From mboxrd@z Thu Jan 1 00:00:00 1970 Subject: Re: [RFC][PATCH 0/9] Network receive deadlock prevention for NBD From: Peter Zijlstra In-Reply-To: <20060814051323.GA1335@2ka.mipt.ru> References: <1155127040.12225.25.camel@twins> <20060809130752.GA17953@2ka.mipt.ru> <1155130353.12225.53.camel@twins> <20060809.165431.118952392.davem@davemloft.net> <1155189988.12225.100.camel@twins> <44DF888F.1010601@google.com> <20060814051323.GA1335@2ka.mipt.ru> Content-Type: text/plain Date: Mon, 14 Aug 2006 08:45:43 +0200 Message-Id: <1155537943.5696.118.camel@twins> Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org Return-Path: To: Evgeniy Polyakov Cc: Daniel Phillips , David Miller , linux-mm@kvack.org, linux-kernel@vger.kernel.org, netdev@vger.kernel.org List-ID: On Mon, 2006-08-14 at 09:13 +0400, Evgeniy Polyakov wrote: > On Sun, Aug 13, 2006 at 01:16:15PM -0700, Daniel Phillips (phillips@google.com) wrote: > > Indeed. The rest of the corner cases like netfilter, layered protocol and > > so on need to be handled, however they do not need to be handled right now > > in order to make remote storage on a lan work properly. The sane thing for > > the immediate future is to flag each socket as safe for remote block IO or > > not, then gradually widen the scope of what is safe. We need to set up an > > opt in strategy for network block IO that views such network subsystems as > > ipfilter as not safe by default, until somebody puts in the work to make > > them safe. > > Just for clarification - it will be completely impossible to login using > openssh or some other priveledge separation protocol to the machine due > to the nature of unix sockets. So you will be unable to manage your > storage system just because it is in OOM - it is not what is expected > from reliable system. > > > But really, if you expect to run reliable block IO to Zanzibar over an ssh > > tunnel through a firewall, then you might also consider taking up bungie > > jumping with the cord tied to your neck. > > Just pure openssh for control connection (admin should be able to > login). These periods of degenerated functionality should be short and infrequent albeit critical for machine recovery. Would you rather have a slower ssh login (the machine will recover) or drive/fly to Zanzibar to physically reboot the machine? -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org