Integrated-circuit implementation of a storage-shelf router and a path controller card for combined use in high-availability mass-storage-device shelves and that support virtual disk formatting

• US 20040148461A1
• Filed: 11/04/2003
• Published: 07/29/2004
• Est. Priority Date: 01/13/2003
• Status: Active Grant

• Current Assignee: Avago Technologies International Sales Pte Limited (Broadcom, Inc.)
• Original Assignee: Sierra Logic Inc (Broadcom, Inc.)
• Inventors: Kompella, Murthy, Wakeley, Matthew Paul, Steinmetz, Joseph Harold
• Granted Patent: US 7,634,614 B2
• Time in Patent Office: Days
• US Class Current: 711/114
• CPC Class Codes: G06F 11/201 between storage system components
• CPC Class Codes: G06F 11/2089 Redundant storage control functionality
• CPC Class Codes: G06F 3/0607 by facilitating the process of upgrading existing storage systems, e.g. for improving compatibility between host and storage device
• CPC Class Codes: G06F 3/0608 Saving storage space on storage systems
• CPC Class Codes: G06F 3/0611 in relation to response time
• CPC Class Codes: G06F 3/0617 in relation to availability
• CPC Class Codes: G06F 3/0619 in relation to data integrity, e.g. data losses, bit errors
• CPC Class Codes: G06F 3/064 Management of blocks
• CPC Class Codes: G06F 3/0658 Controller construction arrangements
• CPC Class Codes: G06F 3/0661 Format or protocol conversion arrangements
• CPC Class Codes: G06F 3/0689 Disk arrays, e.g. RAID, JBOD
• CPC Class Codes: H04L 67/1097 for distributed storage of data in networks, e.g. transport arrangements for network file system [NFS], storage area networks [SAN] or network attached storage [NAS]

Abstract

An integrated circuit implementing a storage-shelf router used alone, or in combination with other storage-shelf routers, and in combination with path controller cards, to interconnect the disks within a storage shelf or disk array to a high-bandwidth communications medium through which data is exchanged between the individual disk drives of the storage shelf and a disk-array controller. In various embodiments, the present invention provides virtual disk formatting by a storage shelf router and the storage shelf in which the storage-shelf is included, to external computing entities, such as disk-array controllers and host computers. By providing virtual disk formatting, a storage-shelf router can provide to a disk-array controller, and other external computing entities, the disk-formatting convention expected by the disk-array controller, even though disk drives and other storage systems that do not conform to the expected formatting conventions may be included in the storage shelf and interconnected to a disk-array controller and other external processing entities via an interface provided by a storage-shelf router. Virtual disk formatting, in addition, allows a storage-shelf router to format a disk drive differently from the disk formatting expected by external computing entities, so that the storage-shelf router can transparently include additional information into disk sectors, such as additional error detection and error-correction information.

Claims

1. A virtual disk formatting system comprising:

a number of mass-storage devices having physical sectors of a first sector length; and

a routing component that provides a virtual disk interface to the mass-storage components by mapping access operations, received from external entities, directed to a virtual disk having virtual sectors of a second sector length to the number of mass-storage devices.

2. The virtual disk formatting system of claim 1 wherein the routing component is an integrated-circuit storage-shelf router.

3. The virtual disk formatting system of claim 2 wherein the storage-shelf router provides a fibre-channel-disk-based virtual disk formatting interface to external entities and maps fibre-channel-disk-based access operations to a number of ATA disk drives included in a storage shelf containing the storage-shelf router.

4. The virtual routing system of claim 1 wherein the routing component includes a processor and firmware/software programs that carry out virtual disk formatting.

5. The virtual disk formatting system of claim 1 wherein virtual sectors are mapped onto contiguous physical sectors, allowing the physical sector and byte address of the first byte of a virtual sector to be calculated, when the second sector length is greater than the first sector length, as:

6. The virtual disk formatting system of claim 5 wherein, when the modulus and difference are both evenly divided by 2, the division and multiplication operations can be replaced with shift operations, and the remainder operation can be replaced by a bit-wise and operation.

7. A virtual disk formatting system comprising:

a number of mass-storage devices having physical sectors of a first sector length; and

a routing component that provides to external entities a first virtual disk interface to the mass-storage components by mapping access operations, received from the external entities, directed to the first virtual disk interface having virtual sectors of a second sector length to an internal, virtual disk interface with internal-virtual-disk-sectors having a third sector length larger than the second sector length, and then mapping the access operations from the internal, virtual disk interface to the number of mass-storage devices.

8. A virtual disk formatting system of claim 7 further including:

including, by the routing component, error detection information within the internal-virtual-disk-interface sectors in order to provide routing-component-mediated error checking.

9. The virtual disk formatting system of claim 8 wherein the error detection information is a longitudinal redundancy check code.

10. The virtual disk formatting system of claim 7 wherein the routing component is an integrated-circuit storage-shelf router.

11. The virtual disk formatting system of claim 10 wherein the storage-shelf router provides a fibre-channel-disk-based virtual disk formatting interface to external processing entities and maps fibre-channel-disk-based access operations to a number of ATA disk drives included in a storage shelf containing the storage-shelf router.

12. The virtual routing system of claim 7 wherein the routing component includes a processor and firmware/software programs that carry out virtual disk formatting.

13. A method for providing a virtual-disk-format interface to processing entities external to a number of mass storage devices, the method comprising:

providing a routing component; and

mapping access operations, received from external entities, directed to a virtual disk having virtual sectors of a second sector length by the routing component to the number of mass-storage devices.

14. The method of claim 13 wherein the routing component is an integrated-circuit storage-shelf router.

15. The method of claim 14 wherein the storage-shelf router provides a fibre-channel-disk-based virtual disk formatting interface to external processing entities and further including:

mapping, by the storage-shelf router, fibre-channel-disk-based access operations to a number of ATA disk drives included in a storage shelf containing the storage-shelf router.

16. The method of claim 13 wherein the routing component includes a processor and firmware/software programs that carry out virtual disk formatting.

17. The method of claim 13 further including:

mapping, by the routing component, virtual sectors onto contiguous physical sectors, allowing the physical sector and byte address of the first byte of a virtual sector to be calculated, when the second sector length is greater than the first sector length, as;

$\mathrm{fsl}=\mathrm{first}<br><br>\text{\hspace{1em}<br><br>}<br><br>\mathrm{sector}<br><br>\text{\hspace{1em}<br><br>}<br><br>\mathrm{length}$$\mathrm{ssl}=\mathrm{second}<br><br>\text{\hspace{1em}<br><br>}<br><br>\mathrm{sector}<br><br>\text{\hspace{1em}<br><br>}<br><br>\mathrm{length}$$\begin{array}{c}\mathrm{modulus}=<br><br>(\mathrm{smallest}<br><br>\text{\hspace{1em}<br><br>}<br><br>\mathrm{number}<br><br>\text{\hspace{1em}<br><br>}<br><br>\mathrm{evenly}<br><br>\text{\hspace{1em}<br><br>}<br><br>\mathrm{divisible}<br><br>\text{\hspace{1em}<br><br>}<br><br>\mathrm{by}<br><br>\text{\hspace{1em}<br><br>}\\ <br><br>\mathrm{both}<br><br>\text{\hspace{1em}<br><br>}<br><br>\mathrm{fsl}<br><br>\text{\hspace{1em}<br><br>}<br><br>\mathrm{and}<br><br>\text{\hspace{1em}<br><br>}<br><br>\mathrm{ssl})/\mathrm{ssl}\end{array}$$\mathrm{difference}=\mathrm{ssl}-\mathrm{fsl}$$\mathrm{physical}<br><br>\text{\hspace{1em}<br><br>}<br><br>\mathrm{sector}=\mathrm{virtual}<br><br>\text{\hspace{1em}<br><br>}<br><br>\mathrm{sector}+\left(\frac{\mathrm{virtual}<br><br>\text{\hspace{1em}<br><br>}<br><br>\mathrm{sector}}{\mathrm{modulus}}\right)$$\mathrm{physical}<br><br>\text{\hspace{1em}<br><br>}<br><br>\mathrm{byte}<br><br>\text{\hspace{1em}<br><br>}<br><br>\mathrm{address}=\mathrm{remainder}<br><br>\left(\frac{\mathrm{virtual}<br><br>\text{\hspace{1em}<br><br>}<br><br>\mathrm{sector}}{\mathrm{modulus}}\right)\times <br><br>\mathrm{difference}$

and, when the second sector length is less than the first sector the physical sector and byte address of the first byte of a virtual sector is calculated, as;

$\mathrm{fsl}=\mathrm{first}<br><br>\text{\hspace{1em}<br><br>}<br><br>\mathrm{sector}<br><br>\text{\hspace{1em}<br><br>}<br><br>\mathrm{length}$$\mathrm{ssl}=\mathrm{second}<br><br>\text{\hspace{1em}<br><br>}<br><br>\mathrm{sector}<br><br>\text{\hspace{1em}<br><br>}<br><br>\mathrm{length}$$\begin{array}{c}\mathrm{modulus}=<br><br>(\mathrm{smallest}<br><br>\text{\hspace{1em}<br><br>}<br><br>\mathrm{number}<br><br>\text{\hspace{1em}<br><br>}<br><br>\mathrm{evenly}<br><br>\text{\hspace{1em}<br><br>}<br><br>\mathrm{divisible}<br><br>\text{\hspace{1em}<br><br>}<br><br>\mathrm{by}\\ <br><br>\mathrm{both}<br><br>\text{\hspace{1em}<br><br>}<br><br>\mathrm{fsl}<br><br>\text{\hspace{1em}<br><br>}<br><br>\mathrm{and}<br><br>\text{\hspace{1em}<br><br>}<br><br>\mathrm{ssl})/\mathrm{ssl}\end{array}$$\mathrm{difference}=\mathrm{fsl}-\mathrm{ssl}$$\mathrm{physical}<br><br>\text{\hspace{1em}<br><br>}<br><br>\mathrm{sector}=\mathrm{virtual}<br><br>\text{\hspace{1em}<br><br>}<br><br>\mathrm{sector}-\left(\frac{\mathrm{virtual}<br><br>\text{\hspace{1em}<br><br>}<br><br>\mathrm{sector}}{\mathrm{modulus}}\right)$$\begin{array}{c}\mathrm{physical}<br><br>\text{\hspace{1em}<br><br>}<br><br>\mathrm{byte}<br><br>\text{\hspace{1em}<br><br>}<br><br>\mathrm{address}=<br><br>\mathrm{remainder}(\mathrm{fsl}-\\ <br><br>\mathrm{remainder}<br><br>\left(\frac{\mathrm{virtual}<br><br>\text{\hspace{1em}<br><br>}<br><br>\mathrm{sector}}{\mathrm{modulus}}\right)\times <br><br>\\ <br><br>\mathrm{difference})/\mathrm{fsl}.\end{array}$

18. The method of claim 17 wherein, when the modulus and difference are both evenly divided by 2, the division and multiplication operations can be replaced with shift operations, and the remainder operation can be replaced by a bit-wise and operation.

19. A method for including additional information in disk sectors of a number of mass-storage devices having a first sector length, the method comprising:

providing a routing component;

mapping, by the routing component, access operations, received from external entities, directed to a first virtual disk interface having virtual sectors of a second sector length to an internal, virtual disk interface with internal-virtual-disk-sectors having a third sector length larger than the second sector length, and then mapping, by the routing component, the access operations from the internal, virtual disk interface to the number of mass-storage devices.

20. The method of claim 19 further including:

including, by the routing component, within the internal-virtual-disk-interface sectors one of;

error-detection information;

additional information that, together with the data contained in the internal-virtual-disk-interface sectors, provides an encrypted version of the data directed to the first virtual disk interface by external processing entities; and

error-detection and error-correction information.