Thread: Re: [mail] Re: Windows Build System

Re: [mail] Re: Windows Build System

From
"Dave Page"
Date:

> -----Original Message-----
> From: Tom Lane [mailto:tgl@sss.pgh.pa.us]
> Sent: 30 January 2003 15:56
> To: Hannu Krosing
> Cc: Vince Vielhaber; Dave Page; Ron Mayer;
> pgsql-hackers@postgresql.org
> Subject: Re: [mail] Re: [HACKERS] Windows Build System
>
>
> In the pull-the-plug case you have to worry about what is on
> disk at any given instant and whether you can make all the
> bits on disk consistent again.  (And also about whether your
> filesystem can perform the equivalent exercise for its own
> metadata; which is why we are questioning Windows here.

I've never (to my knowledge) lost any data following a powerfail or
system crash on a system using NTFS - that has always seemed pretty
solid to me. By comparison, I have lost data on ext2 filesystems on a
couple of occasions.

More info at:

http://www.ntfs.com/data-integrity.htm
http://www.pcguide.com/ref/hdd/file/ntfs/relRec-c.html

Obviously this goes out of the window is the user chooses to run on
FAT/FAT32 partitions. I think that it should be made *very* clear in any
future documentation that the user is strongly advised to use only NTFS
filesystems.

I realise this is not proof that it actually works of course...

Regards, Dave.


Re: [mail] Re: Windows Build System

From
Tom Lane
Date:
"Dave Page" <dpage@vale-housing.co.uk> writes:
> I've never (to my knowledge) lost any data following a powerfail or
> system crash on a system using NTFS ...
> Obviously this goes out of the window is the user chooses to run on
> FAT/FAT32 partitions. I think that it should be made *very* clear in any
> future documentation that the user is strongly advised to use only NTFS
> filesystems.

This is exactly the kind of thing we have to learn about and document.
Which Windows releases can be trusted, which filesystems are okay,
what other stuff do you need to stay away from?
        regards, tom lane


Re: [mail] Re: Windows Build System

From
Greg Copeland
Date:
On Thu, 2003-01-30 at 14:27, Dave Page wrote:
> > -----Original Message-----
> > From: Tom Lane [mailto:tgl@sss.pgh.pa.us] 
> > Sent: 30 January 2003 15:56
> > To: Hannu Krosing
> > Cc: Vince Vielhaber; Dave Page; Ron Mayer; 
> > pgsql-hackers@postgresql.org
> > Subject: Re: [mail] Re: [HACKERS] Windows Build System 
> > 
> > 
> > In the pull-the-plug case you have to worry about what is on 
> > disk at any given instant and whether you can make all the 
> > bits on disk consistent again.  (And also about whether your 
> > filesystem can perform the equivalent exercise for its own 
> > metadata; which is why we are questioning Windows here.  
> 
> I've never (to my knowledge) lost any data following a powerfail or
> system crash on a system using NTFS - that has always seemed pretty
> solid to me. By comparison, I have lost data on ext2 filesystems on a
> couple of occasions.
> 
> More info at:
> 
> http://www.ntfs.com/data-integrity.htm
> http://www.pcguide.com/ref/hdd/file/ntfs/relRec-c.html
> 
> Obviously this goes out of the window is the user chooses to run on
> FAT/FAT32 partitions. I think that it should be made *very* clear in any
> future documentation that the user is strongly advised to use only NTFS
> filesystems.
> 
> I realise this is not proof that it actually works of course...
> 

I have lost entire directory trees (and all associated data) on NTFS
before.  NTFS was kind enough to detect an inconsistency during boot and
repaired the file system by simply removing any and all references to
the top level damaged directory (on down).  Sure, the file system was in
a known good state following the repair but the 2-days to recover from
it, pretty much stunk!

I would also like to point out that this damage/repair occurred on a
RAID-5 box (hardware, not software).  As the repairs placed the file
system back into known good state, the raid hardware was happy to obey. 
Guess what, it did!  :(  Make no mistake about it.  You can easily lose
large amounts of data on NTFS.

You also compared NTFS with ext2.  That's not exactly fair.  Better you
should compare NTFS with ext3, XFS, JFS, ReiserFS.  It's a better, more
fair comparison, as now we're talking about the same category of file
system.


-- 
Greg Copeland <greg@copelandconsulting.net>
Copeland Computer Consulting