Re: Force device node link creation
On Fri 07 Feb 2020 at 08:40:47 (+0100), Christoph Pleger wrote:
> On 2020-02-06 19:47, David Wright wrote:
> > On Thu 06 Feb 2020 at 17:56:00 (+0100), Christoph Pleger wrote:
> > >
> > > I am using a program for automatic creation of a harddisk partitioning
> > > from a configuration file. That file contains device names like
> > > /dev/sda1 etc. for naming the partitions. After the partitioning has
> > > been completed, I want to create an appropriate fstab from the
> > > configuration file and during that step, want to convert partition
> > > device name entries to entries in the form UUID=... For that, I am
> > > using
> > >
> > > udevadm info --query=symlink --name="$device"
> > >
> > > where $device is the respective partition. Unfortunaly, the problem
> > > occurs that often - though partitioning was completed and filesystems
> > > created - links in /dev/disk/by-uuid/ are not yet available when
> > > udevadm is run, so that udevadm returns nothing. So, my question is:
> > > Is it possible to force the device node links to have been created
> > > before calling udevadm? Without long sleeps or sleep loops?
> >
> > I've only used events after I've done something, like plugging in a
> > stick. Might udevadm trigger … help? I would try it out with,
> > say, udevadm monitor -u -p -s block running.
>
> I have already tried udevadm trigger together with udevadm settle, but
> it did not help. Though it seemed to be the solution till Debian 9
> inclusively.
I'm perplexed by the delay in creating the links. Is that the fault of
the kernel rereading the new partition table, or of udev waking up?
If it's the kernel, might the command Thomas Schmitt mentioned in
another thread be useful
hdparm -z /dev/sdX
for giving it a prod?
Cheers,
David.
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