[CentOS] Re: mdadm --stop

Scott Silva ssilva at sgvwater.com
Tue Nov 6 21:01:52 UTC 2007


on 11/6/2007 12:40 PM Art Baldini spake the following:
> Scott, thanks, that worked.  Is this different from the previous
> behavior?  I am setting up a system with the old version of mdadm I
> was using to test this, but I am fairly sure this used to work for me.
> 
> ...Art
> 
AFAIR this is the norm. Look at the manpage on the old system if you want to 
verify. That line I quoted is not very far from the top.

<quote>

Name
mdadm - manage MD devices aka Linux Software Raid.
Synopsis

mdadm[mode] <raiddevice> [options] <component-devices>
Description
RAID devices are virtual devices created from two or more real block devices. 
This allows multiple devices (typically disk drives or partitions there-of) to 
be combined into a single device to hold (for example) a single filesystem. 
Some RAID levels include redundancy and so can survive some degree of device 
failure.

Linux Software RAID devices are implemented through the md (Multiple Devices) 
device driver.

Currently, Linux supports LINEAR md devices, RAID0 (striping), RAID1 
(mirroring), RAID4, RAID5, RAID6, RAID10, MULTIPATH, and FAULTY.

MULTIPATH is not a Software RAID mechanism, but does involve multiple devices. 
For MULTIPATH each device is a path to one common physical storage device.

FAULTY is also not true RAID, and it only involves one device. It provides a 
layer over a true device that can be used to inject faults.
Modes
mdadm has 7 major modes of operation:

Assemble
     Assemble the parts of a previously created array into an active array. 
Components can be explicitly given or can be searched for. mdadm checks that 
the components do form a bona fide array, and can, on request, fiddle 
superblock information so as to assemble a faulty array.
Build
     Build an array that doesn't have per-device superblocks. For these sorts 
of arrays, mdadm cannot differentiate between initial creation and subsequent 
assembly of an array. It also cannot perform any checks that appropriate 
devices have been requested. Because of this, the Build mode should only be 
used together with a complete understanding of what you are doing.
Create
     Create a new array with per-device superblocks.
Follow or Monitor
     Monitor one or more md devices and act on any state changes. This is only 
meaningful for raid1, 4, 5, 6, 10 or multipath arrays as only these have 
interesting state. raid0 or linear never have missing, spare, or failed 
drives, so there is nothing to monitor.
Grow
     Grow (or shrink) an array, or otherwise reshape it in some way. Currently 
supported growth options including changing the active size of component 
devices in RAID level 1/4/5/6 and changing the number of active devices in RAID1.
Manage
     This is for doing things to specific components of an array such as 
adding new spares and removing faulty devices.
Misc
     This is an 'everything else' mode that supports operations on active 
arrays, operations on component devices such as erasing old superblocks, and 
information gathering operations.

Options
Options for selecting a mode are:

-A, --assemble
     Assemble a pre-existing array.
-B, --build
     Build a legacy array without superblocks.
-C, --create
     Create a new array.
-F, --follow, --monitor
     Select Monitor mode.
-G, --grow
     Change the size or shape of an active array.

If a device is given before any options, or if the first option is --add, 
--fail, or --remove, then the MANAGE mode is assume. Anything other than these 
will cause the Misc mode to be assumed.
Options that are not mode-specific are:

</quote>


on 11/6/2007 12:40 PM Art Baldini spake the following:
> Scott, thanks, that worked.  Is this different from the previous
> behavior?  I am setting up a system with the old version of mdadm I
> was using to test this, but I am fairly sure this used to work for me.
> 
> ...Art
> 
> On Nov 6, 2007 3:17 PM, Scott Silva <ssilva at sgvwater.com> wrote:
>> on 11/6/2007 12:01 PM Art Baldini spake the following:
>>
>>> Updating the command syntax below.
>>>
>>> On Nov 6, 2007 3:00 PM, Art Baldini <rootajb at gmail.com> wrote:
>>>> I have been trying to delete an md.  I have recently updated to
>>>> version 1.12 of mdadm.
>>>> I used to be able to do mdadm /dev/md12 --stop.  It does not seem to be
>>>> stopping, but I do not get any error and the $?/return code is 0.
>>>>
>>>> The --verbose option for mdadm does nothing for --stop.  How do I
>>>> determine why this is not successful?
>>>>
>>>>
>>>> Thanks...Art
>>>>
>> According to the man page;
>> If a device is given before any options, or if the first option is --add,
>> --fail, or --remove, then the MANAGE mode is assume. Anything other than these
>> will cause the Misc mode to be assumed.
>> So try mdadm --stop /dev/md12  with the device last.
>>
>> --
>> MailScanner is like deodorant...
>> You hope everybody uses it, and
>> you notice quickly if they don't!!!!
>>
>> _______________________________________________
>> CentOS mailing list
>> CentOS at centos.org
>> http://lists.centos.org/mailman/listinfo/centos
>>


</quote>

-- 
MailScanner is like deodorant...
You hope everybody uses it, and
you notice quickly if they don't!!!!




More information about the CentOS mailing list