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




On Monday 08 April 2019 10:56:33 rhkramer@xxxxxxxxx wrote:

> On Monday, April 08, 2019 10:18:28 AM Curt wrote:
> > On 2019-04-08, rhkramer@xxxxxxxxx <rhkramer@xxxxxxxxx> wrote:
> > > And someone would (or should) ask what does "frequently" mean, and
> > > that is what I am trying to quantify.
> >
> > Sure. But below a certain level of granularity it becomes an
> > exercise for which the benefits remain to be established.  Large
> > files and frequent writes to disk are probably not ideal for an SSD.
> > You can read that anywhere. What else can anyone say?
>
> I've seen that implied, but not explicitly stated, nor with
> "quantification" (i.e., supporting evidence).
>
> > What are you trying to do?
> > Measure the daily byte-count of your writes and compare that to some
> > hypothetical standard or threshold above which it would be suggested
> > to employ an HDD rather than a SSD?
>
> As mentioned in another post, I am starting to fear for the
> reilability of an HDD (DOAs, early failures, unwilingness of the
> vendor / manufacturer to provide a warranty), and, therefore, I am
> trying to determine if an SSD could be a better choice.
>
> (Someday, I expect it will be -- is that day here?)

I don't think so, so where I do use them (the speed is nice!!!), I use 
them to maybe 20% of capacity so the drive has plenty of room to 
reassign a questionable spot. So as rust fails, I'm installing 40 to 60 
GB SSD's in my machine tools as the OS and files don't exceed around 5Gb 
even after years of carving metal.  And I have been doing so for over a 
year with zero problems.

OTOH, I have a now ancient seacrate 1Tb with 80,000+ spinning hours on 
it, had 25 reallocated sectors when I updated the firmware in it, 
gaining 30 mb/second in speeds both ways when it was about a month old. 
Its had its total contents rewritten at least 500 times as its been a 
virtual tape library for amanda since it was bought.  But when it hit 
90% full, I figured it was time for a new 2Tb. Currently saving the 
virtual tapes of a 5 machine network every night.  Its a good sata-II 
drive yet, still after all that time is reporting the same 25 
re-allocated sectors, and altho its out of a job, its still spinning 
because if shut down for several days, it will probably be hard to start 
because of stiction.

I have a pair of 1Gb seagates attached to a legacy computer in the 
basement, that probably have in excess of 200,000 hours on them. If shut 
down for 2 weeks, will need a gentle sideways tap with a rubber hammer 
on a front corner to start them, but neither has dropped a single bit 
since I took them out of a dying amiga nearly 15 years ago.
Spinning rust can be very dependable.

Cheers, Gene Heskett
-- 
"There are four boxes to be used in defense of liberty:
 soap, ballot, jury, and ammo. Please use in that order."
-Ed Howdershelt (Author)
Genes Web page <http://geneslinuxbox.net:6309/gene>