From owner-freebsd-questions@freebsd.org Tue May 14 15:59:06 2019 Return-Path: Delivered-To: freebsd-questions@mailman.ysv.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mailman.ysv.freebsd.org (Postfix) with ESMTP id A750D1591CB1 for ; Tue, 14 May 2019 15:59:06 +0000 (UTC) (envelope-from hartzell@alerce.com) Received: from griffon.alerce.com (griffon.alerce.com [206.125.171.162]) (using TLSv1 with cipher DHE-RSA-CAMELLIA256-SHA (256/256 bits)) (Client CN "griffon.alerce.com", Issuer "griffon.alerce.com" (not verified)) by mx1.freebsd.org (Postfix) with ESMTPS id BCAE372815; Tue, 14 May 2019 15:59:05 +0000 (UTC) (envelope-from hartzell@alerce.com) Received: from griffon.alerce.com (localhost [127.0.0.1]) by griffon.alerce.com (Postfix) with ESMTP id 491052842E; Tue, 14 May 2019 08:59:03 -0700 (PDT) Received: from postfix.alerce.com (76-226-160-236.lightspeed.sntcca.sbcglobal.net [76.226.160.236]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (Client did not present a certificate) by griffon.alerce.com (Postfix) with ESMTPSA id 283882842D; Tue, 14 May 2019 08:59:03 -0700 (PDT) Received: by postfix.alerce.com (Postfix, from userid 501) id DF72C200E03FC0; Tue, 14 May 2019 08:59:01 -0700 (PDT) From: George Hartzell MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Message-ID: <23770.58821.826610.399467@alice.local> Date: Tue, 14 May 2019 08:59:01 -0700 To: Matthew Seaman Cc: freebsd-questions@freebsd.org Subject: Re: Suggestions for working with unstable nvme dev names in AWS In-Reply-To: <08660a2a-489f-8172-22ee-47aeba315986@FreeBSD.org> References: <23770.10599.687213.86492@alice.local> <08660a2a-489f-8172-22ee-47aeba315986@FreeBSD.org> X-Mailer: VM 8.2.0b under 26.1 (x86_64-apple-darwin14.5.0) Reply-To: hartzell@alerce.com X-Virus-Scanned: ClamAV using ClamSMTP X-Rspamd-Queue-Id: BCAE372815 X-Spamd-Bar: -- Authentication-Results: mx1.freebsd.org; spf=pass (mx1.freebsd.org: domain of hartzell@alerce.com designates 206.125.171.162 as permitted sender) smtp.mailfrom=hartzell@alerce.com X-Spamd-Result: default: False [-2.78 / 15.00]; ARC_NA(0.00)[]; RCVD_VIA_SMTP_AUTH(0.00)[]; HAS_REPLYTO(0.00)[hartzell@alerce.com]; FROM_HAS_DN(0.00)[]; TO_DN_SOME(0.00)[]; R_SPF_ALLOW(-0.20)[+mx]; TO_MATCH_ENVRCPT_ALL(0.00)[]; MIME_GOOD(-0.10)[text/plain]; DMARC_NA(0.00)[alerce.com]; REPLYTO_ADDR_EQ_FROM(0.00)[]; NEURAL_HAM_LONG(-0.99)[-0.992,0]; RCVD_COUNT_THREE(0.00)[4]; IP_SCORE(-0.03)[asn: 25795(-0.09), country: US(-0.06)]; MX_GOOD(-0.01)[cached: griffon.alerce.com]; RCPT_COUNT_TWO(0.00)[2]; NEURAL_HAM_SHORT(-0.58)[-0.582,0]; NEURAL_HAM_MEDIUM(-0.86)[-0.862,0]; FROM_EQ_ENVFROM(0.00)[]; R_DKIM_NA(0.00)[]; MIME_TRACE(0.00)[0:+]; ASN(0.00)[asn:25795, ipnet:206.125.168.0/21, country:US]; RCVD_TLS_LAST(0.00)[] X-BeenThere: freebsd-questions@freebsd.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: User questions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 14 May 2019 15:59:07 -0000 Matthew Seaman writes: > On 14/05/2019 03:35, George Hartzell wrote: > > Can anyone speak to the current state of device names for nvme disks > > on AWS using the FreeBSD 12 AMI's? Is name-stability an issue? If > > so, is there a work-around? > > I don't know about device name stability in AWS instances, but if you > are using ZFS, then shuffling the disks around should not make any > difference. With physical hardware it should be possible to eg. pop the > disks out of one chassis and insert them into another in whatever order, > and the system will still boot correctly. This sounds like the virtual > equivalent of that. > [...] Thanks for the response! Yes, once I have them set up (ZFS or labeled), it doesn't matter what device names they end up having. For now I just do the setup by hand, poking around a bit. Same trick in the Linux world, you end up referring to them by their UUID or .... The tricky bit is the automated setup. Say I ask for two additional devices, "this" and "that". I intend to use "this" for high performance what-cha-macallit so I specify high IOPS and etc.... I intend to use "that" for less important stuff, so I specify "lower" performance. Now as the machine's provisioning itself (e.g. Ansible), how can I reliably decide which to `zpool create` or `glabel` or ... with which names? The Linux world worked around this with the `udev` rules and *etc* that I described earlier. There are hacky ways to work around it, I could ensure that they're different sizes and use that to decide. I could do it in two stages. *etc...* I'm just wondering if there's a way to leverage the bit of info AWS has tucked away for us. g.