From: Michael Evans <mjevans1983@gmail.com>
To: Asdo <asdo@shiftmail.org>
Cc: Neil Brown <neilb@suse.de>, linux-raid@vger.kernel.org
Subject: Re: ANNOUNCE: mdadm 3.1.2 - A tool for managing Soft RAID under Linux
Date: Thu, 11 Mar 2010 03:58:24 -0800 [thread overview]
Message-ID: <4877c76c1003110358x2255d4bt1115ca184242ba5e@mail.gmail.com> (raw)
In-Reply-To: <4B98D322.7010101@shiftmail.org>
On Thu, Mar 11, 2010 at 3:25 AM, Asdo <asdo@shiftmail.org> wrote:
> Neil Brown wrote:
>>
>> I am pleased to announce the availability of
>> mdadm version 3.1.2
>>
>> [CUT]
>>
>> Significant changes are:
>> - The default metadata has change again (sorry about that).
>> It is now v1.2 and will hopefully stay that way. [CUT]
>>
>
> I remember some discussion about alignment for 1.1 and 1.2: is it possible
> on 1.2 to guarantee alignment of RAID device on the physical devices?
> 4K alignment would be needed on SSDs and 2TB disks w/ 4k physical 512b
> logical emulation. Actually on SSDs the alignment could be even more than
> 4k, I am not sure.
> Should we bypass the defaults and put 1.0 metadata on those?
> What was the downside of 1.0 so that it was not made default?
>
> Thanks for your great job
> --
> To unsubscribe from this list: send the line "unsubscribe linux-raid" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at http://vger.kernel.org/majordomo-info.html
>
1.0 puts the metadata at the end. You run in to situations where
various tools that detect what's inside of a block device get confused
about if it's an md member, or whatever's been stuffed inside of md
(and is thus stored at the front) instead.
What would be nice would be the ability to specify a non-default
alignment unit and a reference sector in the backing device to use for
the start of alignment. However I don't think anyone who's really
needed it has yet seen fit to provide a patch.
Presuming someone did want to write a patch, is the above outlined
pair of options desirable as the solution, and what sort of long/short
names might be used?
--
To unsubscribe from this list: send the line "unsubscribe linux-raid" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
next prev parent reply other threads:[~2010-03-11 11:58 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-03-10 5:11 ANNOUNCE: mdadm 3.1.2 - A tool for managing Soft RAID under Linux Neil Brown
2010-03-11 11:25 ` Asdo
2010-03-11 11:58 ` Michael Evans [this message]
2010-03-11 12:29 ` Luca Berra
2010-03-11 13:24 ` Asdo
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=4877c76c1003110358x2255d4bt1115ca184242ba5e@mail.gmail.com \
--to=mjevans1983@gmail.com \
--cc=asdo@shiftmail.org \
--cc=linux-raid@vger.kernel.org \
--cc=neilb@suse.de \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).