Re: floppy disk multitasking problems
Quoting Sasha Gutfraind (escape1984@rocketmail.com):
> I've a rather general technical question.
> Floppy drives have been around for who knows how much
> time. But even more, it seems that they originated
> not from multitasking OSs like UN*X and Linux, but
> from Macs and PCs running DOS.
> Correct me if I'm wrong, but it seems that whenever I
> mount a floppy, the whole Linux multitsking stops. It
> is as though the mounting of a floppy is an
> uninteruptable process. Maybe HDDs are relatively
> fast, but I never notice such problems when mounting
> them.
> What is the reason for the delay in the system when
> floppies are mounted? why it doesn't effect HDDs,
> they are also physical drives? Buffer problems?
I've tried to replicate your observation but have failed.
What exactly do you mean by "the whole Linux multitsking stops"?
How can you tell what has stopped.
I've tried it with floppies, but the best device seems to be a
jaz drive which can take an appreciable amount of time (say a
second or so) to mount, and is plainly audible.
If I run a process that's printing rapidly but steadily to an xterm
(so I can easily see any hiccup), mounting a disk has no effect.
If I mount a disk and then switch X between screens (using Alt-arrow
keys), then /mount/ is the process that pauses briefly, presumably
while X computes and paints the new screen. I can hear mount pausing.
BTW there is a reason why writing to a floppy and an IDE disk at the
same time might not be happening, but it's because of certain faulty
chipsets (CMD640 and RZ1000) and not because of linux. Though it's
not an OS issue, DOS is unaffected, IIUC, because it doesn't even
try to write simultaneously. The gory details are/used to be at
ftp://garbo.uwasa.fi/pc/diskutil/eidete19.zip
Cheers,
--
Email: d.wright@open.ac.uk Tel: +44 1908 653 739 Fax: +44 1908 655 151
Snail: David Wright, Earth Science Dept., Milton Keynes, England, MK7 6AA
Disclaimer: These addresses are only for reaching me, and do not signify
official stationery. Views expressed here are either my own or plagiarised.
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