[CentOS] Re: mdadm --stop

Tue Nov 6 21:44:01 UTC 2007
Art Baldini <rootajb at gmail.com>

My "new" version is Centos 4.5.  I just checked CentOS 5 and it has
version: mdadm-2.5.4-3.el5.i386.  This has the updated man page.

Thanks...Art

On Nov 6, 2007 4:08 PM, Art Baldini <rootajb at gmail.com> wrote:
> What version are you using, I do not see that in either version of man
> page for mine.
>
> # rpm -qi mdadm
> Name        : mdadm                        Relocations: (not relocatable)
> Version     : 1.12.0                            Vendor: CentOS
> Release     : 2                             Build Date: Thu 03 May
> 2007 01:30:01 PM EDT
> ...
>
>
> On Nov 6, 2007 4:01 PM, Scott Silva <ssilva at sgvwater.com> wrote:
> > 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.
> > >>
> > >> --
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> > >> You hope everybody uses it, and
> > >> you notice quickly if they don't!!!!
> > >>
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> > >>
> >
> >
> > </quote>
> >
> > --
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> >
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