From owner-freebsd-hackers@freebsd.org Sat Apr 20 17:52:28 2019 Return-Path: Delivered-To: freebsd-hackers@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 0C418157185D for ; Sat, 20 Apr 2019 17:52:28 +0000 (UTC) (envelope-from mozolevsky@gmail.com) Received: from mail-ot1-f66.google.com (mail-ot1-f66.google.com [209.85.210.66]) (using TLSv1.3 with cipher TLS_AES_128_GCM_SHA256 (128/128 bits) server-signature RSA-PSS (4096 bits) client-signature RSA-PSS (2048 bits) client-digest SHA256) (Client CN "smtp.gmail.com", Issuer "GTS CA 1O1" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id BB2206C7E4; Sat, 20 Apr 2019 17:52:26 +0000 (UTC) (envelope-from mozolevsky@gmail.com) Received: by mail-ot1-f66.google.com with SMTP id s24so6575720otk.13; Sat, 20 Apr 2019 10:52:26 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=bLEfQI8u1xqDgZt/GRXxhi4wxSxtI3daFl+3mLffxoc=; b=TvM0ktefO6VEj6ETyra3NP/5QIx2X9KZ9PRFHpWuynPcSogUT8Celq+Vb2PcOWjGFA tTE59azxDSe/GhRItwff8Mj2UvSNGwWINVsZ9jWD2naKUCw+1VOwuCRQNU0zJcgQKr2+ lGLEexlXDMCLDtBhRQAU1bWQUTL63MgkwpvKLgb5WbPK8aAWY11yzYIwhwuDiv0Wuasq mFZ8O0m3K0pUfkCFDGThl3RulJ+JbIEHrsFJieTyl0JMLWHgGQLVmQSdGxYKzEKTsGNh 8E3pzrwlG+YNxAhcLcq7WmnEFW3RELEnYVqqN3rIbLhApadh3OMgOwsU3tOcHH1+pr6w tKzA== X-Gm-Message-State: APjAAAVBIIglDnnL/G578gOG2VTdhfna4TLwJqd8Zh765tL9aM3ffpmB RJWm4twlq1t58Wo7xRSObCAfs3Z0uysD2EJoB9XaqmDh X-Google-Smtp-Source: APXvYqy65dn9JQ20lLPBdUL4ix1V625edVIIO6Ojs9uwH+rPTUwSQR6dYp4ATU3TNkz3jdMmEMxNqji6qljGn/b0ZOg= X-Received: by 2002:a9d:6ace:: with SMTP id m14mr5873219otq.296.1555782353219; Sat, 20 Apr 2019 10:45:53 -0700 (PDT) MIME-Version: 1.0 References: <2006ff8da153bbe5e7f620da9260ee1518bd248f.camel@freebsd.org> In-Reply-To: From: Igor Mozolevsky Date: Sat, 20 Apr 2019 18:45:17 +0100 Message-ID: Subject: Re: bhyve VM stopped to boot after moving virtio disks To: Ian Lepore Cc: Hackers freeBSD Content-Type: text/plain; charset="UTF-8" X-Rspamd-Queue-Id: BB2206C7E4 X-Spamd-Bar: --- Authentication-Results: mx1.freebsd.org; spf=pass (mx1.freebsd.org: domain of mozolevsky@gmail.com designates 209.85.210.66 as permitted sender) smtp.mailfrom=mozolevsky@gmail.com X-Spamd-Result: default: False [-3.42 / 15.00]; ARC_NA(0.00)[]; NEURAL_HAM_MEDIUM(-1.00)[-0.998,0]; FROM_HAS_DN(0.00)[]; RWL_MAILSPIKE_GOOD(0.00)[66.210.85.209.rep.mailspike.net : 127.0.0.18]; R_SPF_ALLOW(-0.20)[+ip4:209.85.128.0/17]; TO_MATCH_ENVRCPT_ALL(0.00)[]; MIME_GOOD(-0.10)[text/plain]; RCVD_TLS_LAST(0.00)[]; DMARC_NA(0.00)[hybrid-lab.co.uk]; NEURAL_HAM_LONG(-1.00)[-1.000,0]; IP_SCORE(-1.24)[ipnet: 209.85.128.0/17(-3.88), asn: 15169(-2.26), country: US(-0.06)]; TO_DN_ALL(0.00)[]; MX_GOOD(-0.01)[cached: alt3.gmail-smtp-in.l.google.com]; RCPT_COUNT_TWO(0.00)[2]; RCVD_IN_DNSWL_NONE(0.00)[66.210.85.209.list.dnswl.org : 127.0.5.0]; NEURAL_HAM_SHORT(-0.17)[-0.169,0]; FORGED_SENDER(0.30)[igor@hybrid-lab.co.uk,mozolevsky@gmail.com]; MIME_TRACE(0.00)[0:+]; R_DKIM_NA(0.00)[]; FREEMAIL_ENVFROM(0.00)[gmail.com]; ASN(0.00)[asn:15169, ipnet:209.85.128.0/17, country:US]; FROM_NEQ_ENVFROM(0.00)[igor@hybrid-lab.co.uk,mozolevsky@gmail.com]; RCVD_COUNT_TWO(0.00)[2] X-BeenThere: freebsd-hackers@freebsd.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Technical Discussions relating to FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sat, 20 Apr 2019 17:52:28 -0000 On Sat, 20 Apr 2019 at 18:00, Ian Lepore wrote: > dd absolutely will fail to copy the last block of the source if it > isn't exactly the blocksize and you didn't specify conv=sync, and it > will return a zero status when doing so. It appears you've convinced > yourself otherwise, but for anyone else reading this thread, be aware: > conv=sync is required to copy the last part of the source if it's > smaller than the blocksize. Isn't that contrary to the POSIX Spec? Reading the manual [1], it is implied (from STDERR part of the main section) that dd will read and write partial blocks, cf. truncated blocks?.. 1. https://pubs.opengroup.org/onlinepubs/9699919799/utilities/dd.html -- Igor M.