Patent Application
20140164830
A typical computer network may have a backup and recovery system for purposes of restoring data (one or multiple files, for example) on the network to a prior state should the data become corrupted, be overwritten, subject to an attack from a virus, etc. Traditionally, the backup and recovery system may include physical magnetic tape drives that store backup data on magnetic tapes. After a transfer of backup data to a given magnetic tape, the tape may be removed from its tape drive and stored in a secure location, such as in a fireproof safe. The backup and recovery system may alternatively be a virtual tape library-based system that emulates but replaces the physical magnetic tape drive system. With a virtual tape library-based system, virtual cartridges, instead of magnetic tapes, store the backup data.
Referring to
In accordance with some implementations, the storage appliance 108 and the computer system 180 are “physical machines,” or actual machines that are made up of software and hardware. Although each of the storage appliance 108 and the computer system 180 is depicted in
In general, the computer system 180 may include hardware 190, such as one or multiple Central Processing Units (CPUs) 192 and a memory 193 that stores machine executable instructions, application data, and so forth. In general, the memory 193 is a non-transitory memory, which may include semiconductor storage devices, magnetic storage devices, optical storage devices, and so forth.
In addition to the machine executable instructions that form the backup application 182 and the recovery application 184, the computer system 180 may include other sets of machine executable instructions that when executed by the CPU(s) 192 form an operating system for the computer system 180, a graphical user interface (GUI) 188 for interacting with the storage appliance 108, device drivers, and so forth.
The computer system 180 communicates with the storage appliance 108 over a communication link 176, which may include one or multiple buses or other fast interconnects. In this manner, the computer system 180 may communicate with the storage appliance 108 using one or multiple protocols, such as a serial attach Small Computer System Interface (SCSI) bus protocol, a parallel SCSI protocol, a Universal Serial Bus (USB) protocol, a Fibre Channel protocol, an Ethernet protocol, and so forth. Being a physical machine, the storage appliance 108 contains hardware 150, such as one or more CPUs 154; a non-transitory memory 156 that stores machines executable instructions, application data, and so forth; and one or multiple physical drives 155 (optical drives, solid state drives, magnetic storage drives, etc) that store, among other data content, the backup data for the computer system 180.
The storage appliance 108, in general, emulates a physical tape drive system and as such, presents a virtual tape drive system interface to the computer system 180. The virtual tape drive system interface has virtual components that correspond to components of a physical tape drive system. In general, the storage appliance 108 provides one or multiple selectable ports (V-Ethernet, V-Fibre Channel, and so forth) through corresponding interfaces 170 for purposes of presenting virtual entities to the computer system 180. As a more specific example, the storage appliance 108 presents one or multiple virtual tape libraries, called “virtual libraries 120” herein. Example virtual libraries 1201, 120P and 120N are depicted in
Each virtual library 120 has virtual tape cartridge slots (called, “virtual cartridge slots 130” herein), with each virtual cartridge slot 130 being associated with a unit of data called a “virtual cartridge” (i.e., an emulated physical tape cartridge). The storage appliance 108 assigns a unique identifier, or “barcode,” to each virtual cartridge when created, and this barcode is used to track the virtual cartridge. In addition to its virtual cartridge slots 130, the virtual library 120 includes other virtual components, such as one or multiple virtual tape drives 124 used to effect data transfer/restoral; virtual robotics 126 used to move media between the virtual cartridge slots 130 and the virtual drives 124; and a virtual mail slot 122, which is used to transfer the virtual cartridges in and out of the virtual library 120.
As depicted in
In accordance with example implementations disclosed herein, the virtual library 120 has a selectable emulation class, or mode, which allows a given virtual library 120 to be configured to emulate not only a physical tape drive library (as described above) but also allows the virtual library 120 to be configured so that a virtual drive 124 of the virtual library 120 may be used as a boot device for the computer system 180. More specifically, in accordance with some example implementations, a virtual library 120 may be selectably configured to operate in a Compact Disc Read-Only-Memory (CD) drive emulation class, or mode, so that its virtual components (the virtual drive 124, robotics 126, and so forth) are configured accordingly to appear (to the computer system 180) to be the corresponding physical components of a library that employs a CD-ROM drive.
In this manner, the computer system 180 may not have a native ability (e.g., an ability imparted by its firmware) to boot up from a tape drive (either virtual or physical). However, the computer system 180 is able to boot up from an emulated boot up device, such as an emulated CD-ROM drive, as a non-limiting example.
For normal backup and restoration operations, the virtual libraries 120 are configured to be virtual tape libraries, and as such, the applications 180 and 184 perceive the libraries 120 to employ physical tape drives. Therefore, the applications 180 and 184 move the virtual cartridges and read and write to the virtual cartridges by interacting with the virtual tape drive components of these virtual libraries 120. However, a given virtual library 120 may be configured to be in a CD-ROM drive emulation mode, which allows the computer system 180 to boot up from a virtual drive 124 (now emulated a CD-ROM drive) of that virtual library 120.
Remotely booting up from an emulated CD-ROM of the storage appliance 108 may occur in connection with a disaster recovery operation (herein called a “recovery operation”) for the computer system 180 in which software, data, and/or hardware components of the computer system 180 fail, become corrupted, or otherwise cannot be adequately used. In the recovery operation, the computer system 180 boots up from a boot up device-configured virtual drive 124 of the storage appliance 108 and as described further below in example implementations, restores its operation environment as well as recovers data stored on the storage appliance 108.
More specifically, as depicted in
In accordance with some implementations, the system recovery image 134 includes an operating system (OS) boot image and other data to aid in the recovery operation and further facilitate the recovery of backup data from the storage appliance 108: machine executable instructions to restore the recovery application 184, configuration settings, machine executable instructions to restore one or multiple device drives, backup data, and so forth. In accordance with some implementations, the system recovery image 134 may be a One Button Disaster Recovery (OBDR) image, which may be created by the recovery application 184 and stored on the storage appliance 108 in the virtual cartridge 162.
The initiation of a recovery operation may occur in several different ways, depending on the implementation. For example, in accordance with some implementations, the computer system 180 may boot-up from the virtual drive 124P and begin the recovery operation in response to a user pressing a physical button of the storage appliance 108 or a physical button of the computer system 180. As another example, in accordance with other implementations, the computer system 180 may boot-up from the virtual drive 124P and begin the recovery operation in response to a user selecting a software icon that is displayed on a monitor of the computer system 180. In yet other implementations, the computer system 180 may automatically determine when to begin the recovery operation. Thus many variations are contemplated and are within the scope of the appended claims.
The boot-up of the computer system 180 from the virtual drive 124P may proceed as follows. First, the computer system 180 shuts down, or powers off, and then the computer system 180 once again powers up. Upon powering up, the computer system 180 searches the network 100 for boot-up devices and upon discovering the virtual drive 124P, boots up from the virtual drive 124P. In some implementations, the recovery operation may involve the computer system 180 booting up and powering down more than one time. In some implementations, a boot up configuration setting that is stored on the network 100 may indicate a preference to boot up from the virtual drive 124P.
Thus, referring to
Referring back to
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Upon detecting a virtual cartridge that contains a system recovery image 134, the virtual tape library 160 may notify the recovery application 184 to allow a user to make a determination (decision block 408) whether this virtual cartridge is to be used in a future restoration/recovery operation. This notification may be in response to a SCSI READ ELEMENT STATUS command that is generated by the computer system 180. Therefore, in some example implementations, the designation of the virtual cartridge that is used for boot-up (as well as the corresponding virtual library) is made via user input at the computer system 180. In other implementations, the computer system 180 may automatically select a virtual cartridge to be used for boot-up. Thus, many variations are contemplated and are within the scope of the appended claims.
After a determination has been made to identify the virtual cartridge as the boot-up cartridge (decision block 404), the technique 400 includes determining (decision block 412) whether a virtual library associated with the selected virtual cartridge is in a CD-ROM drive or a tape drive emulation mode. If the virtual library is in the tape drive emulation mode, then, pursuant to block 416, the recovery engine 184 changes the emulation mode of the virtual library to a CD-ROM drive emulation mode. As a non-limiting example, the recovery application 184 may effect this change by communicating a small computer system interface (SCSI) MODE SELECT command to the storage appliance 108 to change the emulation mode of the virtual library.
Referring to
Other implementations are contemplated and are within the scope of the appended claims. For example, one or multiple virtual drives may default to being bootable devices, such as CD-ROM devices, in accordance with other implementations. In some implementations, whether configured to emulate a boot device by default or not, the emulation mode of the virtual drive may be changed under certain circumstances. For example, if a certain number of SCSI bus resets occur, a given virtual tape library may be changed from a CD-ROM emulation mode to the tape drive emulation mode. Other variations are contemplated and are within the scope of the appended claims.
While a limited number of examples have been disclosed herein, those skilled in the art, having the benefit of this disclosure, will appreciate numerous modifications and variations therefrom. It is intended that the appended claims cover all such modifications and variations.
| Filing Document | Filing Date | Country | Kind | 371c Date |
|---|---|---|---|---|
| PCT/US2011/056328 | 10/14/2011 | WO | 00 | 1/18/2014 |
