is there a limit to file size on a 32 bit HP-UX machine?

[Kaps_2]

Hi All,

Is there a limit to file size on a 32 Bit HP-UX system? What can be the max size of an individual file?

Thanks,
Kaps

[Pete Randall]

Kaps,

Check the last answer in this thread:

http://forums11.itrc.hp.com/service/forums/questionanswer.do?threadId=828156


Pete

[Kaps_2]

Hi Pete,

Please check my uname output and let me know what can be the max size of a single file.

# uname -a
HP-UX B.11.11 U 9000/800 1279464801 unlimited-user license

[Paul McCleary]

Hi,

Yes there is, you need to be considering the largefiles setting for your filesystem and the version of VxFS and the disk layout version.
e.g. JFS 3.3 Disk Layout 2 supports a maximum of 2GB.

Largefiles not enabled and it is a 2GB limit.

With it enabled (and assuming recent JFS and disk layout versions) I don't think it is limited to 4GB (or 3.75) as you might expect as there are extensions to allow 32-bit systems to handle large files, but I don't have details of these.

I think the current limit for a 64-bit system is 2TB with possibility of a 32TB filesystem.

Hope this helps,
Paul

[Pete Randall]

It's either 2GB or 2TB, depending on which version of JFS you have. I'm not quite sure how to determine the JFS version, though.


Pete

[Dennis Handly]

>Please check my uname output and let me know what can be the max size of a single file.
>HP-UX B.11.11 U 9000/800

Pete's link was pretty clear. You are suppose to know that B.11.11 == 11i.
What is the output for model?

[Steven Schweda]

> [...] as you might expect [...]

Pointer size and maximum file size (file
offset) are not intrinsically related. Many
32-bit-pointer environments offer file
systems (and OS infrastructure) which support
large (>2GB or >4GB) files.

[Kaps_2]

Hi Dennis,

The output for model is

# model
9000/800/rp3410

[Dennis Handly]

>9000/800/rp3410

This says that you have a PA-8900 and your OS is 64 bit!

So your questions are really:
1) what is the maximum file size.
2) And with a 32 bit application, how can I access these large files? (Steven's remark)

The answer to 2 is to read:
http://docs.hp.com/en/5964-5283/ch02s09.html
http://docs.hp.com/en/940/lgfiles4.pdf

[Bill Hassell]

> 9000/800/rp3410

This is not a 32bit processor so your kernel is actually a 64bit kernel. However, 32bit programs and applications can run on this kernel. That said, a 32bit program has the option of using system calls such as lseek64 rather than lseek in order to use large files.

So the question is about your application program *and* the filesystem where you are creating/using a largefile. Start with the filesystem:

fsadm /var
nolargefiles

This indicates that any file under the /var mountpoint can be no loarger than 2GB.

fsadm /usr
largefiles

and the above shows that large file may be created under /usr. Until your destination mountpoint allows largefiles, no program can create anything larger than 2GB.

The second part is the program itself. Is the program a 32 bit program? (hint: file myprogramname) Was it coded specifically to handle files larger than 2GB? Many very old programs use legacy interfaces such as lseek (rather than lseek64). These programs can never create or read a file larger than 2GB.

[Steven Schweda]

> [...] These programs can never create or
> read a file larger than 2GB.

Some can, if well written, and if compiled
with appropriate macros defined. lseek(),
for example, uses off_t, which may be either
"typedef long" (32-bit) or "typedef int64_t"
(64-bit), depending on

# if defined(_APP32_64BIT_OFF_T) || defined(_KERNEL)

(See "/usr/include/sys/types.h".)

Programs which are badly (or simply) written,
or which use more complex data structures
with file offsets hidden inside (Info-ZIP Zip
and UnZip, for example) will need more than a
re-build to get large-file support.