From nobody Tue Jan 11 10:02:26 2022 X-Original-To: questions@mlmmj.nyi.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mlmmj.nyi.freebsd.org (Postfix) with ESMTP id F1BC9193C482 for ; Tue, 11 Jan 2022 10:04:50 +0000 (UTC) (envelope-from hruodr@gmail.com) Received: from mail-wr1-x42a.google.com (mail-wr1-x42a.google.com [IPv6:2a00:1450:4864:20::42a]) (using TLSv1.3 with cipher TLS_AES_128_GCM_SHA256 (128/128 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256 client-signature RSA-PSS (2048 bits) client-digest SHA256) (Client CN "smtp.gmail.com", Issuer "GTS CA 1D4" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id 4JY5sG1JlKz4hwb for ; Tue, 11 Jan 2022 10:04:50 +0000 (UTC) (envelope-from hruodr@gmail.com) Received: by mail-wr1-x42a.google.com with SMTP id v6so31838701wra.8 for ; Tue, 11 Jan 2022 02:04:50 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=date:from:to:subject:message-id:mime-version; bh=W5raZ3aK/LkEGm+1Gp8Q9VVyw3x3WbwF3t8MnbiYpoE=; b=pR2+tEoqnKpwzDQBdmNVuYJ7h+y4Zmjn7EEK/DRIl+g/8jzzSMl+evUzXGGplTcock ej5eJ02l8bscAIGXftVLq8RsaOpaKG7wrwbb1W1wErabfyGGcz1MxXFgP0c8PNgxVFWW 2CIPZYFE+g7h6lFBhnkVWsW58D85Bq/gk6WthxBg3pZCFederecBgjBDGU7Gzxs8pSns ZnhlPnQIST3/+XZFe0XoTVPSH902M/p8UDZohHgEfrTfaNeOgfUzzim2G8QC7llt6D4Q rKjEh5Ecdg1zWqUZVeBAt+qbMvjJ5Zo/wA+Cdm5yqmov3npwzXjWc17ZWilJTxDx4LRf a5Wg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:date:from:to:subject:message-id:mime-version; bh=W5raZ3aK/LkEGm+1Gp8Q9VVyw3x3WbwF3t8MnbiYpoE=; b=L/NMqsYHBGV9bTvZIRRAXDFK2KeKsHJCUnc4ShEjRsC40kR83t9sKVsNi4zIijtgZM 26qlFJlOEcD9RxpBkggQdewNfg06ozjdheTTrd1XgYH8+YQ6kATtyWaxVRbSrSJfimMq SILzauZWAYKwnGOsT/8WT0CgWXh45q6gCRnKnAtetUr61ROR4vMiMo3fhq7qIB591fe2 ZGNx+lonjSCCA8YkVecLuq1m0JCCqGoD9zL8saShvv2nmqLufiua5r4HK3uAe3XfeueL ZI7nIU2aOU02TUIAipizrUqi7lvffm3PfpnbrJzZprEuVL43fWsTDJpoo2A6KbEXJyJU pQjA== X-Gm-Message-State: AOAM530jjYIKN7tFAuKMD0DcdINJLVOZ/4TwWNiA3pY4dZ4UNWLhAKol BK+nop9Mhk6LUx5Hl8pW3lD76rbH1e0= X-Google-Smtp-Source: ABdhPJwjh24SllfBTlfRCxSETPbHLtLm4z05uJ7KrYg3hZjbqtYta8JQG123Qa1o3K2dNHEB3xD2RA== X-Received: by 2002:a5d:6488:: with SMTP id o8mr3099654wri.576.1641895489101; Tue, 11 Jan 2022 02:04:49 -0800 (PST) Received: from [192.168.178.26] (dslb-188-102-039-035.188.102.pools.vodafone-ip.de. [188.102.39.35]) by smtp.gmail.com with ESMTPSA id h20sm1335659wmq.38.2022.01.11.02.04.48 for (version=TLS1_2 cipher=ECDHE-ECDSA-AES128-GCM-SHA256 bits=128/128); Tue, 11 Jan 2022 02:04:48 -0800 (PST) Date: Tue, 11 Jan 2022 10:02:26 +0000 (UTC) From: Roderick To: questions@freebsd.org Subject: dd and mbr Message-ID: <4af920fc-eff1-a92e-d36e-1ba97079864c@gmail.com> List-Id: User questions List-Archive: https://lists.freebsd.org/archives/freebsd-questions List-Help: List-Post: List-Subscribe: List-Unsubscribe: Sender: owner-freebsd-questions@freebsd.org X-BeenThere: freebsd-questions@freebsd.org MIME-Version: 1.0 Content-Type: text/plain; format=flowed; charset=US-ASCII X-Rspamd-Queue-Id: 4JY5sG1JlKz4hwb X-Spamd-Bar: -- Authentication-Results: mx1.freebsd.org; dkim=pass header.d=gmail.com header.s=20210112 header.b=pR2+tEoq; dmarc=pass (policy=none) header.from=gmail.com; spf=pass (mx1.freebsd.org: domain of hruodr@gmail.com designates 2a00:1450:4864:20::42a as permitted sender) smtp.mailfrom=hruodr@gmail.com X-Spamd-Result: default: False [-2.06 / 15.00]; RCVD_VIA_SMTP_AUTH(0.00)[]; FREEMAIL_FROM(0.00)[gmail.com]; R_SPF_ALLOW(-0.20)[+ip6:2a00:1450:4000::/36]; TO_DN_NONE(0.00)[]; RCVD_COUNT_THREE(0.00)[3]; DKIM_TRACE(0.00)[gmail.com:+]; DMARC_POLICY_ALLOW(-0.50)[gmail.com,none]; NEURAL_HAM_SHORT(-1.00)[-1.000]; RECEIVED_SPAMHAUS_PBL(0.00)[188.102.39.35:received]; FROM_EQ_ENVFROM(0.00)[]; MIME_TRACE(0.00)[0:+]; FREEMAIL_ENVFROM(0.00)[gmail.com]; ASN(0.00)[asn:15169, ipnet:2a00:1450::/32, country:US]; MID_RHS_MATCH_FROM(0.00)[]; DWL_DNSWL_NONE(0.00)[gmail.com:dkim]; ARC_NA(0.00)[]; NEURAL_HAM_MEDIUM(-1.00)[-1.000]; R_DKIM_ALLOW(-0.20)[gmail.com:s=20210112]; FROM_HAS_DN(0.00)[]; TO_MATCH_ENVRCPT_ALL(0.00)[]; MIME_GOOD(-0.10)[text/plain]; PREVIOUSLY_DELIVERED(0.00)[questions@freebsd.org]; RCPT_COUNT_ONE(0.00)[1]; NEURAL_SPAM_LONG(0.94)[0.938]; RCVD_IN_DNSWL_NONE(0.00)[2a00:1450:4864:20::42a:from]; RCVD_TLS_ALL(0.00)[] X-ThisMailContainsUnwantedMimeParts: N The command: dd if=/dev/zero of=/dev/da0 does not delete the mbr, I still see the partition table with fdisk. My questions: (1) What does this command do? (2) How to delete the mbr with dd? How to address the whole disk with dd? In OpenBSD is simply dd if=/dev/zero of=/dev/rsd0c with perhaps a count argument. Rod.