From mboxrd@z Thu Jan 1 00:00:00 1970 X-Spam-Checker-Version: SpamAssassin 3.4.4 (2020-01-24) on inbox.vuxu.org X-Spam-Level: X-Spam-Status: No, score=-1.0 required=5.0 tests=MAILING_LIST_MULTI autolearn=ham autolearn_force=no version=3.4.4 Received: (qmail 3744 invoked from network); 2 Sep 2021 15:52:57 -0000 Received: from minnie.tuhs.org (45.79.103.53) by inbox.vuxu.org with ESMTPUTF8; 2 Sep 2021 15:52:57 -0000 Received: by minnie.tuhs.org (Postfix, from userid 112) id E751B9C223; Fri, 3 Sep 2021 01:52:54 +1000 (AEST) Received: from minnie.tuhs.org (localhost [127.0.0.1]) by minnie.tuhs.org (Postfix) with ESMTP id 3358E9BA1D; Fri, 3 Sep 2021 01:52:29 +1000 (AEST) Received: by minnie.tuhs.org (Postfix, from userid 112) id 415AC9BA1D; Fri, 3 Sep 2021 01:52:26 +1000 (AEST) Received: from darkstar.fourwinds.com (fourwinds.com [63.64.179.162]) by minnie.tuhs.org (Postfix) with ESMTPS id 7623D9B9F9 for ; Fri, 3 Sep 2021 01:52:24 +1000 (AEST) Received: from darkstar.fourwinds.com (localhost [127.0.0.1]) by darkstar.fourwinds.com (8.16.1/8.15.2) with ESMTP id 182FqNBm3750788 for ; Thu, 2 Sep 2021 08:52:23 -0700 Received: from darkstar.fourwinds.com (jon@localhost) by darkstar.fourwinds.com (8.16.1/8.15.2/Submit) with ESMTP id 182FqNLB3750785 for ; Thu, 2 Sep 2021 08:52:23 -0700 Message-Id: <202109021552.182FqNLB3750785@darkstar.fourwinds.com> From: Jon Steinhart To: The Unix Heretics Society mailing list In-reply-to: <71B14DD4-0F7D-4AE1-9BCE-3327C056FFD2@iitbombay.org> References: <202108292212.17TMCGow1448973@darkstar.fourwinds.com> <20210829235745.GC20021@mcvoy.com> <71B14DD4-0F7D-4AE1-9BCE-3327C056FFD2@iitbombay.org> Comments: In-reply-to Bakul Shah message dated "Mon, 30 Aug 2021 16:04:26 -0700." MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-ID: <3750783.1630597943.1@darkstar.fourwinds.com> Date: Thu, 02 Sep 2021 08:52:23 -0700 X-JON-SPAM: local delivery Subject: Re: [TUHS] Is it time to resurrect the original dsw (delete with switches)? X-BeenThere: tuhs@minnie.tuhs.org X-Mailman-Version: 2.1.26 Precedence: list List-Id: The Unix Heritage Society mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: tuhs-bounces@minnie.tuhs.org Sender: "TUHS" Hey, wanted to thank everybody for the good information on this topic. Was pleasantly surprised that we got through it without a flame war :-) I have a related question in case any of you have actual factual knowledge of disk drive internals. A friend who used to be in charge of reliability engineering at Seagate used to be a great resource but he's now retired. For example, years ago someone ranted at me about disk manufacturers sacrificing reliability to save a few pennies by removing the head ramp; I asked my friend who explained to me how that ramp was removed to improve reliability. So my personal setup here bucks conventional wisdom in that I don't do RAID. One reason is that I read the Google reliability studies years ago and interpreted them to say that if I bought a stack of disks on the same day I could expect them to fail at about the same time. Another reason is that 24x7 spinning disk drives is the biggest power consumer in my office. Last reason is that my big drives hold media (music/photos/video), so if one dies it's not going to be any sort of critical interruption. My strategy is to keep three (+) copies. I realized that I first came across this wisdom while learning both code and spelunking as a teenager from Carl Christensen and Heinz Lycklama in the guise of how many spare headlamps one should have when spelunking. There's the copy on my main machine, another in a fire safe, and I rsync to another copy on a duplicate machine up at my ski condo. Plus, I keep lots of old fragments of stuff on retired small (<10T) disks that are left over from past systems. And, a lot of the music part of my collection is backed up by proof-of-purchase CDs in the store room or shared with many others so it's not too hard to recover. Long intro, on to the question. Anyone know what it does to reliability to spin disks up and down. I don't really need the media disks to be constantly spinning; when whatever I'm listening to in the evening finishes the disk could spin down until morning to save energy. Likewise the video disk drive is at most used for a few hours a day. My big disks (currently 16T and 12T) bake when they're spinning which can't be great for them, but I don't know how that compares to mechanical stress from spinning up and down from a reliability standpoint. Anyone know? Jon