[comp.sys.att] floppy-sync-buffers

clint@wheeler (Clinton Case) (06/07/90)

How do you asure that floppy disks are synchronized with their
buffers (i.e. that the buffers get flushed) before removing the
disks?

I tried the following
	mount /dev/fp021 /mnta
	cp file /mnta
	umount /dev/fp021

and


	mount /dev/fp021 /mnta
	cp file /mnta
	sync
	umount /dev/fp021

and


	mount /dev/fp021 /mnta
	cp file /mnta
	dismount -f

AND ALL OF THESE PRODUCED AN INCOMPLETE COPY of file on /mnta !

.... While on the topic can someone provide a brief synopsis of
all the block and character special files in /dev ? Like what is
the difference between /dev/fp021 and rfp021 etc.  I can't seem
to find this information anywhere. Is there any special
significance to the name /mnta?

Any recommendations on good third party books on SYS V or ksh?

Many thanks in advance.
clint@unssun.nevada.edu
or
clint@wheeler.wrc.unr.edu

brad@slammer.UUCP (Brad Isley) (06/15/90)

In article <4074@tahoe.unr.edu> clint@wheeler (Clinton Case) writes:
>How do you asure that floppy disks are synchronized with their
>buffers (i.e. that the buffers get flushed) before removing the
>disks?

[various problems with floppies deleted...]

dismount -f takes care of this for you, however...

I have found that, sometimes, I can never successfully write to ANY floppy.
Sometimes I have to reformat and re-mkfs to get it to work.  Sometimes I have
to reboot my machine before it will work.

I archive several newsgroups to 3.5" floppies and ALWAYS do the following...

cp xxx /mnt
dismount -f
fsck /dev/rfp021

When I'm having problems the fsck will ALWAYS report:

Partially allocated inode:33
Clear?

Then it'll say

Partially allocated inode:34
Clear?

If I do not run fsck the symptoms are the same as you report.  Partial files.
The only solution I have found is to reboot. :-(  I'm running 3.51m.

fp021 is the block device.  Must read/write an entire block.
rfp021 is the raw device.  Can read/write across block boundaries.
-- 
brad@slammer.UUCP   (Brad Isley)