Browse Prior Art Database

Buy-what-you-need and When-you-need-it Data Cartridge

IP.com Disclosure Number: IPCOM000015243D
Original Publication Date: 2001-Sep-01
Included in the Prior Art Database: 2003-Jun-20
Document File: 2 page(s) / 219K

Publishing Venue

IBM

Abstract

Figure 1 shows the preferred embodiment of our invention. A data cartridge load request 10 is received by a human user, a library with a robotic picker, or an automatic cartridge loader (ACL). An NVRAM (NonVolatile Random Access Memory) chip which holds the directory contents of the data cartridge is read 12 via any of several different methods, including (a) the grippers of the robotic picker or the ACL having an interface for reading the NVRAM, or (b) the user, the robotic picker, or the ACL holding the NVRAM against a stationary interface. Specific information about this NVRAM is found in US patent 6,172,833. Then, the contents of the NVRAM are processed by either the host, control unit, or I/O device itself in step 14 , to include both reading the directory contents of the data cartridge and gathering the available capacity in that data cartridge, which may be less than the total capacity if the user only purchased a portion of the total capacity.

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Buy-what-you-need and When-you-need-it Data Cartridge

  Figure 1 shows the preferred embodiment of our invention. A data cartridge load request 10 is received by a human user, a library with a robotic picker, or an automatic cartridge loader (ACL). An NVRAM (NonVolatile Random Access Memory) chip which holds the directory contents of the data cartridge is read 12 via any of several different methods, including (a) the grippers of the robotic picker or the ACL having an interface for reading the NVRAM, or (b) the user, the robotic picker, or the ACL holding the NVRAM against a stationary interface. Specific information about this NVRAM is found in US patent 6,172,833. Then, the contents of the NVRAM are processed by either the host, control unit, or I/O device itself in step 14, to include both reading the directory contents of the data cartridge and gathering the available capacity in that data cartridge, which may be less than the total capacity if the user only purchased a portion of the total capacity.

Step 14 flows in parallel to steps 30 and 16. In step 16, the media is positioned for I/O. This includes mounting the data cartridge and seeking to the I/O region of the cartridge. In step 30, the query is made as to whether there is any write workload in the I/O queue. If there is not, the process flows from step 30 to step 42, where the I/O is performed once the media is positioned in step 16.

If there is write workload in step 30, the process flows to step 32, where the information in the NVRAM chip is used to sum the sizes of all of the files stored in the data cartridge. Then, in step 34, the available capacity is calculated by subtracting the used capacity from the user purchased capacity. The process flows to step 36, where the write workload size is compared against the available capacity calculated in step 34. If the write size is less than the available capacity, the process flows to step 42, where the I/O is performed. If the write size is not less than the available capacity, then the process flows to step 38 where the user purchases additional available capacity which was held in reserv...