$guestfish -N fs:xfs -m /dev/sda1 statvfs /

libguestfs: error: mkfs: xfs: /dev/sda1: mkfs.xfs: No such file or directory
guestfish: error creating prepared disk image 'fs:xfs' on 'test1.img': failed to create filesystem (xfs): mkfs: xfs: /dev/sda1: mkfs.xfs: No such file or directory

does I need to rebuild the iniramfs to include mkfs.xfs, is this the root reason that cause the different numbers ?

At 2018-01-05 00:22:46, "Richard W.M. Jones" <rjones@redhat.com> wrote:
>To summarise:
>
>>[In guest]
>> python -c 'import os; s = os.statvfs ("/boot"); print s'
>> posix.statvfs_result(f_bsize=4096, f_frsize=4096, f_blocks=127147,
>> f_bfree=93815, f_bavail=93815, f_files=512000, f_ffree=511626,
>> f_favail=511626, f_flag=4096, f_namemax=255)
>
>>[From the host via libguestfs]
>> # sudo guestfish --ro -d rpm-build-for-7.2 -i statvfs /boot
>> bsize: 4096
>> frsize: 4096
>> blocks: 127147
>> bfree: 100215
>> bavail: 100215
>> files: 512000
>> ffree: 511626
>> favail: 511626
>> fsid: 2049
>> flag: 4097
>> namemax: 255
>
>[In virt-rescue]
>> Block size: 4096       Fundamental block size: 4096
>> Blocks: Total: 127147     Free: 93815      Available: 93815
>> Inodes: Total: 512000     Free: 511626
>
>The block stats are the same as the "in guest" results above,
>but slightly different from libguestfs.
>
>		- * - * - * -
>
>I wanted to see if I could reproduce this with a very simple and
>reproducible example.  I made the assumption that this guest is using XFS.
>
>(1) Make an XFS filesystem and use libguestfs to query the statvfs:
>
>$ guestfish -N fs:xfs -m /dev/sda1 statvfs /
>bsize: 4096
>frsize: 4096
>blocks: 24713
>bfree: 23347
>bavail: 23347
>files: 51136
>ffree: 51133
>favail: 51133
>fsid: 2049
>flag: 4096
>namemax: 255
>
>(2) Open the same disk image in virt-rescue and examine with stat
>command:
>
>$ virt-rescue -a test1.img
>><rescue> mount /dev/sda1 /sysroot
>><rescue> stat -f /sysroot
>  File: "/sysroot"
>    ID: 80100000000 Namelen: 255     Type: xfs
>Block size: 4096       Fundamental block size: 4096
>Blocks: Total: 24713      Free: 23347      Available: 23347
>Inodes: Total: 51136      Free: 51133
>
>
>In this case the numbers are the same ...
>
>I would really like a bit more information though:
>
>(a) Are you using XFS or another filesystem?
>
>(b) Can you make a small independent reproducer like mine above?
>
>Rich.
>
>-- 
>Richard Jones, Virtualization Group, Red Hat http://people.redhat.com/~rjones
>Read my programming and virtualization blog: http://rwmj.wordpress.com
>libguestfs lets you edit virtual machines.  Supports shell scripting,
>bindings from many languages.  http://libguestfs.org