[Info-vax] HP wins Oracle Itanium case

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In article <k13p6r$v09$1 at dont-email.me>, David Froble <davef at tsoft-inc.com> writes:
>Johnny Billquist wrote:
>> On 2012-08-22 15:05, ChrisQ wrote:
>>> In the end though, what get's stored on disk is a stream of bytes at the
>>> lowest
>>> level. To make the most flexible use of that, an interface to that
>>> stream should
>>> be provided, even if there are other structures eg: rms, above. Someone
>>> else
>>> said that the qio interface could be used, but seem to remember that as
>>> being
>>> fairly arcane at the time.
>> 
>> Uh... No. At the lowest level of a disk, you do *not* store a stream of 
>> bytes. Where on earth did you get that from? At the lowest level, a disk 
>> deals with disk *blocks*. You read/write one block at a time.
>> Blocks are typically 512 bytes, or possibly 2048 or 4096 bytes nowadays.
>> 
>> I don't offhand feel safe enough to comment VMS specific here, but 
>> atleast in RSX, QIO *is* the interface used to read/write blocks. RMS is 
>> a library on top of this, and RMS uses QIO internally to actually 
>> perform the disk activities.
>> 
>> As such, you can also implement any other file structure in RSX pretty 
>> easily. You only need provide the same interface specified at the QIO 
>> level, and you're set.
>> 
>> And actually, all the I/O operations done by RMS is done to the disk 
>> device, but are in reality caught by the ACP, which then do the physical 
>> I/O operations to the disk.
>> So, write another ACP, that implements your file system, and just plug 
>> it in, and off you go.
>> 
>>> I guess the argument is whether structure like rms should be integrated
>>> into the
>>> filesystem, or whether it should be a separate layer. Provided it's done
>>> right,
>>> either approach should be equally valid afaics...
>> 
>> I'm sure there must be some way of going around RMS in VMS, so is it 
>> really integrated in the file system? Can't you dump a file as the disk 
>> blocks doing analyze, for example. What relation do RMS have there, 
>> since you are ignoring the file attributes, and process the blocks 
>> exactly as they happen to be stored on the disk?
>> 
>>     Johnny
>> 
>> 
>
>On ODS type disks, on VMS, it's my understanding that the directories are RMS 
>files, or sort of ..   Thus the impression that VMS and RMS are tied together. 
>In a way they are, but, it is possible to have other files, I do, and don't 
>depend very much on RMS.  Used RMS for the filename parsing, no sense 
>re-inventing the wheel, and if it changes, RMS will already be modified for you. 
>  But after that, no calls to RMS.

Directory files are handled in the XQP, not by RMS.  Granted, there are
RMS services to manipulate directories but that'd be like saying that C's
mkdir() is a part of the file system

-- 
VAXman- A Bored Certified VMS Kernel Mode Hacker    VAXman(at)TMESIS(dot)ORG

Well I speak to machines with the voice of humanity.