Unexpectedly high writes



  • Some data for this topic.

    64 gig KINGSTON SMS200S360G

    This drive is not dramless, and is MLC. Clearly over spec'd in size but that extends useable cells. I did 10% manual over provisioning.

    I have ram disks enabled, so logs, rrd etc goto ramdisk. With 1 hour persistent backups.

    The write stats are much higher then I would expect, but even with the high amount of data written the drive has not even moved down 1% on its predicted life.

    230 Life_Curve_Status       0x0013   100   100   000    Pre-fail  Always       -       100
    231 SSD_Life_Left           0x0000   100   100   011    Old_age   Offline      -       0
    233 SandForce_Internal      0x0032   000   000   000    Old_age   Always       -       1428
    234 SandForce_Internal      0x0032   000   000   000    Old_age   Always       -       817
    241 Lifetime_Writes_GiB     0x0032   000   000   000    Old_age   Always       -       817
    242 Lifetime_Reads_GiB      0x0032   000   000   000    Old_age   Always       -       27
    

    So basically 1.4tb written uncompressed, this is about 2 years usage. The sandforce controller has reduced it to 817gb of writes.

    Predicted life is still sub 1% used.

    I honestly dont know what has been written to cause those high write stats but regardless, the SSD has plenty of life left after 2 years of usage.

    Care should be taken tho when buying SSD's in this price bracket, kingston e.g. are kinda bait and switching, a lot of their newer models are TLC replacing MLC models, some I think might even be dramless, all their competitors are unknown chinese brands, as samsung and co dont want to compete in this price bracket. You can find their better drives typically second hand, but I would rather buy a second hand MLC with dram drive than a dramless TLC drive. But thought I would provide these figures anyway to help others.

    Finally there is 18 power cuts logged in the SMART stats which is probably right as the unit has suffered a fair bit from power cuts and is now on a UPS to prevent even more.


  • Netgate Administrator

    Split this off as that other topic was both waaay old and has misinformation in it.

    That does seem like a much higher write value that I would expect. Do you remember which version you originally installed on that drive? Have you reinstalled any other version since?

    Can we see the output of mount -p ?

    Steve



  • @chrcoluk Is the drive mounted noatime? I was able to reduce a lot of writes with that option.


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