Re: Capacitors, etc., in hard drives and SSD for DBMS machines... - Mailing list pgsql-performance

From vincent
Subject Re: Capacitors, etc., in hard drives and SSD for DBMS machines...
Date
Msg-id 25c2789d-8cfe-bd9d-3d48-7c36f10a6647@xs4all.nl
Whole thread Raw
In response to Capacitors, etc., in hard drives and SSD for DBMS machines...  (Jean-David Beyer <jeandavid8@verizon.net>)
Responses Re: Capacitors, etc., in hard drives and SSD for DBMS machines...  (Jean-David Beyer <jeandavid8@verizon.net>)
List pgsql-performance

Op 7/8/2016 om 12:23 PM schreef Jean-David Beyer:
> Why all this concern about how long a disk (or SSD) drive can stay up
> after a power failure?
>
> It seems to me that anyone interested in maintaining an important
> database would have suitable backup power on their entire systems,
> including the disk drives, so they could coast over any power loss.
>
As others have mentioned; *any* link in the power line can fail, from
the building's power
to the plug literaly falling out of the harddisk itself. Using multiple
power sources,
UPS, BBU etc reduce the risk, but the internal capacitors of an SSD are
the only thing
that will *always* provide power to the disk, no matter what caused the
power to fail.

It's like having a small UPS in the disk itself, with near-zero chance
of failure.


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