Groups > linux.debian.user > #242066

Re: Where do I find the definitive man page for mdadm?

From	Gene Heskett <gheskett@shentel.net>
Newsgroups	linux.debian.user
Subject	Re: Where do I find the definitive man page for mdadm?
Date	2021-11-12 15:50 +0100
Message-ID	<DiG2l-6yd-1@gated-at.bofh.it> (permalink)
References	<DiEtz-5Mf-3@gated-at.bofh.it> <DiFpD-6l3-5@gated-at.bofh.it>
Organization	none,nada,zip

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On Friday 12 November 2021 08:49:21 Dan Ritter wrote:

> Gene Heskett wrote:
> > The man page we have goes on and on for megabytes without ever
> > giving an example.
> >
> > I thought maybe it could scan for devices so that I could build an
> > mdadm.conf but it wont do a --scan by itself.
>
> You are looking for
>
> mdadm --detail  --scan
>
Null return on stretch version of mdadm. Supposedly up to date as of an 
hour ago.

> It is in that man page, as an example under --detail.

Not in the stretch man page.  And its sounding as if I should do that 
during the bullseye install to get the more capable mdadm, but will the 
devices have the same names? With the reputation for volatility of 
device names a mistake there could destroy 23 years of data.

> > But I don't see an option (or recognize it if it is there) to give
> > it a controller id and let it make a raid10 out of the 4 identical
> > drives it could find there.
> >
> > If there is such a critter, point me at it please.
>
> You have to feed mdadm the drives you want specifically; there's
> no scattershot approach.
>
> Let's say that the drives are /dev/sdf, /dev/sdg, /dev/sdh and
> /dev/sdi.
>
> (You can re-confirm what drive is what via hdparm -i, or
> smartctl.)
>
> If you have data on them, it will be wiped out. You should copy
> off anything important, and then run wipefs on each of them.
>
> Then, creation is
>
> # mdadm -C /dev/md0 --level=10 --raid-devices=4 /dev/sdf /dev/sdg
> /dev/sdh /dev/sdi
>
> (assuming you want it named /dev/md0 and there isn't one
> already)
>
> Then you can make a filesystem on /dev/md0 and put it in your
> fstab, mount it, and copy data over to it.

So mkfs.ext4 /md0 is required, ok

> > What I'd like to do when I install bullseye, is use this raid10 for
> > the /home partition in the bullseye install.
>
> The installer will recognize it as an md RAID and can be told that you
> want to use it as-is, or you can destroy it and re-create it without
> data.
>
> -dsr-
Thanks Dan.

Cheers, Gene Heskett.
-- 
"There are four boxes to be used in defense of liberty:
 soap, ballot, jury, and ammo. Please use in that order."
-Ed Howdershelt (Author, 1940)
If we desire respect for the law, we must first make the law respectable.
 - Louis D. Brandeis
Genes Web page <http://geneslinuxbox.net:6309/gene>

Thread

Where do I find the definitive man page for mdadm? Gene Heskett <gheskett@shentel.net> - 2021-11-12 14:10 +0100
  Re: Where do I find the definitive man page for mdadm? Dan Ritter <dsr@randomstring.org> - 2021-11-12 15:10 +0100
    Re: Where do I find the definitive man page for mdadm? Gene Heskett <gheskett@shentel.net> - 2021-11-12 15:30 +0100
    Re: Where do I find the definitive man page for mdadm? Gene Heskett <gheskett@shentel.net> - 2021-11-12 15:50 +0100
      Re: Where do I find the definitive man page for mdadm? Dan Ritter <dsr@randomstring.org> - 2021-11-12 16:40 +0100
        Re: Where do I find the definitive man page for mdadm? Gene Heskett <gheskett@shentel.net> - 2021-11-12 17:50 +0100
          Re: Where do I find the definitive man page for mdadm? The Wanderer <wanderer@fastmail.fm> - 2021-11-12 17:50 +0100
            Re: Where do I find the definitive man page for mdadm? Gene Heskett <gheskett@shentel.net> - 2021-11-12 18:20 +0100
          Re: Where do I find the definitive man page for mdadm? Andy Smith <andy@strugglers.net> - 2021-11-13 13:40 +0100
            Re: Where do I find the definitive man page for mdadm? Gene Heskett <gheskett@shentel.net> - 2021-11-13 14:10 +0100
            Re: Where do I find the definitive man page for mdadm? Gene Heskett <gheskett@shentel.net> - 2021-11-13 14:40 +0100
              Re: Where do I find the definitive man page for mdadm? Andy Smith <andy@strugglers.net> - 2021-11-13 15:00 +0100
                Re: Where do I find the definitive man page for mdadm? Gene Heskett <gheskett@shentel.net> - 2021-11-13 15:30 +0100
                Re: Where do I find the definitive man page for mdadm? Andy Smith <andy@strugglers.net> - 2021-11-13 16:00 +0100
                Re: Where do I find the definitive man page for mdadm? David Wright <deblis@lionunicorn.co.uk> - 2021-11-13 17:40 +0100
                Re: Where do I find the definitive man page for mdadm? Gene Heskett <gheskett@shentel.net> - 2021-11-13 19:20 +0100
                Re: Where do I find the definitive man page for mdadm? Andy Smith <andy@strugglers.net> - 2021-11-13 21:50 +0100
                Re: Where do I find the definitive man page for mdadm? Gene Heskett <gheskett@shentel.net> - 2021-11-13 23:00 +0100
                Re: Where do I find the definitive man page for mdadm? Charles Curley <charlescurley@charlescurley.com> - 2021-11-14 00:10 +0100
                Re: Where do I find the definitive man page for mdadm? Greg Wooledge <greg@wooledge.org> - 2021-11-14 00:40 +0100
                Re: Where do I find the definitive man page for mdadm? Gene Heskett <gheskett@shentel.net> - 2021-11-14 01:30 +0100
                Re: Where do I find the definitive man page for mdadm? Andy Smith <andy@strugglers.net> - 2021-11-14 09:10 +0100
                Re: Where do I find the definitive man page for mdadm? David Wright <deblis@lionunicorn.co.uk> - 2021-11-14 18:00 +0100
                Re: Where do I find the definitive man page for mdadm? "Thomas Schmitt" <scdbackup@gmx.net> - 2021-11-14 19:40 +0100
                Re: Where do I find the definitive man page for mdadm? David Wright <deblis@lionunicorn.co.uk> - 2021-11-15 02:40 +0100
                Re: Where do I find the definitive man page for mdadm? "Thomas Schmitt" <scdbackup@gmx.net> - 2021-11-15 09:10 +0100
                Re: Where do I find the definitive man page for mdadm? David Wright <deblis@lionunicorn.co.uk> - 2021-11-16 05:30 +0100
                Re: Where do I find the definitive man page for mdadm? Tom Dial <tddial@comcast.net> - 2021-11-14 05:00 +0100
                Re: Where do I find the definitive man page for mdadm? Greg Wooledge <greg@wooledge.org> - 2021-11-14 05:10 +0100
                Re: Where do I find the definitive man page for mdadm? Gene Heskett <gheskett@shentel.net> - 2021-11-14 05:40 +0100
      Re: Where do I find the definitive man page for mdadm? Charles Curley <charlescurley@charlescurley.com> - 2021-11-12 18:10 +0100
        Re: Where do I find the definitive man page for mdadm? Charles Curley <charlescurley@charlescurley.com> - 2021-11-12 19:00 +0100
      Re: Where do I find the definitive man page for mdadm? "Andrew M.A. Cater" <amacater@einval.com> - 2021-11-12 18:10 +0100
        Re: Where do I find the definitive man page for mdadm? Gene Heskett <gheskett@shentel.net> - 2021-11-12 20:10 +0100
          Re: Where do I find the definitive man page for mdadm? Dan Ritter <dsr@randomstring.org> - 2021-11-12 21:40 +0100
            Re: Where do I find the definitive man page for mdadm? Gene Heskett <gheskett@shentel.net> - 2021-11-12 23:00 +0100
              Re: Where do I find the definitive man page for mdadm? The Wanderer <wanderer@fastmail.fm> - 2021-11-12 23:10 +0100
                Re: Where do I find the definitive man page for mdadm? Gene Heskett <gheskett@shentel.net> - 2021-11-13 01:00 +0100
    Re: Where do I find the definitive man page for mdadm? Gene Heskett <gheskett@shentel.net> - 2021-11-12 22:30 +0100
      Re: Where do I find the definitive man page for mdadm? Dan Ritter <dsr@randomstring.org> - 2021-11-13 12:30 +0100
        Re: Where do I find the definitive man page for mdadm? Gene Heskett <gheskett@shentel.net> - 2021-11-13 13:30 +0100
          Re: Where do I find the definitive man page for mdadm? The Wanderer <wanderer@fastmail.fm> - 2021-11-13 13:50 +0100
            Re: Where do I find the definitive man page for mdadm? Gene Heskett <gheskett@shentel.net> - 2021-11-13 15:00 +0100
          Re: Where do I find the definitive man page for mdadm? David Wright <deblis@lionunicorn.co.uk> - 2021-11-13 17:50 +0100
            Re: Where do I find the definitive man page for mdadm? Gene Heskett <gheskett@shentel.net> - 2021-11-13 19:40 +0100
  Re: Where do I find the definitive man page for mdadm? Charles Curley <charlescurley@charlescurley.com> - 2021-11-12 15:10 +0100
    Re: Where do I find the definitive man page for mdadm? Gene Heskett <gheskett@shentel.net> - 2021-11-12 15:30 +0100
      Re: Where do I find the definitive man page for mdadm? Andy Smith <andy@strugglers.net> - 2021-11-12 16:40 +0100
        Re: Where do I find the definitive man page for mdadm? Gene Heskett <gheskett@shentel.net> - 2021-11-12 18:10 +0100
          Re: Where do I find the definitive man page for mdadm? Charles Curley <charlescurley@charlescurley.com> - 2021-11-12 19:20 +0100
            Re: Where do I find the definitive man page for mdadm? Gene Heskett <gheskett@shentel.net> - 2021-11-12 20:20 +0100
              Re: Where do I find the definitive man page for mdadm? Charles Curley <charlescurley@charlescurley.com> - 2021-11-13 00:10 +0100
                Re: Where do I find the definitive man page for mdadm? Andy Smith <andy@strugglers.net> - 2021-11-13 12:40 +0100
        Re: Where do I find the definitive man page for mdadm? Dan Ritter <dsr@randomstring.org> - 2021-11-12 18:20 +0100
          Re: Where do I find the definitive man page for mdadm? Gene Heskett <gheskett@shentel.net> - 2021-11-12 19:50 +0100
            Re: Where do I find the definitive man page for mdadm? Charles Curley <charlescurley@charlescurley.com> - 2021-11-12 23:50 +0100
              Re: Where do I find the definitive man page for mdadm? Gene Heskett <gheskett@shentel.net> - 2021-11-13 01:10 +0100
          Re: Where do I find the definitive man page for mdadm? Andy Smith <andy@strugglers.net> - 2021-11-13 12:50 +0100
      Re: Where do I find the definitive man page for mdadm? Charles Curley <charlescurley@charlescurley.com> - 2021-11-12 17:50 +0100
        Re: Where do I find the definitive man page for mdadm? Gene Heskett <gheskett@shentel.net> - 2021-11-12 18:10 +0100
          Re: Where do I find the definitive man page for mdadm? Charles Curley <charlescurley@charlescurley.com> - 2021-11-12 19:00 +0100
            Re: Where do I find the definitive man page for mdadm? Gene Heskett <gheskett@shentel.net> - 2021-11-12 20:30 +0100
              Re: Where do I find the definitive man page for mdadm? Charles Curley <charlescurley@charlescurley.com> - 2021-11-13 00:20 +0100
  Re: Where do I find the definitive man page for mdadm? David Wright <deblis@lionunicorn.co.uk> - 2021-11-12 15:30 +0100
    Re: Where do I find the definitive man page for mdadm? Gene Heskett <gheskett@shentel.net> - 2021-11-12 16:10 +0100

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