Method of protecting virtual tape data from accidental loss due to overwriting
View Patent ↗In one embodiment, a system includes a main data system, a virtual tape volume coupled to receive a write request from the main data system, and an accidental loss protection system configured to receive the write request to the virtual tape volume, detect whether the write request overwrites a label of the virtual tape volume, and prevent the overwriting of the label.
1. A system comprising:
a virtual tape volume, coupled to receive a write request from a main data system; and
an accidental loss protection system configured to
detect whether the write request overwrites a label of the virtual tape volume based on at least one previous write request and the write request by determining whether
(i) at least one previous write request wrote user data to the virtual tape volume,
(ii) the write request jumped or rewound to the beginning of the virtual tape volume,
(iii) the virtual tape volume has a label, and
(iv) determining whether content of the write request is user data and not a label;
if the determinations of all of (i), (ii), (iii), and (iv) are positive, then preventing the overwriting of the label; and
if the determinations of at least one of (i), (ii), and (iii), (iv) are negative, then executing the write request.
2. The system of claim 1 , wherein preventing the overwriting of the label further comprises setting the virtual tape to read-only.
3. The system of claim 2 , wherein preventing the overwriting of the label further comprises sending an error message to the mainframe.
4. The system of claim 3 , wherein the error message includes the reason the virtual tape volume prevented the write request.
5. The system of claim 1 , wherein the accidental loss protection system is further configured to operate transparent to a mainframe user or application software.
6. The system of claim 1 , wherein the accidental loss protection system is further configured to allow disabling of overwrite protection.
7. A method comprising:
in a hardware processor:
detecting whether a write request received at a virtual tape volume overwrites a label of the virtual tape volume based on at least one previous write request and the write request by determining whether
(i) at least one previous write request wrote user data to the virtual tape volume,
(ii) the write request jumped or rewound to the beginning of the virtual tape volume,
(iii) the virtual tape volume has a label, and
(iv) determining whether content of the write request is user data and not a label;
if the determinations of all of (i), (ii), (iii), and (iv) are positive, then
preventing the overwriting of the label; and
if the determinations of at least one of (i), (ii), and (iii), (iv) are negative, then executing the write request.
8. The method of claim 7 , wherein preventing the overwriting of the label further comprises setting the virtual tape to read-only.
9. The method of claim 8 , wherein preventing the overwriting of the label further comprises sending an error message to the mainframe.
10. The method of claim 9 , wherein the error message includes the reason the virtual tape volume prevented the write request.
11. The method of claim 7 , further comprising operating transparent to a mainframe user or application software.
12. The method of claim 7 , further comprising enabling or disabling of overwrite protection according to a configuration or an operator command.