From owner-freebsd-cloud@freebsd.org Thu Nov 3 18:31:59 2016 Return-Path: Delivered-To: freebsd-cloud@mailman.ysv.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:1900:2254:206a::19:1]) by mailman.ysv.freebsd.org (Postfix) with ESMTP id 5EDF1C2E35D for ; Thu, 3 Nov 2016 18:31:59 +0000 (UTC) (envelope-from newt0311@gmail.com) Received: from mail-ua0-x232.google.com (mail-ua0-x232.google.com [IPv6:2607:f8b0:400c:c08::232]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (Client CN "smtp.gmail.com", Issuer "Google Internet Authority G2" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id 1D3531971 for ; Thu, 3 Nov 2016 18:31:59 +0000 (UTC) (envelope-from newt0311@gmail.com) Received: by mail-ua0-x232.google.com with SMTP id b35so46946783uaa.3 for ; Thu, 03 Nov 2016 11:31:59 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=mime-version:from:date:message-id:subject:to; bh=WU8mRWbvNFjeZxH2yhQje5pZd2tTZ2nOoNsv2n69Uw8=; b=cp/2ZqjUAmxNk4moXDaGrsf5lBtpnYZTuH2QmD8b1uTqM5D+8BdN5sLCa3vJeJXwsq xtNTWtjI0LxwhKhmGyV5NYSLQM6aCuzViY8kLBlf1VTcEzObx1Q5AT0L/2oqtmTauJNq yzTPxb8lf4GuO8y5c6RLSGIUjZyudGUmfk2Rnle1l7opN/esSjt6Zf9yavCZqJyBcMOY m9jsM1snw6yQk2u1n/sLI5+4p/rTH3kpKlsx7CX0nfPHVHdKlCxqm+TXxICWzWn8bb/2 t/Lqf6AgSa7Z8JKwlqtHNZ6jEGBGshYGJjKtj9UHzgPd/FCIlArceXi2A1Xigd6ssQ9K ysRQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20130820; h=x-gm-message-state:mime-version:from:date:message-id:subject:to; bh=WU8mRWbvNFjeZxH2yhQje5pZd2tTZ2nOoNsv2n69Uw8=; b=TZ8u07PynXIZp53g2nAdeRoi8zKtP92pLR7SQGsI6sQoqkdWG8aufDFNRjywENRzb6 Bpu3+7wvkfGRjShRORWPN2RX+5fs+l5Y/qAGA6DZk9zoYkiRVq89qFwgjRLX8AYVsu9V vEeRINgTzbp9B1ySt9DOEZNRY/NbD6+qSRqYVlGesykpmPyDdm/ywYjFCrqEbykCXU7V agmZC5SQF3SnpwfTN9+Esgs8uvYavWJ/++jdy3R5Wbb7LiUrwOgWop5frP1Mn61A7fm/ yYeFHTR8RCzCtF8wClo7UJSH1qqXuXpaXUNjs/1ujlstBd3bYbtEBwi1vMRKDdunHhKJ RSVA== X-Gm-Message-State: ABUngvfqDsEXGDh+s8jYdoV0GNnDKbx/RhQueAFeKSuFB5E5caHjp9LaV0wQNAd7G7QSqsd6ejuj9pMlXsHHzg== X-Received: by 10.159.49.27 with SMTP id m27mr8729425uab.178.1478197918026; Thu, 03 Nov 2016 11:31:58 -0700 (PDT) MIME-Version: 1.0 Received: by 10.103.69.19 with HTTP; Thu, 3 Nov 2016 11:31:37 -0700 (PDT) From: Prakhar Goel Date: Thu, 3 Nov 2016 14:31:37 -0400 Message-ID: Subject: FreeBSD images swap space on GCE To: freebsd-cloud@freebsd.org Content-Type: text/plain; charset=UTF-8 X-BeenThere: freebsd-cloud@freebsd.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: "FreeBSD on cloud platforms \(EC2, GCE, Azure, etc.\)" List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 03 Nov 2016 18:31:59 -0000 Hello, Something I came across recently: I'm using freebsd-11-0-release-amd64 from the freebsd-org-cloud-dev for some of my VMs. Under high memory pressure they seem to just lock up and become unresponsive. I've waited for up to ~15 minutes for them to revive with no luck. After a little debugging, I think I've narrowed the problem down to the swap space. By default, the VM seems to have a 1GB swap space setup on the root disk. GCE scales I/O linearly with the size of the disk and the size of the root disk is only 22GB. I think this leaves the root disk with too little I/O capacity to act as swap space (it's still enough for normal fs use apparently). When I was monitoring this in top, my memory-intensive processes would continue to work until the system ran out of RAM and then they'd just get stuck in "vmwait." To resolve the problem, I enabled extra space in an attached volume (standard persistent disk, 200GB size). As long as my new swap space was enabled *and the old swap space was disabled*, my applications were fine. Not sure what can be done to resolve this. The default swap setup just seems to cause problems so maybe remove it altogether and let users set up their own swap space on faster devices as needed? Thanks. PS. Is this the right place to send emails like this? Not sure myself. -- ________________________ Warm Regards Prakhar Goel