On 2021-11-13 at 07:26, Gene Heskett wrote:
> On Saturday 13 November 2021 06:02:35 Dan Ritter wrote:
>
>> Gene Heskett wrote:
>> You should stop there and run wipefs. I note from later mail in
>> this thread that you didn't; and then you had to reboot.
>>
>> With the array not started, or stopped, run wipefs on each of
>> the partitions.
>
> My mdadm manpage does not show the -S command. Scanniing it again to make
> sure, probably for about the 10th time and I finally found it but many
> megabytes of relatively unimportant drivel down from the top,
You keep citing this ("many megabytes"), but it doesn't sound right to
me.
$ lh /usr/share/man/man8/mdadm.8.gz
-rw-r--r-- 1 root root 33K Sep 26 00:57 /usr/share/man/man8/mdadm.8.gz
On my computer, the mdadm man page (which you say includes things that
aren't in yours, so must be bigger) is only 33K when compressed, and
more like 100K when uncompressed ('zcat /path/to/mdadm.8.gz | wc -c').
What version of mdadm do you have installed? In particular, what does
$ apt-cache policy mdadm
say?
Have you tried a Web search for 'man mdadm'? On my computer (using
Google), the very first hit from that is
https://linux.die.net/man/8/mdadm and looks substantially the same as
what I have on disk; there are also other hits which look to also
present the contents of the man page.
If your local copy is really so lacking, you might find it useful to
search these Web-based versions instead, rather than asking on the
mailing list and having us search our local copies and share excerpts.
> IMO the manpage is missleading as such an important option ought to
> be shown on the first screenfull.
There are *lots* of important options, depending on exactly what you're
doing. They can't all be presented up-front. The man page presents them
organized by type, and has a useful EXAMPLES section; by convention,
that section is near the end.
I'll agree that it isn't always easy to find the right options and the
right syntax to construct a usable command for what one wants to do,
with this structure and layout - but the EXAMPLES section is often
helpful in circumventing that, and I haven't managed to come up with an
alternative structure that would actually be better (and still be
coherent).
With any lengthy man page, there are really only two useful ways to use
it, in my experience: A: read the whole damn thing through
cover-to-cover until you find what you're after, or B: try various
search terms, exhaustively, until you find something relevant. The
latter is what I usually do with mdadm, when necessary.
> So wipefs failed.
>
> dd doesn't care so zeroed the first 1000 blocks of each drive, nuke
> mdadm.conf then rebooted, gparted was then able to reconfigure the
> drives. But then mdadm wouldn't accept because gparted had formatted
> them,
I don't usually use gparted, but by the name I'd expect it to be just a
GUI wrapper around parted, and in my experince with parted it doesn't
format a newly-created partition unless you tell it to.
> not to mention miss-labeled them, so yet another reboot, and keep
> rebooting unil somebody, Wanderer I believe, told me about "mdadm -S
> /dev/ice" command.
Actually, I didn't mention '-S' (except in passing, as part of an
excerpt from the man page), or at least didn't intend to; I mentioned
'--stop', which is synonymous, but is also easier to meaningfully search
for. (And is how I found the excerpt, by searching the man page for
'--stop'.)
I also didn't mention the "specifying a device" syntax, although I think
the man page does imply that. I cited an example which uses '--stop --scan'.
>> Then these -C commands should work well without warnings, and
>> creating a filesystem on the /dev/mdX devices will proceed without
>> warnings or errors.
>
> Yes, finally, but the mdadm man page and its poor formatting were far
> more hindrance than help. Experienced people here are to be thanked,
> and I do, but not that disastrous man page.
Please stop slamming the mdadm man page. It's certainly not perfect, but
it's not nearly as bad as you're making it out to be.
--
The Wanderer
The reasonable man adapts himself to the world; the unreasonable one
persists in trying to adapt the world to himself. Therefore all
progress depends on the unreasonable man. -- George Bernard Shaw
Attachment:
signature.asc
Description: OpenPGP digital signature