OpenVMS V7.3-2 Disk File Optimizer Utility (DFO or DFG)

[Shaun Lim]

Can anyone enlighten me on my following questions?

1) Is there any limitation to BIG file size (>5GB) when using DFO?

2) If the available free block in the disk is less than the BIG file size, will defragmentation works?

Thank you very much.

[labadie_1 · Accepted solution]

Hello

1)
I have looked at the SPD
http://docs.hp.com/en/12795/SPDDFOv29.pdf?jumpid=reg_R1002_USEN

and you just need (for Vax, Alpha or Itanium) 20000 to 30000 free blocks, that is all.

2) yes, it will work.

[Wim Van den Wyngaert]

1) I would expect the maximum of VMS (4 Gblocks ?)

2) it will fail. It tries to allocate the file in 1 extent. If that space is not present, it will fail. DFU /BEST may however work.

Wim

[Wim Van den Wyngaert]

1) make that 2 Gblocks. And according to Jon only half of that can be contiguous (so 2 pointers for the biggest file).

Wim

[Hoff]

Respectfully, for what reason are you asking these questions?

You're probably either doing some sort of generic research (and if so, see the previous answer and see the OpenVMS FAQ for the upper limits on disks and files on OpenVMS Alpha), or (more likely) you're seeing some sort of a problem or error or oddity with your environment.

If you're seeing problem(s), what would the details and error(s) and command(s) be?

And regardless, do ensure you are on the current version and current ECO of the defragger, and the current ECOs for OpenVMS Alpha V7.3-2.