Change in udev

[Gary Thomas <gary@mlbassoc.com>]

I know that udev is being replaced by eudev, but there's a new
behavior I don't understand.  There is a new file /etc/udev/hwdb.bin
that is created at runtime:

$ ls -l /etc/udev
total 6548
-rw-r--r-- 1 root root    1785 Jan  9  1970 cache.data
-r--r--r-- 1 root root 6660476 Mar 24 08:21 hwdb.bin
drwxr-xr-x 2 root root    4096 Mar 24 06:42 hwdb.d
-rw-r--r-- 1 root root      51 Mar 24 07:51 mount.blacklist
drwxr-xr-x 2 root root    4096 Mar 24 07:51 mount.blacklist.d
drwxr-xr-x 2 root root    4096 Mar 24 08:21 rules.d
drwxr-xr-x 2 root root    4096 Mar 24 07:51 scripts
-rw-r--r-- 1 root root      49 Mar 24 06:41 udev.conf

Is this [somehow] equivalent to the old udev device cache?
Does it really belong in /etc/udev?  What about read-only roots?

Thanks

n.b. I just noticed because a dump of /etc on my device went
from ~6MB to over 12MB...

-- 
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Gary Thomas                 |  Consulting for the
MLB Associates              |    Embedded world
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