Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]


Groups > linux.debian.user > #237486

Re: RAID-1 and disk I/O

From Andy Smith <andy@strugglers.net>
Newsgroups linux.debian.user
Subject Re: RAID-1 and disk I/O
Date 2021-07-17 17:00 +0200
Message-ID <CBTXj-1FR-1@gated-at.bofh.it> (permalink)
References <CBRVv-rW-1@gated-at.bofh.it>
Organization linux.* mail to news gateway

Show all headers | View raw


Hi Urs,

Your plan to change the SATA cable seems wise - your various error
rates are higher than I have normally seen.

Also worth bearing in mind that Linux MD RAID 1 will satisfy all
read IO for a given operation from one device in the mirror. If
you have processes that do occasional big reads then by chance those
can end up being served by the same device leading to a big
disparity in per-device LBAs read.

You can do RAID-10 (even on 2 or 3 devices) which will stripe data
at the chunk size resulting in even a single read operation being
striped across multiple devices, though overall this may not be more
performant than RAID-1, especially if your devices were
non-rotational. You would have to measure.

I don't know about the write overhead you are seeing.

Cheers,
Andy

-- 
https://bitfolk.com/ -- No-nonsense VPS hosting

Back to linux.debian.user | Previous | NextPrevious in thread | Next in thread | Find similar | Unroll thread


Thread

RAID-1 and disk I/O Urs Thuermann <urs@isnogud.escape.de> - 2021-07-17 14:50 +0200
  Re: RAID-1 and disk I/O Nicholas Geovanis <nickgeovanis@gmail.com> - 2021-07-17 16:40 +0200
  Re: RAID-1 and disk I/O Bob Weber <bobrweber@gmail.com> - 2021-07-17 16:50 +0200
  Re: RAID-1 and disk I/O Andy Smith <andy@strugglers.net> - 2021-07-17 17:00 +0200
  Re: RAID-1 and disk I/O David Christensen <dpchrist@holgerdanske.com> - 2021-07-17 23:10 +0200
    Re: RAID-1 and disk I/O David <bouncingcats@gmail.com> - 2021-07-18 03:40 +0200
      Re: RAID-1 and disk I/O David Christensen <dpchrist@holgerdanske.com> - 2021-07-18 09:10 +0200
      Re: RAID-1 and disk I/O rhkramer@gmail.com - 2021-07-18 13:10 +0200
        Re: RAID-1 and disk I/O David <bouncingcats@gmail.com> - 2021-07-18 15:40 +0200
          Re: RAID-1 and disk I/O rhkramer@gmail.com - 2021-07-19 01:40 +0200
    Re: RAID-1 and disk I/O Reco <recoverym4n@enotuniq.net> - 2021-07-18 11:20 +0200
      Re: RAID-1 and disk I/O David Christensen <dpchrist@holgerdanske.com> - 2021-07-18 23:00 +0200
    Re: RAID-1 and disk I/O Urs Thuermann <urs@isnogud.escape.de> - 2021-07-18 23:40 +0200
      Re: RAID-1 and disk I/O David Christensen <dpchrist@holgerdanske.com> - 2021-07-19 00:50 +0200

csiph-web