Re: [Libguestfs] nbdkit build failure in Koji
On Fri, Jul 31, 2020 at 09:11:51AM -0500, Eric Blake wrote:
Growing a small amount but still being sparse is different from
growing a huge amount to be non-sparse altogether. I'll have to
double-check what the test is actually doing (the size of the files
involved) and see if we can relax the test into allowing a range of
sizes that show a file is still reasonably sparse. But knowing what
filesystem koji is using may matter (for example, if this is
something that shows up on btrfs but not ext4, that would explain
why koji fails when I pass locally...)
So about btrfs: While Fedora is planning to use btrfs for desktop
installs in future, that hasn't happened so far, isn't planned for the
server editions, and I doubt will ever affect Koji because that uses
RHEL. Nevertheless I thought it'd be interesting to try it because I
don't think I've ever used btrfs for this.
$ nbdkit memory 4G allocator=zstd
# modprobe nbd
# nbd-client -b 512 localhost /dev/nbd0
# mkfs.btrfs /dev/nbd0
# mount /dev/nbd0 /tmp/mnt
# chown rjones.users /tmp/mnt
I built nbdkit from git on this filesystem and ran the tests and it
was all fine.
After the tests:
$ stat -f /tmp/mnt
File: "/tmp/mnt"
ID: 842a95913d293347 Namelen: 255 Type: btrfs
Block size: 4096 Fundamental block size: 4096
Blocks: Total: 1048576 Free: 801634 Available: 736710
Inodes: Total: 0 Free: 0
$ df -h /tmp/mnt
Filesystem Size Used Avail Use% Mounted on
/dev/nbd0 4.0G 968M 2.9G 26% /tmp/mnt
Rich.
--
Richard Jones, Virtualization Group, Red Hat http://people.redhat.com/~rjones
Read my programming and virtualization blog: http://rwmj.wordpress.com
virt-df lists disk usage of guests without needing to install any
software inside the virtual machine. Supports Linux and Windows.
http://people.redhat.com/~rjones/virt-df/