From mboxrd@z Thu Jan 1 00:00:00 1970 From: Doug Ledford Subject: Re: [ANNOUNCE] mdadm-3.1 has been withdrawn Date: Mon, 09 Nov 2009 16:00:07 -0500 Message-ID: <4AF882D7.4030503@redhat.com> References: <19187.50708.551325.297625@notabene.brown> <4AF829B2.5090001@redhat.com> <423765b7af1be77f0a40dcbbb1f65c4b.squirrel@neil.brown.name> Mime-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="------------enigDCD84C2218F8732F410CB924" Return-path: In-Reply-To: <423765b7af1be77f0a40dcbbb1f65c4b.squirrel@neil.brown.name> Sender: linux-raid-owner@vger.kernel.org To: Neil F Brown Cc: linux-raid@vger.kernel.org List-Id: linux-raid.ids This is an OpenPGP/MIME signed message (RFC 2440 and 3156) --------------enigDCD84C2218F8732F410CB924 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable On 11/09/2009 03:22 PM, Neil F Brown wrote: > On Tue, November 10, 2009 1:39 am, Doug Ledford wrote: >> On 11/06/2009 01:45 AM, Neil Brown wrote: >>> >>> Greetings. >>> >>> About a week ago I released mdadm-3.1 >>> I have now 'withdrawn' it meaning that it doesn't appear on the >>> kernel.org mirrors any more, and I ask people not to use it. >> >> Although the cause for this sucks, I was actually going to suggest tha= t >> since 3.1 is a version bump, that we take the opportunity to change a >> few defaults. Like switching to version 1 superblocks instead of >> version 0 by default. And changing the default chunk size to 512k >> instead of 64k. The time has simply come for the 0->1 superblock >> change, and I have a good deal of data showing that for SATA disks at >> least, the 512k chunk size is the typical sweet spot. >=20 > I had been toying with that idea myself - certainly of changing the > defaults soon. > I'm tempted to make the default metadata "1.1" though possibly not for > RAID1. For RAID0,4,5,6,10 there is no value in having the metadata > at the end of the device. For RAID1 there is as it makes booting off > any member easier. > Thoughts? While it makes booting off of a raid1 easier, raid1 is *precisely* the level that is prone to silent data corrupt due to the individual members being able to be mounted while not part of a running raid array. I would make it default to 1.1 period, and force distros or other people to either A) update the boot loader to something that can handle a 1.1 superblock (grub2 should be able to) or B) manually set it to 1.0 instead= =2E >=20 > I'm certainly happy with increasing the chunksize to 512K. >=20 > NeilBrown --=20 Doug Ledford GPG KeyID: CFBFF194 http://people.redhat.com/dledford Infiniband specific RPMs available at http://people.redhat.com/dledford/Infiniband --------------enigDCD84C2218F8732F410CB924 Content-Type: application/pgp-signature; name="signature.asc" Content-Description: OpenPGP digital signature Content-Disposition: attachment; filename="signature.asc" -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.9 (GNU/Linux) iEYEARECAAYFAkr4gtcACgkQg6WylM+/8ZRKSgCfXTFe6OuFWVvo1MxTWvnZHFli FhoAn0w4cd89k12hmgimgj+yEKdcCseM =DPUR -----END PGP SIGNATURE----- --------------enigDCD84C2218F8732F410CB924--