Hi All, I am trying to create an MD device. I am using the command: /sbin/mdadm --create --a /dev/md12 --level=1 --run --raid-devices=2 /dev/sda12 /dev/sdb12 to create the device, and to dynamically create the device file if needed. What I want is the device file to be created as /dev/md12, but with the -a flag it creates it as /dev/md<first unwsed minor number>.
I have tried various options to the -a or --auto, but cannot seem to find the correct syntax. From the man page it says: -a, --auto{=no,yes,md,mdp,part,p}{NN} Instruct mdadm to create the device file if needed, and to allocate an unused minor number. "yes" or "md" causes a non-partitionable array to be used. "mdp", "part" or "p" causes a partitionable array (2.6 and later) to be used. The argumentment can also come immediately after "-a". e.g. "-ap".
Am I doing something wrong, or is there no way to get mdadm to automatically create a specific device file.
Thanks...
On Nov 2, 2007 8:14 PM, Art Baldini rootajb@gmail.com wrote:
Hi All, I am trying to create an MD device. I am using the command: /sbin/mdadm --create --a /dev/md12 --level=1 --run --raid-devices=2 /dev/sda12 /dev/sdb12 to create the device, and to dynamically create the device file if needed. What I want is the device file to be created as /dev/md12, but with the -a flag it creates it as /dev/md<first unwsed minor number>.
I have tried various options to the -a or --auto, but cannot seem to find the correct syntax. From the man page it says: -a, --auto{=no,yes,md,mdp,part,p}{NN} Instruct mdadm to create the device file if needed, and to allocate an unused minor number. "yes" or "md" causes a non-partitionable array to be used. "mdp", "part" or "p" causes a partitionable array (2.6 and later) to be used. The argumentment can also come immediately after "-a". e.g. "-ap".
Am I doing something wrong, or is there no way to get mdadm to automatically create a specific device file.
I've done it like this :
mdadm --create /dev/md12 --auto=yes --level=1 --run --raid-devices=2 /dev/...
Regards, Tim
On 11/2/07, Tim Verhoeven tim.verhoeven.be@gmail.com wrote:
On Nov 2, 2007 8:14 PM, Art Baldini rootajb@gmail.com wrote:
Hi All, I am trying to create an MD device. I am using the command: /sbin/mdadm --create --a /dev/md12 --level=1 --run --raid-devices=2 /dev/sda12 /dev/sdb12 to create the device, and to dynamically create the device file if needed. What I want is the device file to be created as /dev/md12, but with the -a flag it creates it as /dev/md<first unwsed minor number>.
I have tried various options to the -a or --auto, but cannot seem to find the correct syntax. From the man page it says: -a, --auto{=no,yes,md,mdp,part,p}{NN} Instruct mdadm to create the device file if needed, and to allocate an unused minor number. "yes" or "md" causes a non-partitionable array to be used. "mdp", "part" or "p" causes a partitionable array (2.6 and later) to be used. The argumentment can also come immediately after "-a". e.g. "-ap".
Am I doing something wrong, or is there no way to get mdadm to automatically create a specific device file.
I've done it like this :
mdadm --create /dev/md12 --auto=yes --level=1 --run --raid-devices=2 /dev/...
The only difference is that he is doing -a rather than --auto=yes. I get the same result as Art is getting when I do it your way. You can still access it as /dev/md12, but it shows up in /proc/mdstat as /dev/md0 (which is, well, weird).
Cheers...james
After some testing the placement of the -a was important. when I put it after /dev/md12, similar to what Tim posted worked.
Thanks...Art
On 11/2/07, James Olin Oden james.oden@gmail.com wrote:
On 11/2/07, Tim Verhoeven tim.verhoeven.be@gmail.com wrote:
On Nov 2, 2007 8:14 PM, Art Baldini rootajb@gmail.com wrote:
Hi All, I am trying to create an MD device. I am using the command: /sbin/mdadm --create --a /dev/md12 --level=1 --run --raid-devices=2 /dev/sda12 /dev/sdb12 to create the device, and to dynamically create the device file if
needed.
What I want is the device file to be created as /dev/md12, but with
the -a
flag it creates it as /dev/md<first unwsed minor number>.
I have tried various options to the -a or --auto, but cannot seem to
find
the correct syntax. From the man page it says: -a, --auto{=no,yes,md,mdp,part,p}{NN} Instruct mdadm to create the device file if needed, and
to
allocate an unused minor number. "yes" or "md" causes a
non-partitionable array
to be used. "mdp", "part" or "p" causes a partitionable array (2.6and later) to be used. The argumentment can also come immediately after "-a".
e.g.
"-ap".
Am I doing something wrong, or is there no way to get mdadm to
automatically
create a specific device file.
I've done it like this :
mdadm --create /dev/md12 --auto=yes --level=1 --run --raid-devices=2
/dev/...
The only difference is that he is doing -a rather than --auto=yes. I get the same result as Art is getting when I do it your way. You can still access it as /dev/md12, but it shows up in /proc/mdstat as /dev/md0 (which is, well, weird).
Cheers...james _______________________________________________ CentOS mailing list CentOS@centos.org http://lists.centos.org/mailman/listinfo/centos
On 11/4/07, Art Baldini rootajb@gmail.com wrote:
After some testing the placement of the -a was important. when I put it after /dev/md12, similar to what Tim posted worked.
Thanks...Art
Despite what I wrote previously, yeah the order seems to be important. Its seems like as soon as they proccess the --auto|-a they immediately pick the name of the md device, instead of waiting till all of the CLI is proccessed to do this. So if you have the md device defined after the --auto, it will pick the first available, and if you have it defined before --auto, then it uses what you specified. Haven't looked at the code, but this seems the only way to explain why it matters which order.
Cheers...james
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Art Baldini -
James Olin Oden -
Tim Verhoeven