Logical block protection for tape interchange
View Patent ↗A two part process is used for modifying records to be written and retrieved from tape devices. A record is appended with a cyclic redundancy check and a string of zeros. Submitting the entire record to tape drives which are logical block protection enabled will result in no change. For drives that are not LBP enabled, the string of zeros at the end of the record is removed. In addition to determining whether a drive is LBP compliant, a determination may be made as to whether a drive is a linear tape open drive from a particular manufacturer. Linear tape open drives may behave similarly as drives which may not be enabled with logical block protection.
1. A method for writing data to a tape drive, the method comprising:
accessing a record to write to the tape drive;
appending a cyclic redundancy check (CRC) to the end of the record;
appending a string of zeros to the end of the CRC;
detecting whether the tape drive may enable logical block protection (LBP);
removing the string of zeros when the tape drive may not enable LBP;
providing the record to the tape drive to be written;
reading the record from the tape drive; and
appending zeros to the end of the record after reading the record when the tape drive does not enable LBP.
2. The method of claim 1 , further comprising enabling the tape drive for LBP.
3. The method of claim 1 , wherein the CRC is thirty-two bit.
4. The method of claim 1 , wherein the string of zeros is a thirty two bit zero.
5. The method of claim 1 , wherein the tape drive will write the record and append a 32 bit zero when the tape drive does not enable logical block protection.
6. The method of claim 1 , wherein the tape drive will write the record and not append the record when the tape drive does enable logical block protection.
7. The method of claim 1 , further comprising detecting whether the tape drive is a linear-tape-open drive that will append a string of zeroes to the record; and removing the string of zeros when the tape drive is a linear-tape-open drive that will append a string of zeroes to the record.
8. The method of claim 1 , wherein the tape drive will provide the record and not the string of zeros from the record when the tape drive does enable logical block protection.
9. The method of claim 1 , wherein the string of zeros are not appended to the record after reading the record when the tape drive may enable LBP and when LBP is enabled on the tape drive.
10. A non-transitory computer readable storage medium having embodied thereon a program executable by a processor performing a method for writing data to a tape drive, the method comprising:
accessing a record to write to the tape drive;
appending a cyclic redundancy check (CRC) to the end of the record;
appending a string of zeros to the end of the CRC;
detecting whether the tape drive may enable logical block protection (LBP);
removing the string of zeros when the tape drive may not enable LBP;
providing the record to the tape drive to be written;
reading the record from the tape drive; and
appending zeros to the end of the record after reading the record when the tape drive does not enable LBP.
11. The non-transitory computer readable storage medium of claim 10 , the program further executable to enable the tape drive for LBP.
12. The method of claim 10 , wherein the CRC is thirty-two bit.
13. The non-transitory computer readable storage medium of claim 10 , wherein the string of zeros is a thirty two bit zero.
14. The non-transitory computer readable storage medium of claim 10 , wherein the tape drive will write the record and append a 32 bit zero when the tape drive may not enable logical block protection.
15. The non-transitory computer readable storage medium of claim 10 , wherein the tape drive will write the record and not append the record when the tape drive may enable logical block protection.
16. The non-transitory computer readable storage medium of claim 10 , the program further executable to detect whether the tape drive is a linear-tape-open drive that will append a string of zeroes to the record; and removing the string of zeros when the tape drive is a linear-tape-open drive that will append a string of zeroes to the record.