From: NeilBrown <neilb@suse.de>
To: Martin Wilck <mwilck@arcor.de>
Cc: linux-raid@vger.kernel.org
Subject: Re: [PATCH 2/2] DDF: new algorithm for subarray UUID
Date: Mon, 9 Sep 2013 11:20:41 +1000 [thread overview]
Message-ID: <20130909112041.4b8401f3@notabene.brown> (raw)
In-Reply-To: <522B7D2A.4000409@arcor.de>
[-- Attachment #1: Type: text/plain, Size: 1150 bytes --]
On Sat, 07 Sep 2013 21:23:22 +0200 Martin Wilck <mwilck@arcor.de> wrote:
> On 09/06/2013 11:26 PM, mwilck@arcor.de wrote:
> > Some fake RAID BIOSes (in particular, LSI ones) change the
> > VD GUID at every boot. These GUIDs are not suitable for
> > identifying an array. Luckily the header GUID appears to
> > remain constant.
> >
> > We construct a pseudo-UUID from the header GUID and those
> > properties of the subarray that we expect to remain constant.
>
> Thinking about it once more, it may actually be better to construct the
> subarray UUID only from the container GUID and the member number (and
> name), because if we implement Grow or Reshape for DDF, the other
> properties might change.
>
> I'm open for comments and suggestions.
>
> Martin
I'd probably just base it on the container GUID and the member number.
Exclude even the name.
It is unfortunate that this change will cause all existing DDF uuids to
change even for controllers where they are currently stable.
Is it possible to detect whether a VD GUID is likely to change, and to only
use the new algorithm for those?
Thanks,
NeilBrown
[-- Attachment #2: signature.asc --]
[-- Type: application/pgp-signature, Size: 828 bytes --]
next prev parent reply other threads:[~2013-09-09 1:20 UTC|newest]
Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-09-06 21:26 [PATCH 1/2] DDF: brief_examine_subarrays_ddf: print array name mwilck
2013-09-06 21:26 ` [PATCH 2/2] DDF: new algorithm for subarray UUID mwilck
2013-09-07 19:23 ` Martin Wilck
2013-09-09 1:20 ` NeilBrown [this message]
2013-09-09 18:37 ` Martin Wilck
2013-09-09 23:51 ` NeilBrown
2013-09-09 1:15 ` [PATCH 1/2] DDF: brief_examine_subarrays_ddf: print array name NeilBrown
2013-09-09 18:31 ` Martin Wilck
2013-09-09 18:40 ` [PATCH 2/2] DDF: handle fake RAIDs with changing subarray UUIDs mwilck
2013-09-09 23:48 ` NeilBrown
2013-09-10 0:01 ` [PATCH 1/2] DDF: brief_examine_subarrays_ddf: print array name NeilBrown
2013-09-11 19:50 ` Martin Wilck
2013-09-11 19:55 ` Martin Wilck
2013-09-12 5:47 ` NeilBrown
2013-09-11 19:55 ` [PATCH 1/2] DDF: factor out array name generation mwilck
2013-09-11 19:55 ` [PATCH 2/2] DDF: brief_examine_subarrays_ddf: print array name mwilck
2013-09-12 5:44 ` NeilBrown
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=20130909112041.4b8401f3@notabene.brown \
--to=neilb@suse.de \
--cc=linux-raid@vger.kernel.org \
--cc=mwilck@arcor.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).