/etc/blkid.tab symlink is broken (or: /dev/.blkid.tab doesn't exist)

[Daniel Richard G.]

Binary package hint: libblkid1

This concerns libblkid1 2.16-1ubuntu5 in Karmic.

    # ls -l /etc/blkid.tab
    lrwxrwxrwx 1 root root 15 2009-11-06 12:38 /etc/blkid.tab -> /dev/.blkid.tab
    # ls -l /dev/.blkid.tab
    ls: cannot access /dev/.blkid.tab: No such file or directory

I see this in systems installed using the regular Ubuntu installer, as well as the alternate installer.

[Scott James Remnant (Canonical) (canonical-scott)]

That's perfectly normal, you haven't run "blkid" yet.

quest scott% ls -l /etc/blkid.tab
lrwxrwxrwx 1 root root 15 2010-03-15 09:29 /etc/blkid.tab -> /dev/.blkid.tab
quest scott% ls -l /dev/.blkid.tab
ls: cannot access /dev/.blkid.tab: No such file or directory

quest scott% sudo blkid
/dev/sda1: UUID="e4637ab5-73a5-40e2-8721-84afd2d79449" TYPE="ext4"
/dev/sda5: UUID="e5f0cf9a-217a-48f0-afc5-4564c34a312e" TYPE="swap"
/dev/sdb1: UUID="74A83B1CA83ADC74" TYPE="ntfs"
quest scott% ls -l /dev/.blkid.tab
-rw-r--r-- 1 root root 328 2010-03-22 17:11 /dev/.blkid.tab

[Daniel Richard G. (skunk)]

The bug is that the system didn't invoke blkid(8) in the first place, whether in the installer or the startup scripts. Are you saying that /etc/blkid.tab should be a dangling symlink until/unless the user manually creates the target? Even many technical users don't know what the blkid(8) command is about.

[Scott James Remnant (Canonical) (canonical-scott)]

On Mon, 2010-03-22 at 23:24 +0000, Daniel Richard G. wrote:

> The bug is that the system didn't invoke blkid(8) in the first place,
> whether in the installer or the startup scripts. Are you saying that
> /etc/blkid.tab should be a dangling symlink until/unless the user
> manually creates the target? Even many technical users don't know what
> the blkid(8) command is about.
>
The system frequently invokes blkid, however it invokes it in "direct
probe" mode and stores the results in the udevdb - which is where all
modern software gets the information.

So it's quite normal for blkid.tab to be a dangling symlink until an
application that hasn't been ported to udev runs blkid (at which point
it's populated)

The reason you don't see one is because most things have switched to
udev

Scott
--
Scott James Remnant
<email address hidden>

[Daniel Richard G. (skunk)]

Okay, that clears things up for me.

Bear in mind that dangling symlinks are noticeable (e.g. if you use the dircolors(1) ORPHAN directive), and seeing one in /etc is usually a sign that something is misconfigured. For now, I'm running blkid(8) on my system images, but I'd like to see the symlink go away completely.