How to label a GELI device
listreader at lazlarlyricon.com
Tue Jan 25 14:29:48 UTC 2011
2011-01-25 15:07, J. Porter Clark skrev:
> On Tue, Jan 25, 2011 at 10:45:52AM +0200, Nikos Vassiliadis wrote:
>> J. Porter Clark wrote:
>>> I have an encrypted partition, /dev/da0s1d. I can use geli
>>> attach da0s1d and obtain a device /dev/da0s1d.eli, which is a
>>> UFS filesystem. All that works just fine.
>>> I'd like to label /dev/da0s1d so that I don't have to refer to
>>> the exact drive number, etc., which might change if I reboot
>>> with a USB stick in the system or whatever. But glabel puts the
>>> label in the last sector, which is where GELI stores metadata.
>> You don't have to worry about this. geli uses the last sector for
>> its metadata and creates a device with one sector less to its clients.
>> The original device is 2048 sectors, the device geli provides is 2047
>>> moby# diskinfo /dev/md0 /dev/md0.eli
>>> /dev/md0 512 1048576 2048 0 0
>>> /dev/md0.eli 512 1048064 2047 0 0
>> There is no way for the "internal" GEOM to mess with the "external's"
> That's fine, but I want to label the "external" /dev/md0, not
> the "internal" /dev/md0.eli.
> What I eventually want to do is to "geli attach" the device
> using a name that doesn't depend on drive numbering.
Correct me if I'm wrong anyone.
You need to first label da0s1d
e.g. like so
glabel label data da0s1d
then geli init the labeled device
e.g. like so
geli init -l 256 -s 4096 label/data
geli attach label/data
That will give you a device node called /dev/label/data.eli, that you
can newfs and mount. Unfortunately, since you already encrypted da0s1d,
you may have to back it up, and restore the data after you've redone it.
I had this problem a few years ago, and I had to back up and restore,
but perhaps it's been made simpler now? Though I doubt it.
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