Related to usbdrive

[Alma J Wetzker]

David A. Bandel wrote:
> On Sun, 11 Jan 2004 08:50:49 -0800
> "Net Llama!" <netllama at linux-sxs.org> wrote:
> 
> 
>>>On 01/11/04 08:15, Chong Yu Meng wrote:
>>>
>>>>David A. Bandel wrote:
>>>>
>>>>>>If I recall correctly, FAT was never a journalled file system, was
>>>>
>>>>it>> ? And FAT32?
>>>>>
>>>>>This can't be a real question.  Of course not.  It was designed for
>>>>
>>>>a> DISK Operating System (DOS). Nothing was designed to be kept in
>>>>memory> except the data you were working on.  I don't believe M$ has
>>>>_any_> journalling file systems (unless they've recently stolen one).
>>>>
>>>>Interesting ! An ex-colleague once said to me that NTFS was a
>>>>journalled file system. Was he blowing smoke ? If he was, I'll need
>>>>to have a word with his employer ...
>>>
>>>I've also heard rumor that NTFS is a journaling FS.
> 
> Since when?  Must be recent.  Of course, I haven't had to deal with M$
> crap for a long time now.  But NTFS under NT4 was most definitely _not_
> journaled.  In fact, recovery could take a very long time (but was
> usually just reinstall).  I don't call that journaled.
> 
> Anyone still have to deal with this junk?  Can you replace the NT (XP,
> whatever) kernel while the system is running?  Never used to be
> possible.
> 

You still can't swap out parts of winders while it is running, you need to 
reboot.  Problem is, M$ tends to do complete rewrites of things and say that 
nothing changed or say that it is different when nothing has changed.


from: http://www.ntfs.com/data-integrity.htm
Recovering Data with NTFS

NTFS views each I/O operation that modifies a system file on the NTFS volume 
as a transaction, and manages each one as an integral unit. Once started, the 
transaction is either completed or, in the event of a disk failure, rolled 
back (such as when the NTFS volume is returned to the state it was in before 
the transaction was initiated).

To ensure that a transaction can be completed or rolled back, NTFS records the 
suboperations of a transaction in a log file before they are written to the 
disk. When a complete transaction is recorded in the log file, NTFS performs 
the suboperations of the transaction on the volume cache. After NTFS updates 
the cache, it commits the transaction by recording in the log file that the 
entire transaction is complete.

Once a transaction is committed, NTFS ensures that the entire transaction 
appears on the volume, even if the disk fails. During recovery operations, 
NTFS redoes each committed transaction found in the log file. Then NTFS 
locates the transactions in the log file that were not committed at the time 
of the system failure and undoes each transaction suboperation recorded in the 
log file. Incomplete modifications to the volume are prohibited.

NTFS uses the Log File service to log all redo and undo information for a 
transaction. NTFS uses the redo information to repeat the transaction. The 
undo information enables NTFS to undo transactions that are not complete or 
that have an error.


     -- Alma