On Thursday March 7, dstephenson@snapserver.com wrote:
> The release of 0.6 reminded me that I had some changes to mdctl-0.5 I hadn't
> sent on to the list. I added three options to mdctl which I've found to be
> handy. I'm not claiming they will be useful to others, or that they're a
> good idea to add to mdctl. YMMV.
Thanks for this. I'm sure we will find some of it useful.
>
> The first is --analyze or -Z. It's a cross between --detail and --examine
> (from which the code is taken, of course). Given a device, it tries to
> figure out the status of the RAID it is a part of, and its state within the
> RAID, and condense it to a terse one line output. I use it for
> scripting.
I'm having difficulty figuring out exactly what the modivation for
this is, so it's hard to say just what I think of it.
It is almost like a varient of the new
mdctl --examine --scan
The differences being that:
- You only report one array, the one that has the nomiated device.
- You report if the array is active or not
- You report the state of each componenet device.
Possibly the state information could be added to the output of
mdctl --examine --brief
as comments (so that they are syntactically acceptable in the config
file, and if explicit devices are given with
mdctl --examine --scan
then only arrays containing those devices are reported.
Would that work for you?
>
> The second is --assemble-using or -U. It's an --assemble command for the
> lazy. Given a device, it pulls the UUID off it and then uses it for the
> --assemble command. I basically use this to loop through the devices in
> mdctl.conf and start the arrays connected with them automatically at startup
> time. I don't have to keep track of the UUIDs this way.
You needs someway of keeping track of which array is which.
With 0.6, you can use super-minor= if you are sure you wont have drives
imported from other machines, or devices= if you are sure that device
names wont change.
I suspect that with 0.6 an mdctl.conf file like
DEVICES /dev/hd?* /dev/sd?*
array /dev/md0 super-minor=0
array /dev/md1 super-minor=1
array /dev/md2 super-minor=2
array /dev/md3 super-minor=3
array /dev/md4 super-minor=4
array /dev/md5 super-minor=5
would work for you.
You could even try:
echo 'DEVICES /dev/hd?* /dev/sd?*' > /etc/mdctl.conf
mdctl -Es >> /etc/mdctl.conf
mdctl -As
and pick up everything that way.
However if you got any stray devices with raid superblocks coming into
your system, this would fall apart.
>
> Of course, starting up all the RAIDs connnected with the devices in
> mdctl.conf makes it tough to keep a RAID from starting. So the third is
> --destroywithextremeprejudice (no short option for this one). All it does
> is zero out the RAID superblock on a device. It's not smart at all (for
> instance, it should probably make sure the RAID isn't active before it
> zeroes it...). But it is handy for killing stopped RAIDs :->.
I'm pretty happy with this one. I like the lack of a short option.
But I like hyphens between words, and I think that
--destroy-with-extreme-prejudice
is just a little bit too long.
What would you think of:
--erase-superblock
I might put that in and do a 0.6.1.
NeilBrown
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