RE: Using DVD-RAM drive -- MIDRANGE-L

Compression (DTACPR) is usually a software function, although it can be in hardware if supported - help says that optical devices do not have this support. Compaction (COMPACT) is on the hardware. There can be a combination of both on hardware if supported. Al B. would probably know whether this is a good idea.

See the help for each parameter for more details - there's more than what I've said here.

HTH
Vern

At 07:46 AM 2/2/2005, you wrote:

> -----Original Message-----
> From: midrange-l-bounces@xxxxxxxxxxxx
> [mailto:midrange-l-bounces@xxxxxxxxxxxx]On Behalf Of Hall, Philip
> Sent: Tuesday, February 01, 2005 2:47 PM
> To: Midrange Systems Technical Discussion
> Subject: RE: Using DVD-RAM drive
>
>
> Charles,
>
> > Interesting that the compression ratio when writing to
> > the save file is so much worse than the compression ratio
> > when writing to the DVD-RAM> Anybody know why this is not the case?
>
> In all seriousness this time;
>
> SAVF's don't 'know' what media the may (or may not) end up on
> - and as I understand it, the data compression ratio is also
> tied in to the drive/media being used at that very point the
> save is occurring.
>
> All that's really happened (when doing a SAVLIB (DEV(*SAVF))
> is probably LZH compression on the contents of the SAVF -
> i.e. something that is not device/media specific - but to see
> a big compression ratio you'd need to specify where (the
> device/media specifics) the savf will end up, I guess.

Except the DVD-RAM drive doesn't have any compression built in. So in either case, it's OS/400 doing the compression when the DTACPR(*YES) is specified.


>
> I can't get to a screen at the moment, but does the
> SAVSAVFDTA have a DTACPR() option - or similar? Or is there
> another way to save the savf that will allow device specific
> compression?
>
> --phil
>

SAVSAVFDTA has a COMPACT(*DEV | *NO) param. But as mentioned above, this has no effect since the DVD-RAM drive doesn't offer any hardware compression/compaction.


Charles

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