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=DKIM_SIGNED,DKIM_VALID, MAILING_LIST_MULTI,RCVD_IN_DNSWL_NONE autolearn=ham autolearn_force=no version=3.4.4 Received: (qmail 14030 invoked from network); 10 Dec 2020 03:11:08 -0000 Received: from minnie.tuhs.org (45.79.103.53) by inbox.vuxu.org with ESMTPUTF8; 10 Dec 2020 03:11:08 -0000 Received: by minnie.tuhs.org (Postfix, from userid 112) id 7435293D5B; Thu, 10 Dec 2020 13:11:06 +1000 (AEST) Received: from minnie.tuhs.org (localhost [127.0.0.1]) by minnie.tuhs.org (Postfix) with ESMTP id D257093D34; Thu, 10 Dec 2020 13:10:35 +1000 (AEST) Authentication-Results: minnie.tuhs.org; dkim=pass (2048-bit key; unprotected) header.d=algebras-org.20150623.gappssmtp.com header.i=@algebras-org.20150623.gappssmtp.com header.b="N5z2dBM9"; dkim-atps=neutral Received: by minnie.tuhs.org (Postfix, from userid 112) id 842E993D34; Thu, 10 Dec 2020 13:10:32 +1000 (AEST) Received: from mail-pf1-f175.google.com (mail-pf1-f175.google.com [209.85.210.175]) by minnie.tuhs.org (Postfix) with ESMTPS id 779AC93D28 for ; Thu, 10 Dec 2020 13:10:30 +1000 (AEST) Received: by mail-pf1-f175.google.com with SMTP id t7so2689634pfh.7 for ; Wed, 09 Dec 2020 19:10:30 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=algebras-org.20150623.gappssmtp.com; s=20150623; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :content-transfer-encoding; bh=OeM+zL5CwvHygqwJyxt/dfNT4Vfkh3UUZxCIoqR+neU=; b=N5z2dBM9LS6yP0go1D4WVmGQR2B/R7jOeOZfeY0g+eKxQ7EeRiB9lDbr5SKtGgLbQR LhzVgsFkFyyjgmt131T2/JwTC2LB4H1m9qZTQGf/D55e3ECl7m7XjHUhxbDovM9/zynh 7sNbEg3/bN1X7OmMsOJBogjG/XMY2sUJXWhd9+Or+GVNcGRn0Xqtgfp3BzMDK5sQr6QP wo/gXzUK3sC/5PXAiBpmMKhzocKZldQACTHQlqEBqVgFSM2sOz3Wv1ay33AaSRky3Nii PWBUipnKAMNjLHxd7Me2RmzEVo0+adag86ax8oGJLF28vHpJ+kbNM+1WzKdl85YxDCMp 1/rw== 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:content-transfer-encoding; bh=OeM+zL5CwvHygqwJyxt/dfNT4Vfkh3UUZxCIoqR+neU=; b=j1CCXervYdJEszkxGUkf/DTD+WHavVMxIuk1P9V4D552q3ahWAikPFNS6yrq/7CzE/ WlHNPoF2WnpP51dCM1iex7K32SdHVKl9C9o5dctW9qcE5+3+eG1dBPx/jcICJ7gHapOm VrKxI7zsI7lTpEKn3GTML9WV9eNkTAcJ62iN+YGEns82c9hYQjEH4DmbVu6dbmeH8P3+ /QiBwnXKOpSnbPAfIHpRbJx20E9jOCDRqxKHUQ2pnc89JwlWBXuuvtFDQpcEBe6VvDXb Dpv3LfcAN9VOvrrD3VOxE2kzbFYm1Pv4+/nNYOqqiT8bWDTUJcGmjmOoPF47/WJaKhSn afCA== X-Gm-Message-State: AOAM533+iCgT2rQXUxggf1ekZHpQvDbNMC3CL9h7NDNGS2mnsV68dn5V t+j5HvqNQrFNFr0OyM6XkCG3CM08WNHjrYDYndKVor6k1zAhsfl3 X-Google-Smtp-Source: ABdhPJyIIZ+vHOOV+4NfNOhJQchTPyTEAScbS5DcT/iS/Ku6IDzhwTOAjd9ZOtE5Xf+RXeEbVPv8FW3XeAdRDCnkkkE= X-Received: by 2002:a17:90a:315:: with SMTP id 21mr3641174pje.25.1607569829593; Wed, 09 Dec 2020 19:10:29 -0800 (PST) MIME-Version: 1.0 References: <1479.1607559546@hop.toad.com> <20201210002916.GH3303@mcvoy.com> <28537.1607561596@cesium.clock.org> In-Reply-To: <28537.1607561596@cesium.clock.org> From: George Michaelson Date: Thu, 10 Dec 2020 13:10:18 +1000 Message-ID: To: The Eunuchs Hysterical Society Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable Subject: Re: [TUHS] Cole's Slaw 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" I deployed cheap switches, to try and reduce contention on the WiFi segment in a 3bed flat. I suspect, switching is *slower* than good quality 4/5G. I deployed cheap unmanaged switches. I think I may need to re-consider. (it may be slower than good quality 5gz WIFi but I felt not, lots of concrete, so I went cables in walls. Professionally installed cables too) old cheap switches have high port speed, but low cross-backplane bandwidth. They basically don't do what they say on the label although I have no proof, my observation is that 100mbit is rarely achieved on a cheap switching backplane. I think most people won't notice. If you need to do the full-disk restore, or stream 4K at the same time as play some call-of-duty *and* do a full-disk streaming restore, I think you can destroy your cheap home switch quickly. I have been prepping a ZFS filestore and I calculate I'm getting 30mbit-sec end-to-end from 300mbit capable backplane hosts. The port speeds are gig. The actual capability once you get over the Raspberry Pi USB3 is a LOT less. (the receiver is a Pi4 with 8GB of memory, it should *not* be disk I/O bound) my various OSX Macs can do roaring speeds if you back-to-back connect them. Put them into the switching stuff, it drops off really quickly to boringly slow speeds. If you go out the fibre router to the public network, I think their contention model remains interesting: Stuff is being done in layer 2 to manage your bandwidth and the fibre which is capable of gig, is probably doing bizarre things to pretend to be slower. Forced bit-drop, random drop, long stalls. The framing at layer2 is really bizarre. they can do a LOT in layer 2, they don't talk about. we're all some kind of PPPo inside this, which feels pretty meh. Why did it have to be like this? Economies which (unlike Australia) don't do bandwidth limit for pricing disfunction, probably are saying :what do you mean: at this point. (The UK, you can get true gig to the home. Parts of the USA likewise. Lots of europe likewise. Here in Oz, although the bearer is capable, you can't afford the price they want to charge because they'd doing ROI sums to pay back $50b of spend, as quickly as possible) If your router is running the Broadcom chipset most of them are built around, Its switch is not really very big, in buffer space. My R7000 is a Broadcom BCM4709A0 and I don't think its doing very well. So, I'm dying inside because this is highly contestable FUD. If somebody with shares in the vendors chipset can tell me "you're just wrong' I'd believe them but my experience from the field is, white box domestic switches, and home routers, simply can't "do" full-bore gig on multiple paths across the switch at once. Ubiquity and other good vendors? Probably fine. Hell, for all I know, even Mikrotik might be ok, I've only ever had their toss-away freebies from conference Schwag and it was cool to have a box the size of a packet of cigarettes which run BGP, but they felt pretty slow (they even do portspan. amazing stuff) -G On Thu, Dec 10, 2020 at 10:53 AM Erik E. Fair wrote: > > I bet your backups across the gigabit switch to your NAS are (small) incr= ementals. > > You'll care about having 10gigE when you try a restore from backup. > > We have a very persistent problem with storage capacity versus I/O bandwi= dth, which I metaphor as "swimming pools of data, which we fill & drain wit= h garden hoses." How many terabytes of stable storage do you have at home? > > Further, LANs have always lagged local I/O bandwidth (across PCI, PCIe, e= tc), independent of the nastiness introduced by latency and less-than-ideal= data transfer protocols. Unix "diskless" workstations were only tolerable = because the disks were still expensive and there were good reasons to share= . > > Erik