I'm considering and update from HDD to SSD. But since Flash cells can only sustain limited writes. I want to know how much data my computer write during normal operation. So I can determine how long lifetime I can expect from the SSD.

Is it possible to get (rough) numbers somehow?


3 Answers 3


The first idea I found is the vmstat -d command.

It tells you the number of sectors written since booting.

fdisk -l will tell you the sector size.

By multiplying the two you can get the number of bytes touched.

It seems my computer does roughly 1 gigabytes worth of writing in two hours. By doing a quick calculation a 128G SSD with 3000 write cycles would last 90 years... Nothing to worry about.


Look at this page http://linuxpoison.blogspot.com.au/2009/02/how-to-measure-and-read-disk-activity.html

# cat /sys/block/sda/stat

11836508  1974427 276764974 242202738 13703385 18793696 597760590 2010426698      135 76333414 2253542452

Field 3 -- # of sectors read

Field 7 -- # of sectors written


Use iotop command

You can also use -a option to get total bytes write and read per process.

iotop -a


  • This should be iotop -a (for --accumulated, -P means something else)
    – oseiskar
    Jun 11, 2015 at 11:14

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