Re: SSD + RAID

Greg Smith wrote:
> Ron Mayer wrote:
> > Bruce Momjian wrote:
> >
> >> Agreed, thought I thought the problem was that SSDs lie about their
> >> cache flush like SATA drives do, or is there something I am missing?
> >>
> >
> > There's exactly one case I can find[1] where this century's IDE
> > drives lied more than any other drive with a cache:
>
> Ron is correct that the problem of mainstream SATA drives accepting the
> cache flush command but not actually doing anything with it is long gone
> at this point.  If you have a regular SATA drive, it almost certainly
> supports proper cache flushing.  And if your whole software/storage
> stacks understands all that, you should not end up with corrupted data
> just because there's a volative write cache in there.

OK, but I have a few questions.  Is a write to the drive and a cache
flush command the same?  Which file systems implement both?  I thought a
write to the drive was always assumed to flush it to the platters,
assuming the drive's cache is set to write-through.

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  Bruce Momjian  <bruce@momjian.us>        http://momjian.us
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