G
Guest
Am a New User and have XP Home therefore cannot encrypt. Have SanDisk 1Gb
flash drive using CruzerLock2 encrypt software. Had read a number of posts
and related links indicating vulnerability to disk errors of FAT file system,
and checked with mfrer of CruzerLock software (encryptX) on this issue.
Thought you would like to have their reply, for your information.
TO QUOTE: Applications stored on physical media use whatever file system the
operating system tells it to. CruzerLock 2 is only available on the Windows
platform and USB drives under Windows can only be formatted with either the
FAT16 or FAT32 file systems. Our software does not interact with the
physical media layer directly, so any perceived disk error vulnerabilities
would be caused between the operating system and its file system not by any
use of our software.
It is possible for a user to convert a Cruzer’s FAT 16/32 partition to NTFS.
Since NTFS is designed for performance, it uses “write behind†technology to
speed the access to the drive. This means that no matter how the application
software tries to write data to the drive, that data is always stored in a
memory buffer and written out to the disk at the system’s convenience.
Because of this, a user must always use the Safe Device Removal dialog to
remove the Cruzer drive from the system if they want to be sure that all of
the data has been written to the drive first.
The CruzerLock2 software is designed to guarantee that the archive is always
readable even after device I/O errors, as long as the file system for the
underlying media guarantees that all the data is written to the media on
demand. The FAT 16/32 file systems provide this guarantee. This can be
demonstrated by starting an encrypt operation to the Cruzer drive and pulling
the drive from the system in the middle of the operation. Upon returning the
drive to the system, the archive on the drive will still be readable and all
data that had been written to the archive up until the point of removal is
intact. NTFS, however, does not guarantee that the data is written on demand.
If you repeat the same test condition with a drive formatted with NTFS, the
archive is corrupted and the user’s encrypted data is lost. Worse, if the
user had selected that the original files be removed after encryption, then
not only is the archive corrupted beyond repair, but the original user data
is gone too.
This problem becomes worse with the potential for poor quality USB ports.
We’ve noted at least a handful of systems to date where the USB port reports
that the drive is removed from the system even when it is not. So even for
those users who are conscientious enough to always use Safe Device Removal
with an NTFS file system still have the potential for troubles.
With some applications/drivers, it is also possible to convert a Cruzer’s
file system to a non-Windows format, ‘though there is no guarantee that our
software’s encryption algorithm and the archive’s file structure will remain
readable and functional. UNQUOTE
Since the above response was received, the encryptX technical support person
also sent the following e-mail:
QUOTE: As I reread my reply, I realized it doesn't really answer the
question of whether FAT is vulnerable to disk errors. FAT might very well be
susceptible to errors. Unfortunately there is little choice when using USB
flash drives on a Windows operating system. FAT16/32 and NTFS are the file
systems that Windows supports. Since NTFS doesn't write data on demand we
must use FAT16/32. UNQUOTE
I think the above explanations have made the subject a lot clearer to me and
provide a good background when deciding which file system to use for a
specific purpose with my computer setup.
flash drive using CruzerLock2 encrypt software. Had read a number of posts
and related links indicating vulnerability to disk errors of FAT file system,
and checked with mfrer of CruzerLock software (encryptX) on this issue.
Thought you would like to have their reply, for your information.
TO QUOTE: Applications stored on physical media use whatever file system the
operating system tells it to. CruzerLock 2 is only available on the Windows
platform and USB drives under Windows can only be formatted with either the
FAT16 or FAT32 file systems. Our software does not interact with the
physical media layer directly, so any perceived disk error vulnerabilities
would be caused between the operating system and its file system not by any
use of our software.
It is possible for a user to convert a Cruzer’s FAT 16/32 partition to NTFS.
Since NTFS is designed for performance, it uses “write behind†technology to
speed the access to the drive. This means that no matter how the application
software tries to write data to the drive, that data is always stored in a
memory buffer and written out to the disk at the system’s convenience.
Because of this, a user must always use the Safe Device Removal dialog to
remove the Cruzer drive from the system if they want to be sure that all of
the data has been written to the drive first.
The CruzerLock2 software is designed to guarantee that the archive is always
readable even after device I/O errors, as long as the file system for the
underlying media guarantees that all the data is written to the media on
demand. The FAT 16/32 file systems provide this guarantee. This can be
demonstrated by starting an encrypt operation to the Cruzer drive and pulling
the drive from the system in the middle of the operation. Upon returning the
drive to the system, the archive on the drive will still be readable and all
data that had been written to the archive up until the point of removal is
intact. NTFS, however, does not guarantee that the data is written on demand.
If you repeat the same test condition with a drive formatted with NTFS, the
archive is corrupted and the user’s encrypted data is lost. Worse, if the
user had selected that the original files be removed after encryption, then
not only is the archive corrupted beyond repair, but the original user data
is gone too.
This problem becomes worse with the potential for poor quality USB ports.
We’ve noted at least a handful of systems to date where the USB port reports
that the drive is removed from the system even when it is not. So even for
those users who are conscientious enough to always use Safe Device Removal
with an NTFS file system still have the potential for troubles.
With some applications/drivers, it is also possible to convert a Cruzer’s
file system to a non-Windows format, ‘though there is no guarantee that our
software’s encryption algorithm and the archive’s file structure will remain
readable and functional. UNQUOTE
Since the above response was received, the encryptX technical support person
also sent the following e-mail:
QUOTE: As I reread my reply, I realized it doesn't really answer the
question of whether FAT is vulnerable to disk errors. FAT might very well be
susceptible to errors. Unfortunately there is little choice when using USB
flash drives on a Windows operating system. FAT16/32 and NTFS are the file
systems that Windows supports. Since NTFS doesn't write data on demand we
must use FAT16/32. UNQUOTE
I think the above explanations have made the subject a lot clearer to me and
provide a good background when deciding which file system to use for a
specific purpose with my computer setup.