From mboxrd@z Thu Jan 1 00:00:00 1970 From: Roman Mamedov Subject: Re: RAID HDDs spin up sequence Date: Tue, 1 Feb 2011 17:39:32 +0500 Message-ID: <20110201173932.2455a20f@natsu> References: <20110131201823.GA15704@lazy.lzy> <20110131222348.GA15912@lazy.lzy> <20110131230703.GA16834@lazy.lzy> <4D4765B2.7090002@cfl.rr.com> Mime-Version: 1.0 Content-Type: multipart/signed; micalg=PGP-SHA1; boundary="Sig_/RJJO6N3F8tTbFI7Mbn6=wSp"; protocol="application/pgp-signature" Return-path: In-Reply-To: <4D4765B2.7090002@cfl.rr.com> Sender: linux-raid-owner@vger.kernel.org To: Phillip Susi Cc: Piergiorgio Sartor , Roberto Spadim , linux-raid@vger.kernel.org List-Id: linux-raid.ids --Sig_/RJJO6N3F8tTbFI7Mbn6=wSp Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: quoted-printable On Mon, 31 Jan 2011 20:45:22 -0500 Phillip Susi wrote: > If you want to force serial wakeup, you would need to do some hacking in= =20 > libata or the scsi layer to only allow one wakeup request at once. Of=20 > course, with a 6 disk raid where each disk takes 6 seconds to spin up,=20 > you will be waiting 36 seconds to get your data. Not exactly desirable. Well, if the other option is to have your system hard-reset because the PSU overloads from 12-20-24 disks spinning up at once (you know staggered spin-= up is supported by disks/controllers for a reason), then the wait does not loo= k so bad. My take on the problem: just don't spin down your RAIDs. --=20 With respect, Roman --Sig_/RJJO6N3F8tTbFI7Mbn6=wSp Content-Type: application/pgp-signature; name=signature.asc Content-Disposition: attachment; filename=signature.asc -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.10 (GNU/Linux) iEYEARECAAYFAk1H/wQACgkQTLKSvz+PZwihnwCfUZLy2kWJe6dPp3xPYuxZY1g/ BRIAoIe/xrjKMSThUehGSc6nvzFQbifK =1vwx -----END PGP SIGNATURE----- --Sig_/RJJO6N3F8tTbFI7Mbn6=wSp--