Factors deciding the Maximum FS and file size

[manish77]

For any version of HP-UX OS, what are the factors that decide the maximum File Size and FileSystem Size?

On a 32 bit machine: Since file size is a 32 bit field: 2^32~ 4GB is the maximum possible value.
Can anyone guide me with additional fields that could account for Max FileSystem size and max file size in that Filesystem?

Thanks,
Manish

[Jaime Bolanos Rojas.]

Manish77,

Please check this doc as it will give you some answers,

http://docs.hp.com/en/5971-2383/5971-2383.pdf

Regards,

Jaime.

[Peter Godron]

Manish,
for largest SUPPORTED HFS / JFS sizes:
http://docs.hp.com/en/5971-2383/5971-2383.pdf

[manish77]

James/Peter,

Thanks a lot for the quick response.
The doc contains the values for Max file and FS size values for different FS on diffrent version of hpux.
I was actually looking for a formula or equation kind of thing to calculate the max file size and Max Filesystem size for a given Filesystem.

-Manish

[Peter Godron · Accepted solution]

Manish,
do you mean :
Can I create a single 12345 TB file on a 67890 TB disk under HP 11?

The deciding factors in that case will be:
1. process set limit on filesize you can create (ulimit)
2. size of the physical disk
3. size of the mountpoint you have created
4. size of addressable space (ie. 32/64 bit)

[James R. Ferguson]

Hi Manish:

If what you really want is not the filesystem sizes under various versions of JFS (VxFS), then the Software Recovery Handbook offers the maximum underlying LVM geometries ('max_pe') values:

http://www1.itrc.hp.com/service/iv/docDisplay.do?docId=prodITRC/DE_SW_UX_swrec_EN_01_E/LVM.pdf

Regards!

...JRF...

[inventsekar_1]

From man mkfs_hfs:
largefiles|nolargefiles
Controls the largefile featurebit for the file system. The
default is nolargefiles. This means the bit is not set, and
files created on the file system will be limited to less
than 2 gigabytes in size. If largefiles is specified, the
bit is set and the maximum size for files created on the
file system is not limited to 2 gigabytes (see mount_hfs(1M)
and fsadm_hfs(1M)).

also refer,
man mkfs_vxfs
man fsadm_hfs

[Bill Hassell]

The 32bit limitation does not come into play since files larger than 2Gb can be accessed using lseek64 even by a 32bit program. So tyhe maximum allowable file size and filesystem size depends on the version of HP-UX you are using. For instance, if you are running the obsolete version 10.20, you can create a 15 Gb logical volume and use newfs to create an empty directory on it. Then either create or restore any file that will fit in that directory.

[manish77]

Thanks a lot everyone for clarification. Thanks Peter for consolidationg the points.

I looked at the Whitepaper for largefile support that helped me out in further clarifications.

Thanks again.

-Manish