Multi-protocol storage appliance that provides integrated support for file and block access protocols

• US 20040030668A1
• Filed: 08/09/2002
• Published: 02/12/2004
• Est. Priority Date: 08/09/2002
• Status: Active Grant

• Current Assignee: Network Appliance Incorporated (NetApp, Inc.)
• Original Assignee: Network Appliance Incorporated (NetApp, Inc.)
• Inventors: Lee, Herman, Pawlowski, Brian, Pittman, Joseph C., Srinivasan, Mohan, Rajan, Vijayan
• Granted Patent: US 7,873,700 B2
• Time in Patent Office: Days
• US Class Current: 707/1
• CPC Class Codes: G06F 16/10 File systems; File servers
• 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 3/0661 Format or protocol conversion arrangements
• CPC Class Codes: G06F 3/0664 at device level, e.g. emulation of a storage device or system
• CPC Class Codes: G06F 3/067 Distributed or networked storage systems, e.g. storage area networks [SAN], network attached storage [NAS]
• CPC Class Codes: H04L 63/10 for controlling access to devices or network resources

Abstract

A multi-protocol storage appliance serves file and block protocol access to information stored on storage devices in an integrated manner for both network attached storage (NAS) and storage area network (SAN) deployments. A storage operating system of the appliance implements a file system that cooperates with novel virtualization modules to provide a virtualization system that “virtualizes” the storage space provided by the devices. Notably, the file system provides volume management capabilities for use in block-based access to the information stored on the devices. The virtualization system allows the file system to logically organize the information as named file, directory and virtual disk (vdisk) storage objects to thereby provide an integrated NAS and SAN appliance approach to storage by enabling file-based access to the files and directories, while further enabling block-based access to the vdisks.

Claims

1. A multi-protocol storage appliance adapted to serve file and block protocol access to information stored on storage devices in an integrated manner for both network attached storage (NAS) and storage area network (SAN) deployments, the appliance comprising:

a storage operating system adapted to implement a file system cooperating with virtualization modules to virtualize a storage space provided by the storage devices.

2. The multi-protocol storage appliance of claim 1 wherein the file system logically organizes the information as files, directories and virtual disks (vdisks) to thereby provide an integrated NAS and SAN appliance approach to storage by enabling file-based access to the files and directories, while further enabling block-based access to the vdisks.

3. The multi-protocol storage appliance of claim 1 wherein the virtualization modules comprises a vdisk module and a Small Computer Systems Interface (SCSI) target module.

4. The multi-protocol storage appliance of claim 3 wherein the vdisk module is layered on the file system to enable access by administrative interfaces in response to a system administrator issuing commands to the multi-protocol storage appliance.

5. The multi-protocol storage appliance of claim 4 wherein the administrative interfaces include a user interface (UI).

6. The multi-protocol storage appliance of claim 5 wherein the vdisk module manages the SAN deployments by implementing a set of vdisk commands issued through the UI.

7. The multi-protocol storage appliance of claim 6 wherein the vdisk commands are converted to primitive file system operations that interact with the file system and the SCSI target module to implement the vdisks.

8. The multi-protocol storage appliance of claim 7 wherein the SCSI target module initiates emulation of a disk or logical unit number (lun) by providing a mapping procedure that translates the lun into a vdisk.

9. The multi-protocol storage appliance of claim 8 wherein the SCSI target module provides a translation layer between a SAN block space and a file system space.

10. The multi-protocol storage appliance of claim 1 wherein the virtualized storage space allows SAN and NAS storage objects to coexist with respect to global space management by the file system.

11. The multi-protocol storage appliance of claim 10 wherein the file system cooperates with the virtualization modules to provide a virtualization system that provides reliability guarantees for the SAN and NAS storage objects coexisting in the virtualized storage space.

12. The multi-protocol storage appliance of claim 1 wherein the file system provides volume management capabilities for use in block-based access to the information stored on the storage devices.

13. The multi-protocol storage appliance of claim 12 wherein the storage devices are disks.

14. The multi-protocol storage appliance of claim 1 wherein the file system provides (i) file system semantics, such as naming of storage objects, and (ii) functions associated with a volume manager.

15. The multi-protocol storage appliance of claim 14 wherein the functions associated with the volume manager comprise at least one of:

aggregation of the storage devices;

aggregation of storage bandwidth of the devices; and

reliability guarantees, such as mirroring or redundant array of independent disks (RAID).

16. A method for providing storage service relating to organization of information stored on storage devices coupled to a multi-protocol storage appliance, the method comprising the steps of:

virtualizing a storage space provided by the storage devices using a file system in cooperating relation with virtualization modules of a storage operating system executing on the multi-protocol storage appliance;

logically organizing the information as file, directory and virtual disk (vdisk) objects in the virtualized storage space to thereby provide an integrated network attached storage (NAS) and storage area network (SAN) appliance approach to storage that allows the objects to coexist with respect to global space management by the file system in the virtualized storage space; and

accessing the logically organized objects stored on the storage devices using block and file access protocols over data paths provided by an integrated network protocol stack of the multi-protocol storage appliance.

17. The method of claim 16 further comprising the step of providing reliability guarantees for the file, directory and vdisk objects coexisting in the virtualized storage space.

18. A storage operating system of a multi-protocol storage appliance configured to provide storage service relating to organization of information stored on storage devices coupled to the appliance, the storage operating system comprising:

an integrated network protocol stack that provides data paths for clients to access the information stored on the multi-protocol storage appliance using block and file access protocols; and

a file system cooperating with virtualization modules to virtualize a storage space provided by the storage devices.

19. The storage operating system of claim 18 wherein the file system logically organizes the information as files, directories and virtual disks (vdisks) to thereby provide an integrated network attached storage (NAS) and storage area network (SAN) appliance approach to storage using file-based and block-based access protocols.

20. The storage operating system of claim 19 wherein the block-based access protocols include Small Computer Systems Interface (SCSI) based protocols, such as SCSI encapsulated over a Transport Control Protocol (iSCSI) and SCSI encapsulated over Fibre Channel (FCP).

21. The storage operating system of claim 20 wherein the integrated network protocol stack comprises:

network protocol layers;

a file system protocol layer that interfaces to the network protocol layers and provides file-based protocol access to the files and directories organized by the file system; and

an iSCSI driver disposed over the network protocol layers to provide block-based protocol access to the vdisks organized by the file system.

22. The storage operating system of claim 21 wherein the integrated network protocol stack further comprises a virtual interface layer that provides direct access transport capabilities for a file access protocol of the file system protocol layer.

23. The storage operating system of claim 21 wherein the integrated network protocol stack further comprises a Fibre Channel (FC) driver adapted to receive and transmit block access requests to access the vdisks organized by the file system.

24. The storage operating system of claim 23 wherein the FC and iSCSI drivers provide FC-specific and iSCSI-specific access control to the vdisks and further manage exports of vdisks to iSCSI and FCP when accessing the vdisks on the multi-protocol storage appliance.

25. A method for serving file and block protocol access to information stored on storage devices of a multi-protocol storage appliance in an integrated manner for both network attached storage (NAS) and storage area network (SAN) deployments, the method comprising the steps of:

providing NAS services using (i) a network adapter connecting the appliance to a first network and (ii) file system capabilities that allow the appliance to respond to file-based requests issued by a NAS client to access the stored information as files; and

providing SAN services using (i) a network target adapter coupling the appliance to a second network and (ii) volume management capabilities that allow the appliance to respond to block-based requests issued by a SAN client to access the stored information as virtual disks (vdisks).

26. The method of claim 25 further comprising the steps of:

providing name-based management of the files and vdisks stored on the multi-protocol storage appliance to thereby providing a uniform naming scheme for file-based and block-based storage; and

providing a hierarchical structure of named files and vdisks stored on the storage devices.

27. A method for serving file and block protocol access to storage objects stored on storage devices of a multi-protocol storage appliance in an integrated manner for both network attached storage (NAS) and storage area network (SAN) deployments, the method comprising the steps of:

organizing the storage devices into one or more volumes representing a global storage space;

allowing SAN and NAS storage objects to coexist in the global storage space;

receiving block-based and file-based requests to access the SAN and NAS storage objects at a multi-protocol engine of the storage appliance; and

responding to block-based and file-based requests to access and return the SAN and NAS storage objects.