/dev/ links disappearing

Daryl Sayers darylXYZ at ci.com.au
Fri Nov 24 02:20:31 UTC 2006

>> I am running ubuntu 6.06 after upgrading from and OLD Debian system. I
>> have noticed that my computer thinks it now know better than me. I put
>> a few symlinks into /dev/ to point to generic names like /dev/backup which
>> points to a tape device. Also things like a serial port I have called
>> /dev/modem that points to /dev/ttyS0. Problem is that these symlinks keep
>> disappearing. I am not sure what is cleaning them up. I am sure this has
>> something to do with udevd but I am unable to find any info on what I need
>> to do.

> OK, /dev is entirely virtual, so you can't create links on the "filesystem"
> and expect them to survive a reboot.

> Basically you have to modify rules in /etc/udev/rules.d/.  Look
> at /etc/udev/rules.d/60-symlinks.rules (at least in edgy - otherwise look
> at any .rules files anywhere under /etc/udev to get an idea).

> You can create your own 50-local.rules and add rules like:
> KERNEL="ttyS0", SYMLINK+="modem"
> KERNEL="xxxx", SYMLINK+="backup" 
> (where 'xxxx' is the device name of your tape device).  Note, I already have
> a default entry for ttyLTM[0-9]* in 60-symlinks.rules that sets /dev/modem,
> so you would definitely need your local rules to execute before that - the
> first such allocation of symlink name wins iirc.

Thanks Derek,
This not only pointed me in the right direction it also dotted the i's and
crossed the T's. All working now.

Daryl Sayers
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