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

Groups > linux.debian.user > #205326

Re: Swap space choice on a SSD <- Current best practice on?

Show all headers | View raw

On 2/13/19 1:23 PM, Dan Ritter wrote:
> David Christensen wrote:
>> On 2/13/19 6:11 AM, Dan Ritter wrote:
>>> If you want maximum SSD longevity, increase the amount of space that
>>> the SSD can use for remapping by never writing to some amount of
>>> space. Easiest is to not fill the disk with partitions -- leave 5-10%
>>> empty.
>>
>> AFAIK over-provisioning has no effect on longevity -- longevity is
>> proportional to total number of cells times rated erase/ write cycles
>> per cell divided by write throughput.
>>
>>
>> But, over-provisioning can improve write performance:
>>
>> https://en.wikipedia.org/wiki/Write_amplification#Over-provisioning
> 
> Effective longevity depends on the number of times a block is
> erased and written to. You can reduce that over the course of an
> SSD's lifetime by limiting the space you think you have
> available.
> 
> From the article you cited:
> 
> "Over-provisioning often takes away from user capacity, either
> temporarily or permanently, but it gives back reduced write
> amplification, increased endurance, and increased performance."
> 
> Increased endurance is increased longevity.

SSD manufacturers taking away part of the capacity and then telling us 
the drive has increased endurance measured against the reduced size is 
marketing speak.  (Similar rant for kB, MB, GB, etc..)


I use the term "over-provisioning" in the context of this mailing list 
-- e.g. what we can do as Debian users (and system administrators):

"Furthermore, if any SSD is set up with an overall partitioning layout 
smaller than 100% of the available space, that unpartitioned space will 
be automatically used by the SSD as over-provisioning as well."


Whether you partition the first 90% of an SSD and write X blocks at 
random intervals over some time period T, or partition 100% and do the 
same, the number of Program/ Erase (P/E) cycles will be the same.  (But 
the timing/ performance of clustered writes may differ.)  When X gets 
large enough, the drive will eventually fail.  I would call that X the 
endurance of the drive.  (Intel converts it to a MTBF of 1,200,000 hours 
for my Series 520 SSD's.)


So, over-provisioning *by Debian users* has no effect on longevity.


David

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

Thread

WiFi without Network Manager Kenneth Parker <sea7kenp@gmail.com> - 2019-02-12 15:20 +0100
  Re: WiFi without Network Manager <tomas@tuxteam.de> - 2019-02-12 15:40 +0100
    Re: WiFi without Network Manager Kenneth Parker <sea7kenp@gmail.com> - 2019-02-12 15:50 +0100
      Re: WiFi without Network Manager <tomas@tuxteam.de> - 2019-02-12 16:00 +0100
        Re: WiFi without Network Manager Kenneth Parker <sea7kenp@gmail.com> - 2019-02-12 19:00 +0100
          Re: WiFi without Network Manager Eduardo M KALINOWSKI <eduardo@kalinowski.com.br> - 2019-02-12 19:50 +0100
            Re: WiFi without Network Manager Kenneth Parker <sea7kenp@gmail.com> - 2019-02-12 20:10 +0100
    Re: WiFi without Network Manager Kenneth Parker <sea7kenp@gmail.com> - 2019-02-15 00:30 +0100
      Re: WiFi without Network Manager mett <mett@pmars.jp> - 2019-02-15 05:00 +0100
        Re: WiFi without Network Manager Kenneth Parker <sea7kenp@gmail.com> - 2019-02-15 06:00 +0100
          Re: WiFi without Network Manager didier gaumet <didier.gaumet@gmail.com> - 2019-02-15 09:10 +0100
  Re: WiFi without Network Manager ghe <ghe@slsware.net> - 2019-02-12 15:50 +0100
    Glenn -> Re: WiFi without Network Manager deb <deb@rangingthoughts.org> - 2019-02-12 17:20 +0100
      Re: WiFi without Network Manager ghe <ghe@slsware.net> - 2019-02-12 21:10 +0100
        Re: WiFi without Network Manager deb <deb@rangingthoughts.org> - 2019-02-13 14:40 +0100
          Re: WiFi without Network Manager rhkramer@gmail.com - 2019-02-13 14:50 +0100
            Re: WiFi without Network Manager John Hasler <jhasler@newsguy.com> - 2019-02-13 15:20 +0100
              Re: WiFi without Network Manager Ric Moore <wayward4now@gmail.com> - 2019-02-13 17:40 +0100
          Re: WiFi without Network Manager mick crane <mick.crane@gmail.com> - 2019-02-13 15:00 +0100
        Swap space choice on a SSD <- Current best practice on? deb <deb@rangingthoughts.org> - 2019-02-13 14:50 +0100
          Re: Swap space choice on a SSD <- Current best practice on? Michael Stone <mstone@debian.org> - 2019-02-13 14:50 +0100
            Re: Swap space choice on a SSD <- Current best practice on? deb <deb@rangingthoughts.org> - 2019-02-13 15:00 +0100
              Re: Swap space choice on a SSD <- Current best practice on? Dan Ritter <dsr@randomstring.org> - 2019-02-13 15:20 +0100
                Thanks Dan. Re: Swap space choice on a SSD <- Current best practice  on? deb <deb@rangingthoughts.org> - 2019-02-13 15:40 +0100
          Re: Swap space choice on a SSD <- Current best practice on? David Christensen <dpchrist@holgerdanske.com> - 2019-02-13 22:20 +0100
            Re: Swap space choice on a SSD <- Current best practice on? Dan Ritter <dsr@randomstring.org> - 2019-02-13 22:30 +0100
              Re: Swap space choice on a SSD <- Current best practice on? Andy Smith <andy@strugglers.net> - 2019-02-13 22:50 +0100
              Re: Swap space choice on a SSD <- Current best practice on? David Christensen <dpchrist@holgerdanske.com> - 2019-02-14 05:20 +0100
            Re: Swap space choice on a SSD <- Current best practice on? Andy Smith <andy@strugglers.net> - 2019-02-13 22:30 +0100
              Re: Swap space choice on a SSD <- Current best practice on? David Christensen <dpchrist@holgerdanske.com> - 2019-02-14 05:30 +0100
            Re: Swap space choice on a SSD <- Current best practice on? Michael Stone <mstone@debian.org> - 2019-02-13 22:30 +0100

csiph-web