[Info-vax] VMS - The new file system. What do we know about it?...

[Kerry Main]

> -----Original Message-----
> From: Info-vax [mailto:info-vax-bounces at rbnsn.com] On Behalf
> Of Dirk Munk via Info-vax
> Sent: 15-Nov-16 3:00 AM
> To: info-vax at rbnsn.com
> Cc: Dirk Munk <munk at home.nl>
> Subject: Re: [Info-vax] VMS - The new file system. What do we
> know about it?...
> 
> Michael Moroney wrote:
> > Dirk Munk <munk at home.nl> writes:
> >
> >> Modern disks of course use the Advanced Format structure,
> with 4kB
> >> blocks/sectors. Using arbitrary 512 byte blocks is possible,
but
> not
> >> very good for performance. Is that taken into consideration?
> >
> > That will have to be a separate project.  From what someone
> here told
> > me other OS's (Linux, Windoze) still use 4K block drives in
512
> byte
> > block emulation mode.  Can anyone verify/refute this?
> >
> > Also, most VMS IO on itanics is through SAN storage servers,
> and they
> > are the ones that have to directly deal with 4K blocks.  I
don't
> know
> > if storage servers themselves present themselves as using 4K
> blocks.
> 
> No they don't as far as I'm aware. Block storage usually
consists
> out of RAID sets, and a RAID set uses a stripe size. For
optimal
> performance you should take the stripe size into consideration
> when formatting a disk.
> 
> >
> > Of course there are directly attached SCSI drives that could
> benefit,
> > plus x86 is a different beast.
> >

The Storage world is rapidly changing. 

On one hand you have smart SAN controllers like 3PAR with rules
based policies that dynamically move data around the SAN based on
tier classification, last used dates / performance criteria.

On the other hand, you have flash based storage and TB level
non-volatile local memory technologies that are rapidly replacing
the need for moving head HDD technologies for most use case
scenario's. Because HDD's still have an edge on capacity, they
are becoming more of a data archive technology.

Fwiw, I have been reading a number of Jim Gray's (RIP) research
papers from 2006 and earlier. Jim was a well-known computer
research scientist who worked for Bell Labs, IBM, DEC and
Microsoft.

Here is a quote from one of his presentations in 2006 - 10 years
ago:

- Tape is Dead
- Disk is Tape
- Flash is Disk
- RAM Locality is King

In the same deck, he also stated "soon 10TB disks will be
available" (Cheap 10TB drives are now available - google "10TB
Seagate")

Jim had a pretty amazing view of the future. 

So, in terms of the new file system in V9/V10, while we recognize
the need for compatibility, as Gretzky would say "skate where the
puck is going to be .. not where it is now"


Regards,

Kerry Main
Kerry dot main at starkgaming dot com