As Image for Windows is doing a full backup, does it verify the checksum (cyclic redundancy check) for every file as it reads them? Just wondering if doing a full backup of a hard drive is also verifying that files are not corrupt.
Thanks,
Skyglider
Does IFW verify checksum for files when doing a backup?
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TeraByte Support
- Posts: 3627
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Re: Does IFW verify checksum for files when doing a backup?
1 - it doesn't read files, it reads sectors.
2 - there is no crc on files to check. the only time that happens is when
an implementation on the file system (compression, part of the fs design)
which would be handled by the OS when files are read, but doesn't affect the
block level backups, everything goes back the way it was when backed up.
What you're probably referring to or thinking about is the crc on sector
data, and that is handled automatically by the firmware in the drive. If
the crc fails and it can't read the data (it retries which is why it can
take a while for the drive to respond), it will report a failure.
As far as the backup, if you validate byte-for-byte, all data is read back
to new memory locations and compared to what was backed up to ensure data
integrity. See http://www.terabyteunlimited.com/kb/article.php?id=350
"Skyglider" wrote in message news:9783@public.image...
As Image for Windows is doing a full backup, does it verify the checksum
(cyclic redundancy check) for every file as it reads them? Just wondering
if doing a full backup of a hard drive is also verifying that files are not
corrupt.
Thanks,
Skyglider
2 - there is no crc on files to check. the only time that happens is when
an implementation on the file system (compression, part of the fs design)
which would be handled by the OS when files are read, but doesn't affect the
block level backups, everything goes back the way it was when backed up.
What you're probably referring to or thinking about is the crc on sector
data, and that is handled automatically by the firmware in the drive. If
the crc fails and it can't read the data (it retries which is why it can
take a while for the drive to respond), it will report a failure.
As far as the backup, if you validate byte-for-byte, all data is read back
to new memory locations and compared to what was backed up to ensure data
integrity. See http://www.terabyteunlimited.com/kb/article.php?id=350
"Skyglider" wrote in message news:9783@public.image...
As Image for Windows is doing a full backup, does it verify the checksum
(cyclic redundancy check) for every file as it reads them? Just wondering
if doing a full backup of a hard drive is also verifying that files are not
corrupt.
Thanks,
Skyglider
Re: Does IFW verify checksum for files when doing a backup?
>> Postby TeraByte Support » Tue Jun 16, 2015 2:31 pm
1 - it doesn't read files, it reads sectors.
2 - there is no crc on files to check. the only time that happens is when
an implementation on the file system (compression, part of the fs design)
which would be handled by the OS when files are read, but doesn't affect the
block level backups, everything goes back the way it was when backed up.
What you're probably referring to or thinking about is the crc on sector
data, and that is handled automatically by the firmware in the drive. If
the crc fails and it can't read the data (it retries which is why it can
take a while for the drive to respond), it will report a failure.
As far as the backup, if you validate byte-for-byte, all data is read back
to new memory locations and compared to what was backed up to ensure data
integrity. See http://www.terabyteunlimited.com/kb/article.php?id=350 <<
...............................
Thanks for the quick response. Understand now.
1 - it doesn't read files, it reads sectors.
2 - there is no crc on files to check. the only time that happens is when
an implementation on the file system (compression, part of the fs design)
which would be handled by the OS when files are read, but doesn't affect the
block level backups, everything goes back the way it was when backed up.
What you're probably referring to or thinking about is the crc on sector
data, and that is handled automatically by the firmware in the drive. If
the crc fails and it can't read the data (it retries which is why it can
take a while for the drive to respond), it will report a failure.
As far as the backup, if you validate byte-for-byte, all data is read back
to new memory locations and compared to what was backed up to ensure data
integrity. See http://www.terabyteunlimited.com/kb/article.php?id=350 <<
...............................
Thanks for the quick response. Understand now.