[Info-vax] FREESPADRIFT

[David Froble]

Paul Sture wrote:
> On 2016-06-16, lawrencedo99 at gmail.com <lawrencedo99 at gmail.com> wrote:
>> On Friday, June 17, 2016 at 6:24:46 AM UTC+12, Michael Moroney wrote:
>>
>>> Don't forget that Spiralog was newer than ODS-5/ODS-2.  And Spiralog was
>>> to be a different file system for VMS (not a mod to ODS-5) but was 
>>> cancelled.
>> Linux was able to add journalling to an existing filesystem (turning
>> ext2 into ext3). VMS never did the same?
> 
> A mentioned by another poster, work was started on a new filesystem.
> 
> We're back to where you spend the available resources - retrofitting
> a new feature to an existing system or implementing a replacement?
> 
> The existing VMS filesystem doesn't cache writes as much as other file
> systems, and on-disk pointers are built in such a way that a power loss
> doesn't result in the damage you see on other file systems.
> 
> I'd put it that the current VMS filesystem didn't need journalling as
> urgently as other filesystems.
> 
> And yes, the relative certainty that when you write something to disk
> it the current VMS world, it does actually hit the disk, has been a
> limiting factor in performance.
> 

But it sure helped when that $10M in accounts receivable wasn't lost ....