Re: dd vs. truncate for creating vkernel root images

["Nuno Antunes" <nuno.antunes@xxxxxxxxx>]

Forgot to copy to users@...

On 4/12/07, Nuno Antunes <nuno.antunes@gmail.com> wrote:
> On 4/12/07, Nuno Antunes <nuno.antunes@gmail.com> wrote:
> > On 4/12/07, Justin C. Sherrill <justin@shiningsilence.com> wrote:
> > > On Wed, April 11, 2007 6:00 pm, Nuno Antunes wrote:
> > > > Hi all,
> > > >
> > > > Is there any advantage in using
> > > > 'dd if=/dev/zero of=/var/vkernel/rootimg.01 bs=1m count=2048'
> > > > over the much quicker
> > > > 'truncate -s 2G /var/vkernel/rootimg.01'
> > > > other than getting a root image filled with zeros?
> > >
> > > Have you tried it?  What happened?
> > >
> > >
> >
> > Yes I have, and it works. Vkernels can use a root image created this
> > way. So does it mean that the file will grow on demand (up to the
> > established size, of course)?
> >
> > Thanks,
> > Nuno
> >
>
> Here are my image sizes:
>
> whitewidow# ll -h /var/vkernel/devel.rootimg.01
> -rw-rw-r--  1 root  wheel   512M Apr 12 00:32 /var/vkernel/devel.rootimg.01
> whitewidow# du -sh /var/vkernel/devel.rootimg.01
> 339M    /var/vkernel/devel.rootimg.01
>
> And inside the vkernel:
> # df -h
> Filesystem   Size   Used  Avail Capacity  Mounted on
> /dev/vkd0a   496M   186M   270M    41%    /
>
> Cheers,
> Nuno