[Vmdebootstrap-devel] Bug#805154: vmdebootstrap: mount image root with nobarrier / huge performance gain

[Florian Lohoff]

Package: vmdebootstrap
Version: 0.5-2
Severity: wishlist

Hi,
when creating an image please consider mounting the ext4
in the image with "nobarrier". I had a quick look at the
code in newer vmdebootstraps but the code mounting
the rootfs from the loopback did not change.

On my example machine this brings down the creation of
the image from 9:47 Min to 1:30 Min. This also solves
the discussions concerning "eatmydata" and debootstrap.

I changed this:

224     def mount(self, device, path=None):
225         if not path:
226             mount_point = self.mkdtemp()
227         else:
228             mount_point = path
229         self.message('Mounting %s on %s' % (device, mount_point))
230         self.runcmd(['mount', '-o', 'nobarrier', device, mount_point])
231         self.mount_points.append(mount_point)
232         logging.debug('mounted %s on %s' % (device, mount_point))
233         return mount_point
234 

Flo

-- System Information:
Debian Release: 8.2
  APT prefers stable-updates
  APT policy: (500, 'stable-updates'), (500, 'stable')
Architecture: amd64 (x86_64)
Foreign Architectures: i386

Kernel: Linux 3.16.0-4-amd64 (SMP w/4 CPU cores)
Locale: LANG=en_US.utf8, LC_CTYPE=en_US.utf8 (charmap=UTF-8)
Shell: /bin/sh linked to /bin/dash
Init: systemd (via /run/systemd/system)

Versions of packages vmdebootstrap depends on:
ii  debootstrap    1.0.67
ii  extlinux       3:6.03+dfsg-5+deb8u1
ii  kpartx         0.5.0-6+deb8u1
ii  parted         3.2-7
ii  python-cliapp  1.20140719-1
pn  python:any     <none>
ii  qemu-utils     1:2.1+dfsg-12+deb8u4

Versions of packages vmdebootstrap recommends:
ii  grub2-common      2.02~beta2-22
ii  qemu-system       1:2.1+dfsg-12+deb8u4
ii  qemu-user-static  1:2.1+dfsg-12+deb8u4
ii  squashfs-tools    1:4.2+20130409-2

vmdebootstrap suggests no packages.

-- no debconf information