Re: HD Backup

["Bryan J. Smith" <b.j.smith@ieee.org>]

On Sun, 2006-01-01 at 14:05 -0600, Robert G. (Doc) Savage wrote:
> Oh, puhleeeeze Bryan. An unprotected, unenforced, and widely used
> "trademark" is just a word.

First off, did you not notice my tags ...
  "<anal note/not a big deal/just FYI>"

Secondly, it's a legacy word that typically indicates Programmed I/O
(PIO) modes of ATA, _not_ modern Ultra DMA modes.  In fact, half of the
problem with the use of EIDE is the poor and incorrect assumption that
ATA drives can be used in the master/slave relationship.

I'm not trying to criticize you or otherwise insult you, but EIDE is a
technically inappropriate word for the technology -- despite continued
Western Digital marketing.

> You completely missed my point, which was to distinguish EIDE drives
> from their SATA brethren,

ATA is ATA, whether parallel or serial.

> for which external enclosures are still rather uncommon.

ATA is ATA, whether parallel or serial.

And yes, they _do_ have external SATA, as well as SAS.

> Upon further checking, you are correct.

I just meant to be _wary_ of a 5-platter drive.  ;->

> Ahem... What filesystem was?

No, I mean the _official_ Microsoft line is that NTFS is _not_ to be
used for removable or portable media!  In fact, NT's Disk Manager will
_prevent_ you from using NTFS on removable media for a reason.  With an
external fixed disk, NT's Disk Manager isn't able to differentiate, so
that's the only reason it doesn't prevent you from creating a NTFS
filesystem.

> Forgive me for being blunt, Bryan, but this is pure FUD.

No it is _not_!  You can corrupt NTFS volume by merely moving it among
different _Windows_ systems.

> NTFS filesystem corruption, while guaranteed when using the NTFS driver
> that comes with Linux in read/write mode, is nonexistant with the
> commercial Paragon driver.

I'm not talking about Windows v. Linux, I'm talking about the inherent
design flaws of NTFS _itself_!  Yes, there are the various Linux NTFS
user-space implementations that read the NT registry and maintain
SAM/SID correctly.  I haven't used the Paragon driver personally, but if
it does this, then yes, it's "safer."

But NTFS is always a major support issue for portable drives -- even
when using 100% Windows systems!  I've seen this first hand, so I
can_not_ condone your recommendation.

Yes, 99% of Windows administrators are ignorant of this fact of NTFS.
But I've taught the MCSE courses repeatedly, and it's the #1 thing I
make people aware of -- NTFS is _never_ to be used for
removable/portable media.

> Its use is transparent except (as you've noted) for permissions
> and ownership on individual files, a characteristic shared to one degree
> or another whenever files are copied from one type of filesystem to
> another. Of course, the solution to the permissions/ownership
> preservation problem was solved years ago with tar.

This isn't a "permissions" issue.  NTFS is _not_ like UNIX where you
have fixed UID/GID or some "extended attributes" (EAs) in a filesystem
that are numerical values.  Every NTFS filesystem is _tied_ to the
System Accounts Manager (SAM) database that created it -- be it a local
SAM in a system's registry, or a network-wide SAM aka "domain."

This is one of the most grossly misunderstood concepts about NT and the
design of NTFS, one that Microsoft wanted to solve with CarioFS and,
more recently, WinFS.  It is a horrendous design flaw in NTFS itself,
and why NT's own Disk Manager prevents you from creating NTFS volumes on
removable media.

> Not to belabor the point, but we live in the most litigious nation in
> the world. Paragon would not dare market their NTFS for Linux in America
> if there were any possibility of being sued for damages over data
> corruption resulting from its use.

Dude, you're totally missing my point.
I'm talking about NTFS' design, not legal or Linux issues.

> In the real world of daily experience I can point to many dozens of
> NTFS-formatted LaCie external drives in service in USTRANSCOM at Scott
> AFB. Quite a few are used as software distribution sources and backups
> for large numbers of PCs and servers, both non-domain and members of
> multiple domains. The SID & SAM problems you refer to simply haven't
> been seen here.

You've been very lucky then.
Yes, in NT5 (2000/XP/2003) it happens a lot less than in the NT3/4 days.
But the inherit design flaws of NTFS are still there.

> The only problem I've ever seen with any of those LaCie devices was a
> string of bad sectors that developed up near the start of the one active
> partition on the 120GB drive in my unit. This was a purely hardware
> fault which I fixed with a low-level format followed by a certification
> pass to map out bad sectors. I used ddrescue and dd to strip and restore
> the partitions; chkdsk at initial mount took care of the gaps where the
> bad sectors had been.
> Unless I'm terribly mistaken, UDF is a read-only filesystem designed for
> DVDs, CD-Rs, and WORM drives and would not be suitable on an external
> hard drive in Ray's situation.

Yes, you are very much mistaken.  You're thinking of ISO9660.

UDF is _both_ a traditional block read/write filesystem and can be an
pre-mastered/archived filesystem like ISO9660 that is character
recorded.  Most people are ignorant of the fact that UDF _is_ usable as
a regular read/write filesystem, and it does an excellent job of
perserving all sorts of different filesystem extents.

That's why they call it the "Universal Device Format".

In fact, the big hoopla over read/write (as well as recorded) HD-DVD v.
BluRay right now is the fact that HD-DVD continues to use standardize on
UDF, and the BluRay perfers its own, eccentric filesystem (UDF is
secondary).  UDF can and is used for all sorts of portable and removable
filesystems -- including portable fixed disks.

> Lacking an ext3 driver for Windows, NTFS is today the most capable
> journaling filesystem for removable media larger than thumb drives.

But why doesn't Microsoft let you format some devices NTFS?
Tell me that?  ;->

> If you want to freely exchange files between Windows and any other system,
> you MUST use a Windows-supported filesystem simply because Microsoft
> refuses to support non-Windows systems.

But Microsoft _does_ support UDF as of NT5+ (2000+).  Just because you
are not aware of that, please do not dismiss my suggestion to use it.

> (And please don't quibble with me about FAT12/16/32 not being Windows
> filesystems because Microsoft can no longer legally restrict their use
> by non-Windows systems.)

I never mentioned FAT12/16/32.

> I stand by my suggestions to Ray. They're based on real world experience
> I know to be true. Ray is free to accept or reject them without hurting
> my feelings in the slightest.

And my suggestions are not based on "real world experience"?
I leave my statements to hold as they are.
No hacks, no extra filesystem drivers, no history of issues.


-- 
Bryan J. Smith   mailto:b.j.smith@ieee.org
http://thebs413.blogspot.com
------------------------------------------
Some things (or athletes) money can't buy.
For everything else there's "ManningCard."



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