Neil Brown wrote:
> On Friday December 2, eyal@xxxxxxxxxxxxxx wrote:
>
>>Neil Brown wrote:
>>
>>>>Q1) What is the correct command to bring these three up as
>>>> degraded?
>>>
>>>
>>> mdadm --assemble --force /dev/mdX /dev/sd[abc]1
>>>
>>>However this won't work with the superblocks you have. So
>>>
>>> mdadm --create /dev/mdX -l5 -c256 -n4 missing /dev/sda /dev/sdb /dev/sdc
>>
>>I do not see 'missing' the the mdadm manpage, but maybe Debian is too
>>far behind?
>
>
> It is in the section on "CREATE MODE"
>
> To create a "degraded" array in which some devices are missing, simply
> give the word "missing" in place of a device name. This will cause
> mdadm to leave the corresponding slot in the array empty. For a RAID4
> or RAID5 array at most one slot can be "missing"; for a RAID6 array at
> most two slots. For a RAID1 array, only one real device needs to be
> given. All of the others can be "missing".
>
>
>
>># mdadm --version
>>mdadm - v1.9.0 - 04 February 2005
>
>
> The section I quoted is from the man page for 1.12.0, but that text
> certainly predates 1.9.0.
Here is the Debian (stable) relevant 'man mdadm' section:
CREATE MODE
Usage: mdadm --create device --chunk=X --level=Y
--raid-disks=Z devices
This usage will initialise a new md array, associate some devices with
it, and activate the array.
As devices are added, they are checked to see if they contain raid
superblocks or filesystems. They are also check to see if the variance
in device size exceeds 1%.
If any discrepancy is found, the array will not automatically be run,
though the presence of a --run can override this caution.
The General Management options that are valid with --create are:
--run insist of running the array even if some devices look like they
might be in use.
--readonly
start the array readonly - not supported yet.
Maybe they have their own "special" man page?
>>I built it anyway and I do not see 'missing' listed in
>> mdadm --create --help
>
> I do.
>
> $ /sbin/mdadm --create --help
> Usage: mdadm --create device -chunk=X --level=Y --raid-devices=Z devices
>
> This usage will initialise a new md array, associate some
> devices with it, and activate the array. In order to create an
> array with some devices missing, use the special word 'missing' in
> ^^^^^^^
> place of the relevant device name.
True, I missed it :-(
fsck finished clean too, thanks again.
--
Eyal Lebedinsky (eyal@xxxxxxxxxxxxxx) <http://samba.org/eyal/>
attach .zip as .dat
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