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Re: Question about umount and sync

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On a sunny day (Thu, 21 Aug 2014 13:22:29 +0000 (UTC)) it happened Joe
Beanfish <joebeanfish@nospam.duh> wrote in <lt4rqk$k6v$1@dont-email.me>:

>Linux has caching on block devices. Make sure you use a raw device.
>See http://www.tldp.org/HOWTO/SCSI-2.4-HOWTO/rawdev.html

Interesting, did not know about 'raw',
but used dd with the correct sector size.

Maybe in some cases 'raw' is faster.

What I have done a lot of times is just tar a directory,
and then
 growisofs [options] -Z /dev/dvd=big_tar.gz

dvd can be dvd or cd or bluray or some other media
This used for backups.

Then when you want to get everything back:
tar -zxvf /dev/dvd

Or write a whole movie to a dvd-r.
cat /dev/dvd | mplayer - for the cat people.
dd if=/dev/dvd bs=10000000 skip=1000 | mplayer - to start halfway  in the movie.
Saves time authoring disks.
Actually I do that from main PC to laptop to watch movies via netcat too.
works great (recording HD movies on the main PC via USB sat receiver) and watching
in other room on laptop..
scripted of course.

About not using filesystems, I recentley designed a GPS based litte radiation counter, GPS logger,
that writes to SDcard,
and a simple C program to display the data (and show the location in google maps).
read_gmp_card-0.3.c 
See:
 http://panteltje.com/panteltje/pic/gm_pic2/
Who needs filesystems... 

Maybe I can use 'raw' for some fast video stuff.
one of the advantages of writing directly is that all sectors are sequential...
reducing seek times, at least for old media it was, modern media controllers do whatever they like
like bad sector management, write limiting, etc (cards).

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Question about umount and sync Jan Panteltje <pNaonStpealmtje@yahoo.com> - 2012-06-29 16:44 +0000
  Re: Question about umount and sync Joe Beanfish <joebeanfish@nospam.duh> - 2012-06-29 15:47 -0400
    Re: Question about umount and sync Jan Panteltje <pNaonStpealmtje@yahoo.com> - 2012-06-30 06:20 +0000
    Re: Question about umount and sync Richard Kettlewell <rjk@greenend.org.uk> - 2012-06-30 13:16 +0100
      Re: Question about umount and sync Joe Beanfish <joebeanfish@nospam.duh> - 2012-07-02 10:07 -0400
    Re: Question about umount and sync ameliusje@gmail.com - 2014-08-18 12:58 -0700
      Re: Question about umount and sync Joe Beanfish <joebeanfish@nospam.duh> - 2014-08-19 13:29 +0000
        Re: Question about umount and sync Jan Panteltje <pNaonStpealmtje@yahoo.com> - 2014-08-19 14:09 +0000
          Re: Question about umount and sync Joe Beanfish <joebeanfish@nospam.duh> - 2014-08-21 13:22 +0000
            Re: Question about umount and sync Jan Panteltje <pNaonStpealmtje@yahoo.com> - 2014-08-21 14:15 +0000

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