From mboxrd@z Thu Jan 1 00:00:00 1970 From: Roman Mamedov Subject: Re: RAID6 and crashes (reporting back re. --bitmap) Date: Mon, 14 Jun 2010 17:53:27 +0600 Message-ID: <20100614175327.57f05bb1@natsu> References: <4C1128C2.4020105@meetinghouse.net> <001501cb091f$07ac4e40$1704eac0$@woodlea.com> <20100611145019.6f1a5e7d@notabene.brown> <201006131628.35037.bernd.schubert@fastmail.fm> <20100614090520.2ae5a961@notabene.brown> <20100614151425.11f91562@natsu> <20100614194742.4a383a3f@notabene.brown> Mime-Version: 1.0 Content-Type: multipart/signed; micalg=PGP-SHA1; boundary="Sig_/s4oJ5R+_7SakiPr2KRr/8wD"; protocol="application/pgp-signature" Return-path: In-Reply-To: <20100614194742.4a383a3f@notabene.brown> Sender: linux-raid-owner@vger.kernel.org To: Neil Brown Cc: Bernd Schubert , linux-raid@vger.kernel.org List-Id: linux-raid.ids --Sig_/s4oJ5R+_7SakiPr2KRr/8wD Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: quoted-printable On Mon, 14 Jun 2010 19:47:42 +1000 Neil Brown wrote: > When you create an array an specify that a bitmap be added at the same ti= me, > there is more flexibility for size and location of the bitmap. It can ea= sily > be more that 3K in that case. >=20 > So presumably this array was created with a bitmap, rather than created > without a bitmap and had a bitmap added later with --grow. Correct? Yes, as far as I remember. However, it seems a bit unfortunate to have any significant difference between adding the bitmap right when creating the array, and adding it later. For that reason, I'd suggest reserving more spa= ce in the metadata than 3K, even if the bitmap isn't requested - and even if it won't be added later, then that space could prove useful for something else that might require it later. Maybe 64, 128 or 256K - still miniscule compar= ed to the array size, and could provide some nice flexibility for the future. --=20 With respect, Roman --Sig_/s4oJ5R+_7SakiPr2KRr/8wD Content-Type: application/pgp-signature; name=signature.asc Content-Disposition: attachment; filename=signature.asc -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.10 (GNU/Linux) iEYEARECAAYFAkwWGDcACgkQTLKSvz+PZwjfVQCeKW+CXHM3ukhAxcI0jFM13nOC 7LAAnRxgLOcIkqmX4ro3cJUM01/64nDF =SrkB -----END PGP SIGNATURE----- --Sig_/s4oJ5R+_7SakiPr2KRr/8wD--