From mboxrd@z Thu Jan 1 00:00:00 1970 From: Roman Mamedov Subject: Re: upgrading LSI SAS9211-8i fw IR->IT Date: Tue, 24 Oct 2017 22:59:26 +0500 Message-ID: <20171024225926.48873932@natsu> References: <08feefcc-14d0-e7ec-aa23-927ecbb63ac3@eyal.emu.id.au> <20171024171457.563fbb2a@natsu> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: Sender: linux-raid-owner@vger.kernel.org To: Eyal Lebedinsky Cc: list linux-raid List-Id: linux-raid.ids On Wed, 25 Oct 2017 00:04:37 +1100 Eyal Lebedinsky wrote: > I want to avoid the risk of the IR fw writing any metadata to the disks which already > hold a software RAID. > > Is it not the case that the IR fw may mess with the disks (I read a comment suggesting it might)? I believe when HW RAID controllers do that, they set up HPA to reserve a small area at the end, and write the metadata there. But just checked, there is no HPA on any of the 3 disks that I have connected. $ sudo hdparm -N /dev/sdi /dev/sdi: max sectors = 3907029168/3907029168, HPA is disabled $ sudo hdparm -N /dev/sdh /dev/sdh: max sectors = 3907029168/3907029168, HPA is disabled $ sudo hdparm -N /dev/sdg /dev/sdg: max sectors = 3907029168/3907029168, HPA is disabled You can test by connecting some disk with data you don't care about, and checking if its contents get modified (especially at the end), or if it gets HPA enabled. -- With respect, Roman