colinux-users

[coLinux-users] giving a uuid in config file / command line

[Andrew R. <and...@gm...>]

Hi all,

Is it possible to give a uuid on the config / command line in a similar way
that you can give an eth device a MAC address?

ex

hda3=\Device\Harddisk0\Partition3, 94749C99749C7FA2 # <-- specify uuid

where the line in fstab is

# /dev/sda3
UUID=94749C99749C7FA2 /media/sda3     ntfs    defaults,umask=007,gid=46 0

Because for some reason my ntfs partitions get a different uuid in colinux.
Actually, I would be interested to know if that would be a bug or not.

thanks
-Andrew

Re: [coLinux-users] giving a uuid in config file / command line

[Henry N. <Hen...@Ar...>]

Andrew Roth wrote:
> Hi all,
> 
> Is it possible to give a uuid on the config / command line in a similar
> way that you can give an eth device a MAC address?
> 
> ex
> 
> hda3=\Device\Harddisk0\Partition3, 94749C99749C7FA2 # <-- specify uuid
> 
> where the line in fstab is
> 
> # /dev/sda3
> UUID=94749C99749C7FA2 /media/sda3     ntfs    defaults,umask=007,gid=46 0
> 
> Because for some reason my ntfs partitions get a different uuid in
> colinux.  Actually, I would be interested to know if that would be a bug
> or not.

The UUID is reading from filesystem, are some bytes from filesystem
superblock and is named GUID of volume.

Big warning! Don't mount a ntfs partition, if it is online in Windows
(have a drive letter). You risk reading wrong datas.

You should use cofs for accessing this drive.

-- 
Henry N.

Re: [coLinux-users] giving a uuid in config file / command line

[Andrew R. <and...@gm...>]

It does have a drive letter in windows, but I haven't had any problems with
it.  I would use cofs, but if I can be blunt, I found it pretty useless
because I got "Fsync failed" when I tried to do anything useful.  For
example, I got that error when I tried to edit a file in vim, and also got
it when I tried to run /script/server in a ruby application, which runs a
light web server to test a ruby on rails application.  But I guess it's
useful for straight copies.

Ok then, can we give cofs a uuid?  That way I can use the same /etc/fstab
file which specifies the uuid now instead of a /dev/.. path.

-Andrew

On Fri, Mar 21, 2008 at 8:23 AM, Henry Nestler <Hen...@ar...> wrote:

> Andrew Roth wrote:
> > Hi all,
> >
> > Is it possible to give a uuid on the config / command line in a similar
> > way that you can give an eth device a MAC address?
> >
> > ex
> >
> > hda3=\Device\Harddisk0\Partition3, 94749C99749C7FA2 # <-- specify uuid
> >
> > where the line in fstab is
> >
> > # /dev/sda3
> > UUID=94749C99749C7FA2 /media/sda3     ntfs    defaults,umask=007,gid=46
> 0
> >
> > Because for some reason my ntfs partitions get a different uuid in
> > colinux.  Actually, I would be interested to know if that would be a bug
> > or not.
>
> The UUID is reading from filesystem, are some bytes from filesystem
> superblock and is named GUID of volume.
>
> Big warning! Don't mount a ntfs partition, if it is online in Windows
> (have a drive letter). You risk reading wrong datas.
>
> You should use cofs for accessing this drive.
>
> --
> Henry N.
>

Re: [coLinux-users] giving a uuid in config file / command line

[Henry N. <Hen...@Ar...>]

Hello Andrew,

if you have a drive letter under Windows, then Windows has opened the
drive and not all buffer must be in the dist. Linux with cobd opens the
same drive but not known about non written file buffers from windows
side. So you can got some other datas from file in inside coLinx as on
the Windows side. If you would create directories on Windows side,
coLinux would not see it, or some times later, after windows was writte
the buffers to disk.

The fsync on cofs was fixed. Please use a newer version from
http://www.colinux.org/snapshots/

Cofs has no UUID, cofs is not a disk it is a filesystem (same as nfs,
smbfs).

You means to deal with dualboot?
I have hack for SuSE 9.0. There I have changed the exclude list for
"mount -a" to have cofs under coLinux and nfts under native boot. On
coLinux I mount the cofs to the same place with the '--bind' option.

This are the lines in /etc/fstab:
/dev/hda2  /media/WinXP  ntfs
ro,auto,uid=hn,gid=users,user,fmask=0113,dmask=0002 0 0
cofs0:/  /media/cofs0  cofs
auto,user,noexec,uid=hn,gid=users,fmask=0664,dmask=0775 0 0


Changes and adds on /etc/init.d/boot.localfs:

... near the top I have ...
# Switch between coLinux and real linux
if uname -r | grep -qe "-co-"
then
        COLINUX=true

        echo " FSCK skip (colinux)"
        export fastboot=true

        # Mounts for coLinux
        COLINUX_EXCLUSE="nontfs,novfat"
else
        COLINUX=false

        # Mounts for native Linux
        COLINUX_EXCLUSE="nocofs"
fi

... some lines later ...

#mount -av -t nonfs,noproc,nodevpts,nosmbfs
mount -av -t nonfs,noproc,nodevpts,nosmbfs,$COLINUX_EXCLUSE

# Remount from cofs into original place for ntfs
if $COLINUX ; then
        mount --bind /media/cofs0       /media/WinXP
fi



Andrew Roth wrote:
> It does have a drive letter in windows, but I haven't had any problems
> with it.  I would use cofs, but if I can be blunt, I found it pretty
> useless because I got "Fsync failed" when I tried to do anything
> useful.  For example, I got that error when I tried to edit a file in
> vim, and also got it when I tried to run /script/server in a ruby
> application, which runs a light web server to test a ruby on rails
> application.  But I guess it's useful for straight copies.
> 
> Ok then, can we give cofs a uuid?  That way I can use the same
> /etc/fstab file which specifies the uuid now instead of a /dev/.. path.
> 
> -Andrew
> 
> On Fri, Mar 21, 2008 at 8:23 AM, Henry Nestler <Hen...@ar...
> <mailto:Hen...@ar...>> wrote:
> 
>     Andrew Roth wrote:
>     > Hi all,
>     >
>     > Is it possible to give a uuid on the config / command line in a
>     similar
>     > way that you can give an eth device a MAC address?
>     >
>     > ex
>     >
>     > hda3=\Device\Harddisk0\Partition3, 94749C99749C7FA2 # <-- specify uuid
>     >
>     > where the line in fstab is
>     >
>     > # /dev/sda3
>     > UUID=94749C99749C7FA2 /media/sda3     ntfs  
>      defaults,umask=007,gid=46 0
>     >
>     > Because for some reason my ntfs partitions get a different uuid in
>     > colinux.  Actually, I would be interested to know if that would be
>     a bug
>     > or not.
> 
>     The UUID is reading from filesystem, are some bytes from filesystem
>     superblock and is named GUID of volume.
> 
>     Big warning! Don't mount a ntfs partition, if it is online in Windows
>     (have a drive letter). You risk reading wrong datas.
> 
>     You should use cofs for accessing this drive.
> 
>     --
>     Henry N.
> 
> 

-- 
Henry N.

Re: [coLinux-users] giving a uuid in config file / command line

[<Use...@zo...>]

and...@gm...(Andrew Roth)  21.03.08 11:29


>It does have a drive letter in windows, but I haven't had any problems
>with it.  

...yet.

Lucky you!

Windows is noting the time of last access, so you can't
avoid Windows writing to the directory structure, for example if
the virusscanner is working. Linux is noting that access too.

What will happen if Colinux and Windows
are writing to the same directory structure part?

So "only reading" would not help, as the time stamps do still "write".

Mount it "read only" to avoid linux updating access time or turn time
stamping off.

BTW:
Does anybody know how to mount a partition "read only" under Windows?



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