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Re: Measuring (or calculating) how many bytes are actually written to disk when I repeatedly save a file


On Sun, Apr 07, 2019 at 10:10:58PM +0200, Carles Pina i Estany wrote:
> Hi,
> On Apr/06/2019, rhkramer@xxxxxxxxx wrote:
> > Can anyone confirm that, and, if so, suggest any way of measuring how much is 
> > written to a given file in a given time period (e.g., per day)?
> > 
> > I guess at a very deep level (I mean like at the level of the disk firmware or 
> > driver level), this may differ between an SSD and an HDD -- if you have any 
> > insight into that, I'd appreciate that.
> In my SSDs I have:
> /sys/fs/ext4/dm-0/lifetime_write_kbytes
> I'm not sure if this is specific for SSD?

No, it's not. It's filesystem-specific though.
Meaning - you have to use ext4 to see this attribute, but the device
where the ext4 filesystem resides does not matter.