&nbsp;&nbsp;&nbsp; 496M&nbsp; 6.8M&nbsp; 489M&nbsp;&nbsp;&nbsp; 2% /run &gt; tmpfs&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; tmpfs&nbsp;&nbsp;&nbsp;&nbsp; 496M&nbsp;&nbsp;&nbsp;&nbsp; 0&nbsp; 496M&nbsp;&nbsp;&nbsp; 0% /sys/fs/cgroup &gt; /dev/vda1&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; xfs&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; 1014M&nbsp; 132M&nbsp; 883M&nbsp;&nbsp; 14% /boot &gt; tmpfs&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; tmpfs&nbsp;&nbsp;&nbsp;&nbsp; 100M&nbsp;&nbsp;&nbsp;&nbsp; 0&nbsp; 100M&nbsp;&nbsp;&nbsp; 0% /run/user/0 &gt; ``` &gt; &gt; and sgdisk version is 0.8.10: &gt; &gt; ``` &gt; $ sgdisk --version &gt; GPT fdisk (sgdisk) version 0.8.10 &gt; ``` &gt; &gt; also, i tried the command you gave. it came out the same output: &gt; &gt; ``` &gt; $ virt-rescue --ro -d 138093b9b33345c38e58efa014036bd8 &gt; &gt;<rescue&gt; sgdisk /dev/sdb -i 1 &gt; Invalid partition data! &gt; ``` Yup, basically sgdisk thinks the partition is invalid.&nbsp; Version 0.8.10 is really ancient - from 2014, so I'd start with a newer version. Rich. &gt; but strange things happened when i tried some other reports' suggestions: &gt; &gt; https://listman.redhat.com/archives/libguestfs/2016-February/msg00145.html &gt; https://listman.redhat.com/archives/libguestfs/2018-November/msg00026.html &gt; &gt; i did these things: &gt; &gt; 1. set LIBGUESTFS_BACKEND to direct; &gt; 2. recompile the `libguestfs-1.40.2-10.el7.src.rpm` without the ` &gt; XXXX-RHEL-7-Reject-use-of-libguestfs-winsupport-features-.patch `; &gt; 3. run the `virt-rescue` command again. &gt; &gt; ``` &gt; $ virt-rescue --ro -d 138093b9b33345c38e58efa014036bd8 &gt; &gt;<rescue&gt; sgdisk /dev/sdb -i 1 &gt; Creating new GPT entries. &gt; Partition #1 does not exist. &gt; ``` &gt; &gt; and the command works somehow. apparently, i still dont understand what &gt; happened indeed. and i have read about the official explanation of &gt; LIBGUESTFS_BACKEND, is this something to do with libvirt? is it a bug or &gt; something? &gt; &gt; https://libguestfs.org/libguestfs-test-tool.1.html# &gt; trying-out-with-without-libvirt It's unlikely that libguestfs or libvirt or the backend has anything to do with this. The partition is corrupt and/or ancient sgdisk has a bug. Rich. -- Richard Jones, Virtualization Group, Red Hat http://people.redhat.com/~rjones Read my programming and virtualization blog: http://rwmj.wordpress.com virt-p2v converts physical machines to virtual machines.&nbsp; Boot with a live CD or over the network (PXE) and turn machines into KVM guests. http://libguestfs.org/virt-v2v