Simon Matter wrote:
...
> Jim,
>
> It's obvious that lifetime is reduced with write caching off. Just
> listen to the drive and compare between w/cache on / off. What helps
> here is that Linux uses memory for caching effectively.
>
> Some weeks ago I brought an issue to this list. I got zero filled files
> after _clean_ reboots and I thought it was the write cache of the IDE
> drives not flushing correctly. In fact I got bitten by the 'remount
> readonly bug' and it had nothing to do with the write chache being
> turned on.
I think I missed some of the "remount readonly" discussion. Can someone
summarize what the problem is and the correct way we should be doing a
controlled shutdown/reboot with XFS?
...
>
> Cache flushing does only work if the drive honours the flushing request
> correctly. What I recommend is trying to use drives which:
> - really flush cache when requested to do so.
> - flush cache on power failure.
The drive we are currently using does its best. It has a "power
failure" mode where the cache is flushed. I believe they re-order
requests to get as much data on the platter as possible in this mode.
We're trying to determine how how much time they have after the power is
cut.
Jim Buzbee,
Echostar Technologies
>
> The latter is quite important because comsumers will just pull power to
> turn it off. I don't know whether this feature is available with IDE
> drives but I think it should be possible.
>
> -Simon
>
> >
> > This has to be a common problem. Does anyone have any strategies or
> > words of wisdom?
> >
> > Jim Buzbee,
> > Echostar Technologies
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