From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from lists.gentoo.org (pigeon.gentoo.org [208.92.234.80]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits)) (No client certificate requested) by finch.gentoo.org (Postfix) with ESMTPS id 316B6158086 for ; Thu, 23 Dec 2021 17:50:41 +0000 (UTC) Received: from pigeon.gentoo.org (localhost [127.0.0.1]) by pigeon.gentoo.org (Postfix) with SMTP id EC4E72BC0B9; Thu, 23 Dec 2021 17:50:33 +0000 (UTC) Received: from mail-oi1-f181.google.com (mail-oi1-f181.google.com [209.85.167.181]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) by pigeon.gentoo.org (Postfix) with ESMTPS id C6E432BC003 for ; Thu, 23 Dec 2021 17:50:32 +0000 (UTC) Received: by mail-oi1-f181.google.com with SMTP id m6so10011342oim.2 for ; Thu, 23 Dec 2021 09:50:32 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to; bh=KVh06wtrn5+S1y59RE2Ag+OhBIPntNOne3Z/C6klvfo=; b=3QbsxJ+ewbw8QSOjblm7v3/AIr42eLdQjnpS/nm2vUHi0xpB+tuG4YVy/iMXvHGfQq 1s4lE+ICeuBP+klYsLw8eP4XNRJurII87EBPLWVzH1PO+nbEr24pVILVXrmYXpyeoUAN l/geE9XzzNLy9Iu8KwZQDdBQTAAuYFAYb9m90ErU2QLnXya5zmVKx+xf6Xz/ZanO1DjM /GNUkV+4GJcv4jV7b60QL/e3h6LZ+2ERxWQ7KIDTp+6NFk0xu/5JWePgpvIBZAj1zRNO 5pjk6ZmEDfOz4PQT/+JGsZ86vO+817T+cedVqu5dZpu8UVXvRaB/uMovw+WnuSCCr1Gl wfKA== X-Gm-Message-State: AOAM530oiO0unE20up8uDH77/Xmk/lOe9z09wsuDxTyeGuJ8sDvswAz3 TgYj3jaJAvl+4dft5hTPv/rCsRLPA0h/yNHH9saVCdbM X-Google-Smtp-Source: ABdhPJxJJhMJCbI61LJ4piT4+bpYAaBKdRrS8MWqX+ZWAzPhUW8HzaA6kFgIvcQboF+ZcgzUY4w+oLSjd0d/mwX/VPQ= X-Received: by 2002:a05:6808:7:: with SMTP id u7mr2422730oic.75.1640281831195; Thu, 23 Dec 2021 09:50:31 -0800 (PST) Precedence: bulk List-Post: List-Help: List-Unsubscribe: List-Subscribe: List-Id: Gentoo Linux mail X-BeenThere: gentoo-user@lists.gentoo.org Reply-to: gentoo-user@lists.gentoo.org X-Auto-Response-Suppress: DR, RN, NRN, OOF, AutoReply MIME-Version: 1.0 References: <04249abe-435d-863f-7246-cd5f438283df@youngman.org.uk> In-Reply-To: From: Rich Freeman Date: Thu, 23 Dec 2021 12:50:20 -0500 Message-ID: Subject: Re: [gentoo-user] Synchronous writes over the network. To: gentoo-user@lists.gentoo.org Content-Type: text/plain; charset="UTF-8" X-Archives-Salt: d4779739-1d2b-467f-ae9a-41cd0900d320 X-Archives-Hash: cc85a89de03bc279ad4a0d7fab92c4ab On Thu, Dec 23, 2021 at 12:39 PM Mark Knecht wrote: > > I'll respond to Rich's points in a bit but on this point I think > you're both right - new SSDs are very very reliable and I'm not overly > worried, but it seems a given that forcing more and more writes to an > SSD has to up the probability of a failure at some point. Zero writes > is almost no chance of failure, trillions of writes eventually wears > something out. > Every SSD has a rating for total writes. This varies and the ones that cost more will get more writes (often significantly more), and wear pattern matters a great deal. Chia fortunately seems to have died off pretty quickly but there is still a ton of data from those who were speculating on it, and they were buying high end SSDs and treating them as expendable resources - and plotting Chia is actually a fairly ideal use case as you write a few hundred GB and then you trim it all when you're done, so the entirety of the drive is getting turned over regularly. People plotting Chia were literally going through cases of high-end SSDs due to write wear, running them until failure in a matter of weeks. Obviously if you just write something and read it back constantly then wear isn't an issue. Just googled the Samsung Evo 870 and they're rated to 600x their capacity in writes, for example. If you write 600TB to the 1TB version of the drive, then it is likely to fail on you not too long after. Sure, it is a lot better than it used to be, and for typical use cases I agree that they last longer than spinning disks. However, a ZIL is not a "typical use case" as such things are measured. -- Rich