Re: Server hardware advice.

From	David Christensen <dpchrist@holgerdanske.com>
Newsgroups	linux.debian.user
Subject	Re: Server hardware advice.
Date	2019-08-09 00:10 +0200
Message-ID	<ysYLE-2xg-7@gated-at.bofh.it> (permalink)
References	<ysmQ1-3Sj-1@gated-at.bofh.it> <ysKIF-28K-7@gated-at.bofh.it> <ysQXL-5Rz-1@gated-at.bofh.it> <ysRAt-6kT-1@gated-at.bofh.it>
Organization	linux.* mail to news gateway

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On 8/8/19 7:22 AM, Dan Ritter wrote:
> To summarize: if you're running ZFS, it can protect you from
> lots of sources of data corruption. It can't protect you from
> RAM errors without ECC, so you should opt for ECC if integrity
> is your goal.
>
> None of the other filesystems protect you against RAM errors
> either, so this is not a special requirement of ZFS.

+1

The same goes for anything that uses main memory, which is pretty much 
everything I use computers for.

Bad data in memory is bad enough, but bad data written to disk is the 
gift that keeps on giving -- replication overwriting good data, snapshot 
and backup rotation overwriting good data, archive destruction 
destroying good data, etc..  The longer it takes to figure out the data 
is bad, the less likely you can recover.

For me, the key points in favor of ECC are:

1. Wikipedia gives DRAM bit error rates (BER) from 10E-10 to 10E-17 
errors per bit per hour [1].  So, 1 error per year for 114 kB to 1.14 TB 
of DRAM on average under some test conditions.

2.  In the wild, not all chips, modules, sockets, capacitors, 
motherboards, etc., are healthy or compatible.  Real BER's can be much 
higher.

3.  The BER of DRAM tends to increase as the transistors, capacitors, 
lines, etc., get smaller and faster [2].  Given Moore's Law, 
manufacturers must be hard pressed just to maintain the BER with each 
new generation.

4.  Moore's Law again: the amount of DRAM in devices has been increasing 
exponentially, thus adding more DRAM that can error.

So, it is just a matter of time before the error probability curve 
crosses the BER specification.  One article I read said desktops and 
laptops already crossed it at 8 to 16 GB.  COTS servers can have one or 
two orders of magnitude more memory.

David

[1] https://en.wikipedia.org/wiki/Dynamic_random-access_memory

[2] https://danluu.com/why-ecc/

Thread

Server hardware advice. Steven Mainor <steve@degga.net> - 2019-08-07 07:40 +0200
  Re: Server hardware advice. Richard Hector <richard@walnut.gen.nz> - 2019-08-07 08:00 +0200
    Re: Server hardware advice. Steven Mainor <steve@degga.net> - 2019-08-07 08:10 +0200
      Re: Server hardware advice. Nektarios Katakis <nektarios@mail.nektarioskatakis.xyz> - 2019-08-07 12:20 +0200
        Re: Server hardware advice. mick crane <mick.crane@gmail.com> - 2019-08-07 14:10 +0200
      Re: Server hardware advice. deloptes <deloptes@gmail.com> - 2019-08-07 17:00 +0200
        Re: Server hardware advice. Michael Stone <mstone@debian.org> - 2019-08-07 17:10 +0200
          Re: Server hardware advice. deloptes <deloptes@gmail.com> - 2019-08-07 17:20 +0200
            Re: Server hardware advice. Michael Stone <mstone@debian.org> - 2019-08-07 17:40 +0200
            Re: Server hardware advice. ghe <ghe@slsware.net> - 2019-08-07 17:50 +0200
            Re: Server hardware advice. Celejar <celejar@gmail.com> - 2019-08-08 00:20 +0200
        Re: Server hardware advice. Steven Mainor <steve@degga.net> - 2019-08-07 18:50 +0200
          Re: Server hardware advice. deloptes <deloptes@gmail.com> - 2019-08-08 07:50 +0200
            Helpful attitude (was: Server hardware advice.) Nicolas George <george@nsup.org> - 2019-08-08 11:00 +0200
              Re: Helpful attitude (was: Server hardware advice.) Kenneth Parker <sea7kenp@gmail.com> - 2019-08-08 12:50 +0200
                Re: Helpful attitude (was: Server hardware advice.) Jonas Smedegaard <jonas@jones.dk> - 2019-08-08 14:10 +0200
                Re: Helpful attitude (was: Server hardware advice.) Dan Ritter <dsr@randomstring.org> - 2019-08-08 16:20 +0200
                Re: Helpful attitude (was: Server hardware advice.) Jonas Smedegaard <jonas@jones.dk> - 2019-08-08 17:00 +0200
                Re: Helpful attitude (was: Server hardware advice.) deloptes <deloptes@gmail.com> - 2019-08-08 17:20 +0200
                Re: Helpful attitude (was: Server hardware advice.) Jonas Smedegaard <jonas@jones.dk> - 2019-08-08 18:00 +0200
                Re: Helpful attitude (was: Server hardware advice.) Judah Richardson <judahrichardson@gmail.com> - 2019-08-08 21:50 +0200
                Re: Helpful attitude (was: Server hardware advice.) deloptes <deloptes@gmail.com> - 2019-08-09 00:50 +0200
                [OT] Helpful attitude (was: Server hardware advice.) <tomas@tuxteam.de> - 2019-08-09 10:00 +0200
                Re: [OT] Helpful attitude (was: Server hardware advice.) Étienne Mollier <etienne.mollier@mailoo.org> - 2019-08-09 11:20 +0200
                Re: [OT] Helpful attitude (was: Server hardware advice.) <tomas@tuxteam.de> - 2019-08-09 11:50 +0200
                Re: [OT] Helpful attitude (was: Server hardware advice.) Étienne Mollier <etienne.mollier@mailoo.org> - 2019-08-09 12:30 +0200
                Re: [OT] Helpful attitude (was: Server hardware advice.) tomas@tuxteam.de - 2019-08-09 14:40 +0200
                Re: [OT] Helpful attitude (was: Server hardware advice.) Étienne Mollier <etienne.mollier@mailoo.org> - 2019-08-09 15:50 +0200
                Re: [OT] Helpful attitude John Hasler <jhasler@newsguy.com> - 2019-08-09 15:50 +0200
                Re: [OT] Helpful attitude The Wanderer <wanderer@fastmail.fm> - 2019-08-09 16:00 +0200
                Re: [OT] Helpful attitude Larry Martell <larry.martell@gmail.com> - 2019-08-09 16:10 +0200
                Re: [OT] Helpful attitude Étienne Mollier <etienne.mollier@mailoo.org> - 2019-08-09 16:10 +0200
                Re: [OT] Helpful attitude John Hasler <jhasler@newsguy.com> - 2019-08-09 17:30 +0200
                Re: [OT] Helpful attitude Étienne Mollier <etienne.mollier@mailoo.org> - 2019-08-09 19:00 +0200
                Re: [OT] Helpful attitude deloptes <deloptes@gmail.com> - 2019-08-09 18:30 +0200
                Re: [OT] Helpful attitude Brian <ad44@cityscape.co.uk> - 2019-08-09 20:50 +0200
                Re: Helpful attitude (was: Server hardware advice.) Curt <curty@free.fr> - 2019-08-08 22:20 +0200
                Re: Helpful attitude Richard Owlett <rowlett@cloud85.net> - 2019-08-09 16:10 +0200
                Re: Helpful attitude (was: Server hardware advice.) ghe <ghe@slsware.net> - 2019-08-09 08:20 +0200
                Re: Helpful attitude (was: Server hardware advice.) Gene Heskett <gheskett@shentel.net> - 2019-08-09 09:20 +0200
                Re: Helpful attitude (was: Server hardware advice.) "Bob Crochelt" <rfc56@fastmail.com> - 2019-08-09 14:00 +0200
                Re: Helpful attitude (was: Server hardware advice.) Gene Heskett <gheskett@shentel.net> - 2019-08-09 16:20 +0200
                Re: Helpful attitude (was: Server hardware advice.) "Bob Crochelt" <rfc56@fastmail.com> - 2019-08-10 00:00 +0200
              Re: Helpful attitude (was: Server hardware advice.) rhkramer@gmail.com - 2019-08-08 14:10 +0200
  Re: Server hardware advice. Reco <recoverym4n@enotuniq.net> - 2019-08-07 09:00 +0200
    Re: Server hardware advice. john doe <johndoe65534@mail.com> - 2019-08-07 09:40 +0200
      Re: Server hardware advice. Jonas Smedegaard <jonas@jones.dk> - 2019-08-07 10:50 +0200
    Re: Server hardware advice. Jonas Smedegaard <jonas@jones.dk> - 2019-08-07 10:30 +0200
      Re: Server hardware advice. Reco <recoverym4n@enotuniq.net> - 2019-08-07 11:00 +0200
        Re: Server hardware advice. Jonas Smedegaard <jonas@jones.dk> - 2019-08-07 11:10 +0200
      Re: Server hardware advice. Steven Mainor <steve@degga.net> - 2019-08-07 12:10 +0200
        Re: Server hardware advice. Jonas Smedegaard <jonas@jones.dk> - 2019-08-07 12:50 +0200
      Re: Server hardware advice. jochen-2019-q2@ozark.de - 2019-08-07 22:40 +0200
      Re: Server hardware advice. Andrei POPESCU <andreimpopescu@gmail.com> - 2019-08-08 09:30 +0200
        Re: Server hardware advice. John Hasler <jhasler@newsguy.com> - 2019-08-09 05:20 +0200
          Re: Server hardware advice. Steven Mainor <steve@degga.net> - 2019-08-09 08:00 +0200
            Re: Server hardware advice. John Hasler <jhasler@newsguy.com> - 2019-08-09 15:40 +0200
              Re: Server hardware advice. deloptes <deloptes@gmail.com> - 2019-08-09 18:20 +0200
                Re: Server hardware advice. Reco <recoverym4n@enotuniq.net> - 2019-08-09 19:00 +0200
                Re: Server hardware advice. Celejar <celejar@gmail.com> - 2019-08-09 19:20 +0200
                Re: Server hardware advice. Reco <recoverym4n@enotuniq.net> - 2019-08-09 20:30 +0200
                OT "x times cheaper", was: Re: Server hardware advice. Richard Hector <richard@walnut.gen.nz> - 2019-08-10 10:00 +0200
                Re: OT "x times cheaper", was: Re: Server hardware advice. deloptes <deloptes@gmail.com> - 2019-08-10 11:20 +0200
                Re: OT "x times cheaper", was: Re: Server hardware advice. Richard Hector <richard@walnut.gen.nz> - 2019-08-10 11:30 +0200
                Re: OT "x times cheaper", was: Re: Server hardware advice. David Wright <deblis@lionunicorn.co.uk> - 2019-08-10 17:10 +0200
                Re: OT "x times cheaper", was: Re: Server hardware advice. Richard Hector <richard@walnut.gen.nz> - 2019-08-11 00:50 +0200
                Re: OT "x times cheaper", was: Re: Server hardware advice. mick crane <mick.crane@gmail.com> - 2019-08-11 09:50 +0200
                Re: OT "x times cheaper", was: Re: Server hardware advice. Curt <curty@free.fr> - 2019-08-11 12:00 +0200
                Re: Server hardware advice. John Hasler <jhasler@newsguy.com> - 2019-08-09 19:50 +0200
                Re: Server hardware advice. Steven Mainor <steve@degga.net> - 2019-08-10 04:00 +0200
    Re: Server hardware advice. Steven Mainor <steve@degga.net> - 2019-08-07 12:00 +0200
      Re: Server hardware advice. Reco <recoverym4n@enotuniq.net> - 2019-08-07 13:00 +0200
  Re: Server hardware advice. David Christensen <dpchrist@holgerdanske.com> - 2019-08-08 09:10 +0200
    Re: Server hardware advice. John Hasler <jhasler@newsguy.com> - 2019-08-08 15:20 +0200
    Re: Server hardware advice. Celejar <celejar@gmail.com> - 2019-08-08 15:50 +0200
      Re: Server hardware advice. Dan Ritter <dsr@randomstring.org> - 2019-08-08 16:30 +0200
        Re: Server hardware advice. Jonas Smedegaard <jonas@jones.dk> - 2019-08-08 17:00 +0200
          Re: Server hardware advice. Reco <recoverym4n@enotuniq.net> - 2019-08-08 17:30 +0200
            Re: Server hardware advice. Jonas Smedegaard <jonas@jones.dk> - 2019-08-08 18:20 +0200
              Re: Server hardware advice. Steven Mainor <steve@degga.net> - 2019-08-08 22:50 +0200
                Re: Server hardware advice. Dan Ritter <dsr@randomstring.org> - 2019-08-08 23:10 +0200
                Re: Server hardware advice. Michael Stone <mstone@debian.org> - 2019-08-08 23:20 +0200
        Re: Server hardware advice. David Christensen <dpchrist@holgerdanske.com> - 2019-08-09 00:10 +0200
  Re: Server hardware advice. Igor Cicimov <icicimov@gmail.com> - 2019-08-09 12:20 +0200

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