large file support?

large file support?

[Steven Scholz]

Hi there,

how could I find out if the kernel and the glibc I am using will
correctly supprot large files (>2GB)?

Thanks,

Steven


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Re: large file support?

[Wolfgang Denk]

In message <3F28EFD6.3070803@imc-berlin.de> you wrote:
>
> how could I find out if the kernel and the glibc I am using will
> correctly supprot large files (>2GB)?

	char buf[4096];
	for (;;)
		write (fd, buf, sizeof(buf));

:-)


Best regards,

Wolfgang Denk

--
Software Engineering:  Embedded and Realtime Systems,  Embedded Linux
Phone: (+49)-8142-4596-87  Fax: (+49)-8142-4596-88  Email: wd@denx.de
Perl already has an IDE.  It's called Unix.
                      -- Tom Christiansen in 375bd509@cs.colorado.edu

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Re: large file support?

[Steven Scholz]

Wolfgang Denk wrote:

> In message <3F28EFD6.3070803@imc-berlin.de> you wrote:
>
>>how could I find out if the kernel and the glibc I am using will
>>correctly supprot large files (>2GB)?
>
>
> 	char buf[4096];
> 	for (;;)
> 		write (fd, buf, sizeof(buf));
>

:o)

But what will happen if I (or my application) have no large file
support, i.e. is the failure deterministic? And will it be obvious?
Just by do "ls -l"????

:-)

Thanks anyway!

Steven


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Re: large file support?

[Steven Scholz]

I wrote:

> how could I find out if the kernel and the glibc I am using will
> correctly supprot large files (>2GB)?

I reckon my app does not support large files. Since after writing 2GB
to a file

~ # ls -lh /mnt/intern/HDD_STRESS/2003-07-31\ 12-27-34\ \(1\)/
-rw-r--r--    1 root     root         1.0G Jul 31 13:57 K001_G0.raw
-rw-r--r--    1 root     root         1.0G Jul 31 13:57 K002_G0.raw
-rw-r--r--    1 root     root         2.0G Jul 31 13:57 V001_G0.raw
~

it claims "disk full" although

~ # df -h
Filesystem                Size      Used Available Use% Mounted on
/dev/mtdblock0            6.9M      5.1M      1.8M  74% /
/dev/shm                  7.1M     24.0k      7.1M   0% /var
/dev/hda1                 9.2G      4.0G      4.7G  46% /mnt/intern

Thanks,

Steven


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Re: large file support?

[Wolfgang Denk]

In message <3F290506.3060304@imc-berlin.de> you wrote:
>
> I reckon my app does not support large files. Since after writing 2GB
> to a file

Did  you  build  it  with  the  required  options,   like   #defining
_FILE_OFFSET_BITS as 64 ?


Best regards,

Wolfgang Denk

--
Software Engineering:  Embedded and Realtime Systems,  Embedded Linux
Phone: (+49)-8142-4596-87  Fax: (+49)-8142-4596-88  Email: wd@denx.de
You are only young once, but you can stay immature indefinitely.

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Re: large file support?

[Steven Scholz]

Wolfgang Denk wrote:

> In message <3F290506.3060304@imc-berlin.de> you wrote:
>
>>I reckon my app does not support large files. Since after writing 2GB
>>to a file
>
>
> Did  you  build  it  with  the  required  options,   like   #defining
> _FILE_OFFSET_BITS as 64 ?

Nope!
But good point! :o)
And I just got these lines:

Fillod Stephane wrote:
 > Recent kernel and glibc are fine.
 >
 > Pass O_LARGEFILE to the second open() arg, and compile
 > with "-D_LARGEFILE64_SOURCE -D_FILE_OFFSET_BITS=64" should do it.

and rebuilt my application. But the test (with my app) will take a
while...

Thanks!

Steven


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Re: large file support?

[Jerry Van Baren]

dd if=/dev/zero of=majorbigfile bs=1M count=2049

get a beer and wait ;-)

gvb


At 01:37 PM 7/31/2003 -0400, wd@denx.de wrote:

>In message <3F28EFD6.3070803@imc-berlin.de> you wrote:
> >
> > how could I find out if the kernel and the glibc I am using will
> > correctly supprot large files (>2GB)?
>
>         char buf[4096];
>         for (;;)
>                 write (fd, buf, sizeof(buf));
>
>:-)
>
>
>Best regards,
>
>Wolfgang Denk
>
>--
>Software Engineering:  Embedded and Realtime Systems,  Embedded Linux
>Phone: (+49)-8142-4596-87  Fax: (+49)-8142-4596-88  Email: wd@denx.de
>Perl already has an IDE.  It's called Unix.
>                       -- Tom Christiansen in 375bd509@cs.colorado.edu
>


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Re: large file support?

[Steven Scholz]

I wrote:

> And I just got these lines:
>
> Fillod Stephane wrote:
>  > Recent kernel and glibc are fine.
>  >
>  > Pass O_LARGEFILE to the second open() arg, and compile
>  > with "-D_LARGEFILE64_SOURCE -D_FILE_OFFSET_BITS=64" should do it.
>
> and rebuilt my application. But the test (with my app) will take a
> while...

Now I the app is still running although the file is > 2GB. I get

~ # ls -l /mnt/intern/HDD_STRESS/2003-07-31\ 1*
/mnt/intern/HDD_STRESS/2003-07-31 14-54-57 (1):
ls: /mnt/intern/HDD_STRESS/2003-07-31 14-54-57 (1)/V001_G0.raw: Value
too large for defined data type
-rw-r--r--    1 root     root    1080356864 Jul 31 16:25 K001_G0.raw
-rw-r--r--    1 root     root    1080356864 Jul 31 16:25 K002_G0.raw

I guess I have to rebuild busybox with LFS as well...

Thanks to you all!

Steven


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