From owner-freebsd-questions@freebsd.org Mon Oct 26 01:51:54 2020 Return-Path: Delivered-To: freebsd-questions@mailman.nyi.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mailman.nyi.freebsd.org (Postfix) with ESMTP id DEF4045E448 for ; Mon, 26 Oct 2020 01:51:54 +0000 (UTC) (envelope-from dpchrist@holgerdanske.com) Received: from holgerdanske.com (holgerdanske.com [IPv6:2001:470:0:19b::b869:801b]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange ECDHE (P-256) server-signature RSA-PSS (4096 bits) server-digest SHA256 client-signature RSA-PSS (2048 bits) client-digest SHA256) (Client CN "www.holgerdanske.com", Issuer "www.holgerdanske.com" (not verified)) by mx1.freebsd.org (Postfix) with ESMTPS id 4CKHrT3vPgz4p70 for ; Mon, 26 Oct 2020 01:51:53 +0000 (UTC) (envelope-from dpchrist@holgerdanske.com) Received: from 99.100.19.101 (99-100-19-101.lightspeed.frokca.sbcglobal.net [99.100.19.101]) by holgerdanske.com with ESMTPSA (TLS_AES_128_GCM_SHA256:TLSv1.3:Kx=any:Au=any:Enc=AESGCM(128):Mac=AEAD) (SMTP-AUTH username dpchrist@holgerdanske.com, mechanism PLAIN) for ; Sun, 25 Oct 2020 18:51:45 -0700 Subject: Re: What is the "better / best " method to multi-boot different OSes natively WITHOUT VirtualBox(es) ? To: freebsd-questions@freebsd.org References: <20201024111010.5c867e8540a369b826d26703@sohara.org> <20201025065025.6a13dc89@archlinux> <24469.26288.47199.882303@jerusalem.litteratus.org> <20201025135437.35b592a5@archlinux> <20201025225215.65cfca64@archlinux> From: David Christensen Message-ID: Date: Sun, 25 Oct 2020 18:51:45 -0700 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.12.0 MIME-Version: 1.0 In-Reply-To: <20201025225215.65cfca64@archlinux> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit X-Rspamd-Queue-Id: 4CKHrT3vPgz4p70 X-Spamd-Bar: +++ Authentication-Results: mx1.freebsd.org; dkim=none; dmarc=none; spf=none (mx1.freebsd.org: domain of dpchrist@holgerdanske.com has no SPF policy when checking 2001:470:0:19b::b869:801b) smtp.mailfrom=dpchrist@holgerdanske.com X-Spamd-Result: default: False [3.67 / 15.00]; SUBJECT_ENDS_QUESTION(1.00)[]; RCVD_VIA_SMTP_AUTH(0.00)[]; RCVD_TLS_ALL(0.00)[]; FROM_HAS_DN(0.00)[]; TO_MATCH_ENVRCPT_ALL(0.00)[]; MID_RHS_MATCH_FROM(0.00)[]; MIME_GOOD(-0.10)[text/plain]; TO_DN_NONE(0.00)[]; PREVIOUSLY_DELIVERED(0.00)[freebsd-questions@freebsd.org]; AUTH_NA(1.00)[]; RCPT_COUNT_ONE(0.00)[1]; NEURAL_SPAM_MEDIUM(0.73)[0.728]; ARC_NA(0.00)[]; NEURAL_SPAM_SHORT(0.44)[0.437]; NEURAL_SPAM_LONG(0.60)[0.603]; DMARC_NA(0.00)[holgerdanske.com]; R_SPF_NA(0.00)[no SPF record]; FROM_EQ_ENVFROM(0.00)[]; R_DKIM_NA(0.00)[]; MIME_TRACE(0.00)[0:+]; RCVD_COUNT_TWO(0.00)[2]; ASN(0.00)[asn:6939, ipnet:2001:470::/32, country:US]; MAILMAN_DEST(0.00)[freebsd-questions] X-BeenThere: freebsd-questions@freebsd.org X-Mailman-Version: 2.1.33 Precedence: list List-Id: User questions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 26 Oct 2020 01:51:54 -0000 On 2020-10-25 14:52, Ralf Mardorf wrote: > On Sun, 25 Oct 2020 11:39:48 -0700, David Christensen wrote: >> On 2020-10-25 05:54, Ralf Mardorf wrote: >> Please explain how galvanic isolation relates to electrostatic >> discharge mitigation. > > That's a misunderstanding. > >> Please explain the risk(s) associate with antistatic wrist straps. > > IMO it's a risk for a human being to wear an antistatic wrist strap, > when getting in touch with gear that is connected to the mains. > > IMO if the gear isn't directly connected to the mains, because an > isolating transformer grants galvanic isolation, an antistatic wrist > strap isn't a risk for a human being. > > An antistatic wrist strap protects the gear against static charge, but > might be risky for a human regarding potential equalization, assuming > something should be fishy, such as a hot metal case. Once the human > touches the hot metal case a fault current breaker should detect that > something is missing, but galvanic isolation is way more secure than a > breaker that probably is missing that something is missing. > > Actually the fault current breaker should already do it's job, when the > metal case is hot, already before a human does touch it. If it doesn't, > then touching the metal case might be dangerous with or without > wearing an antistatic wrist strap. > > However, galvanic isolation is absolutely safe, unless getting in > contact with both conductors, which is impossible in our scenario and > even very unlikely when repairing gear. I disagree with several of your points. But, as the subject involves risk and liability, I advise any readers of this thread to hire qualified professionals if they need help with their electrical systems. David