1. A storage system accessible by a computer, comprising:
a disk drive unit comprised of plural logical devices;
a memory module which stores information about the disk drive unit;
a first controller comprised of an interface which provides a file system to the computer to facilitate access of files by the computer; and
a second controller which receives access requests from the computer, wherein:
the first and second controllers, when a write request is made by the computer, looks up in the memory module for information on a logical target device that is a target of the write request and, when the logical target device is set to unwritable, inform to the computer that the logical target device is set to unwritable;
the memory module stores a logical unit table which indicates an association between the logical target device and an allocated logical unit allocated to the logical target device;
where the allocated logical unit allocated to the logical target device is accessible by the computer using the file system;
and where at least one of a first attribute, a second attribute, and a third attribute is set for each logical unit by the file system, the first attribute being set for designating meta logical units used to store meta-information of a file held in the disk drive unit, the second attribute being set for designating file logical units used to store file data, the third attribute being set for designating archive logical units to store file data and to be selectively mountable and unmountable for file access in the disk drive unit;
wherein the interface:
stores a mount table indicating which logical unit is mounted to the file system and indicating whether a write in the logical unit is possible; and
stores a map table indicating an association between the logical target device and the allocated logical unit allocated to the logical target device; and
wherein the interface:
obtains a list of files that are not accessed for a predetermined period, referring to meta-information held in the mete logical units for which the first attribute is set;
creates a Universal Disk Format image containing files on the list of files;
secures a logical targeted device that is capable of storing the Universal Disk Format image;
judges whether or not any logical unit is allocated to the secured logical targeted device;
searches, when no logical unit is allocated to the secured logical targeted device, for a logical unit that is not assigned to any logical device from among logical units in which the third attribute is set, using information stored in the memory module;
obtains, when no logical unit is found that is not assigned to any logical device, information of an oldest logical unit that has not been accessed for a longest period, from among the logical units in which the third attribute is set;
unmounts the oldest logical unit for which the information is obtained off the file system;
instructs to the first controller to allocate at least a portion of the unmounted logical unit as a new logical device;
reflects a result of the allocating to the information about the map table, the information being stored in the memory module;
specifies the logical unit to store the created Universal Disk Format image in the new logical device to which the logical unit is allocated; and
sets information on the new logical device that stores the Universal Disk Format image to unwritable, the information being stored in the memory module.
2. A storage system accessible by a computer, comprising:
a disk drive unit comprised of plural logical devices;
a memory module which stores information about the disk drive unit; and
a controller comprised of an interface which provides a file system to the computer to facilitate access of files by the computer, wherein:
the controller:
obtains, when a write request is made by the computer, information on a logical target device that is a target of a write request, from the memory module; and
when the logical target device is set to unwritable, informs to the computer that the logical target device is set to unwritable; and
where the interface:
obtains a list of files that are not accessed for a predetermined period, referring to meta-information held in the disk drive unit;
secures a logical targeted device that is capable of storing the files of the obtained list of files; and
instructs the controller to store in the secured logical targeted device the files on the list of files, and sets information of the secured logical targeted device that stores the files to unwritable, the information being stored in the memory module.
3. The storage system according to claim 2, wherein:
the memory module stores a logical unit table which indicates an association between a subject logical device and an allocated logical unit allocated to the subject logical device;
where the allocated logical unit allocated to the subject logical device is accessible by the computer using the file system;
and where at least one of a first attribute, a second attribute, and a third attribute is set for each logical unit by the file system, the first attribute being set for designating meta logical units used to store meta-information of a file held in the disk drive unit, the second attribute being set for designating file logical units used to store file data, the third attribute being set for designating archive logical units to store file data and to be selectively mountable and unmountable for access in the disk drive unit; and
wherein the controller controls change of an association between any logical device and corresponding logical unit.
4. The storage system according to claim 2, wherein:
upon receiving a file read request from the computer, the interface obtains information on a logical read-target device that stores the requested file, from meta-information of the logical units in which a first attribute for designating meta logical units used to store meta-information of a file is set;
where the interface judges whether each logical unit is associated with the logical read-target device storing the requested file or not;
and when a read-target logical unit is judged associated with the logical read-target device storing the requested file, the interface obtains a mount paint at which the read-target logical unit is mounted to the disk drive unit; and
the interface opens the requested file in a read mode, using the obtained mount point.
5. The storage system according to claim 2, wherein:
upon receiving a file write request from the computer, the interface obtains information on a logical write-target device that stores the requested file, from meta-information of the logical units in which a first attribute for designating meta logical units used to store meta-information of a file is set;
where the interface judges from information stored in the memory module whether the write-target logical device represented by the obtained information is set to unwritable or not;
when the write-target logical device is set to unwritable, the interface informs to the computer that the write-target logical device is set to unwritable;
when the write-target logical device is set as writable, the interface judges whether any logical unit is associated with the write-target logical device or not;
when no logical unit is associated with the logical device, the interface informs to the computer that the logical unit is not associated with the logical device;
when a write-target logical unit is found associated with the logical device, the interface obtains a mount point at which the write-target logical unit is mounted; and
the interface opens the requested file in a write mode, using the obtained mount point.
6. The storage system accessible by a computer, comprising:
a disk drive unit;
a memory module which stores information about the disk drive unit; and
a controller comprised of an interface which provides a file system to the computer to facilitate access to a file, wherein:
the disk drive unit includes plural logical devices;
when a write request is sent from the computer to access a logical target device, the controller refers to information on the logical target device from the memory module and, when the logical target device is set to unwritable, the controller informs to the computer that the logical target device is set to unwritable; and
the interface selectively mounts on and unmounts off at least one of the logical devices for archival accessstorage;
wherein:
the memory module stores information about an association between the logical target device and an allocated logical unit allocated to the logical target device;
where the allocated logical unit allocated to the logical target device is accessible by the computer to access the logical target device using the file system;
and where at least one of a first attribute, a second attribute, and a third attribute is set for each logical unit by the file system, the first attribute being set for designating meta logical units used to store meta-information of a file held in the disk drive unit, the second attribute being set for designating file logical units used to store file data, the third attribute being set for designating archive logical units to store file data and to be selectively mountable and unmountable for file access in the disk drive unit; and
wherein the controller controls change of an association between any logical device and corresponding logical unit.
7. The storage system according to claim 6, wherein:
the interface, using information stored in the memory module, searches for a logical unit that is not assigned to any logical device from among logical units in which the third attribute is set;
when the interface finds no logical unit that is not assigned to any logical device, the interface obtains information of an oldest logical unit that has not been accessed for a predetermined period from among the logical units in which the third attribute is set;
the interface unmounts the oldest logical unit for which the information is obtained, from the disk drive unit;
the interface instructs to the controller to allocate at least a portion of the unmounted logical unit as a new logical device; and the interface reflects a result of the allocating to the information about the association between the new logical device and the logical unit, the information being stored in the memory module.
8. A storage system accessible by a computer, comprising:
a disk drive unit;
a memory module which stores information about the disk drive unit; and
a controller comprised of an interface which provides a file system to the computer to facilitate access to a file, wherein;
the disk drive unit includes plural logical devices;
when a write request is sent from the computer to access a logical target device, the controller refers to information on the logical target device from the memory module and, when the logical target device is set to unwritable, the controller informs to the computer that the logical target device is set to unwritable;
where the memory module stores information about an association between the logical target device and an allocated logical unit allocated to the logical target device;
where the allocated logical unit allocated to the logical target device is accessible by the computer using the file system;
and where at least one of a first attribute, a second attribute, and a third attribute is set for each logical unit by the file system, the first attribute being set for designating meta logical units used to store meta-information of a file held in the disk drive unit, the second attribute being set for designating the file logical units used to store file data, the third attribute being set for designating archive logical units to store file data and to be selectively mountable and unmountable for file access in the disk drive unit; and
wherein the interface:
obtains information of the logical target device that stores a file contained in the write request, referring to meta-information held in the disk drive unit;
judges whether or not a logical target device that can store the file exists;
when it is judged that a logical target device that can store the file exists, provides an allocated logical unit allocated to the logical target device, and obtains data of the allocated logical unit, and obtains relevant data from the logical target device that stores the file, to store write data and the data of the assigned logical unit in the logical target device to which the logical unit is allocated;
when it is judged that there is no logical target device that can store the file, issues a request to the controller to secure a candidate logical target device that can store the file;
allocates an allocated logical unit to the secured candidate logical target device;
obtains relevant data to store the data in the secured candidate logical target device to which the allocated logical unit is allocated; and
sets information on the secured candidate logical target device that stores the file to unwritable, the information being stored in the memory module.
9. A storage system connected to an interface that provides a file system to a computer, and is accessible by the computer, comprising:
a disk drive unit comprised of plural logical devices;
a memory module which stores information about the disk drive unit; and
a controller which receive an access request from the computer, wherein:
the interface:
obtains a list of files that have not been accessed for a predetermined period, referring to meta-information held in the disk drive unit;
secures a logical target device storing the files from the list of files;
instructs the controller to store the files on the list of files in the secured logical target device;
and sets information on the secured logical target device that stores the files to unwritable, the information being stored in the memory module; and
wherein the controller:
obtains, when a write request is made by the computer, information on the logical target device that is a target of a write request, from the memory module; and
informs, when the logical target device is set to unwritable, a signal to the computer indicating mat the logical target device is set to unwritable.
10. A storage system according to claim 9, wherein:
a controller includes first and second controllers;
a memory module stores a logical unit table which indicates an association between the logical target device and an allocated logical unit allocated to the logical target device;
where the allocated logical unit allocated to the logical target device is accessible by the computer using the file system;
and where at least one of a first attribute, a second attribute, and a third attribute is set for each logical unit by the file system, the first attribute being set for designating mete logical units used to store meta-information of a file held in the disk drive unit, the second attribute being set for designating file logical units used to store file data, and the third attribute being set for designating archived logical units to store file data and to be selectively mountable and unmountable for file access in the disk drive unit;
where the interface stores:
a mount table indicating which logical unit is mounted to the file system and indicating whether a write in the logical unit is possible; and
a map table indicating an association between the logical target device and the allocated logical unit allocated to the logical target device; and
where the interface:
obtains a list of files that are not accessed for a predetermined period, referring to meta-information held in any logical units for which the first attribute is set;
creates a Universal Disk Format image containing files on the list of files;
secures a candidate logical target device that is capable of storing the Universal Disk Format image;
judges whether any predetermined logical unit is allocated to the secured candidate logical target device;
searches, when the no predetermined logical unit is allocated to the secured candidate logical target device, for a logical unit that is not assigned to any logical device from among logical units in which the third attribute is set, using information stored in the memory module;
obtains, when no logical unit is found that is not assigned to any logical device, information of an oldest logical unit that has not been accessed for the longest period from among the logical units in which the third attribute is set;
unmount the oldest logical unit for which the information is obtained off the file system;
instructs to the first controller to allocate at least a portion of the unmounted logical unit as a new logical device;
reflects a result of the allocating to the information being stored in the memory module;
specifies the logical unit to store the created Universal Disk Format image in the new logical device to which the logical unit is allocated; and
sets information on the new logical device that stores the Universal Disk Format image to unwritable, the information being stored in the memory module.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1. A catalytic dehydrogenation process for dehydrogenating an alkane stream comprising:
a) contacting the alkane stream with a back-mixed fluidized bed of catalyst;
b) withdrawing deactivated catalyst from the back-mixed fluidized bed of catalyst;
c) heating the deactivated catalyst to regenerate the catalyst and produce hot regenerated catalyst; and
d) returning the hot regenerated catalyst to the back-mixed fluidized bed of catalyst.
2. The process according to claim 1 in which a fuel is burned in a stream comprising oxygen and in the presence of the deactivated catalyst to heat the deactivated catalyst.
3. The process according to claim 1 in which dehydrogenation of the alkane stream requires a heat of reaction and the hot regenerated catalyst provides the heat of reaction for dehydrogenating the alkane stream.
4. The process according to claim 1 in which the back-mixed fluidized bed of catalyst is substantially isothermal.
5. The process according to claim 1 in which the back-mixed fluidized bed of catalyst has a temperature preferably in the range 500\xb0 to 700\xb0 C.
6. The process according to claim 1 in which the hot regenerated catalyst has a temperature preferably in the range 10\xb0 to 200\xb0 C. hotter than a temperature of the back-mixed fluidized bed of catalyst.
7. The process according to claim 1 in which the back-mixed fluidized bed of catalyst is operated at an absolute pressure preferably in the range 50 kPa to 500 kPa.
8. The process according to claim 1 in which the alkane stream is heated before contact with the fluidized bed of catalyst and in which the alkane stream is heated to a temperature preferably in the range between 50\xb0 C. colder to 50\xb0 C. hotter than a temperature of the back-mixed fluidized bed of catalyst.
9. The process according to claim 1 in which a first product defined as (catalyst mass flow rate\xd7catalyst specific heat capacity)\xd7(temperature of the hot regenerated catalyst-temperature of the back-mixed fluidized bed of catalyst) is substantially equal to a second product defined as moles of the alkane stream converted\xd7molar heat of reaction for dehydrogenation of the alkane stream.
10. The process according to claim 1 in which the alkane stream comprises one of the following: ethane, propane, isobutane, normal butane, pentanes, hexanes, heptanes or octanes.
11. The process according to claim 1 in which the catalyst comprises a support material chosen from the group comprising: alumina, silica, aluminosilicates, aluminophosphates, natural and synthetic zeolites, clays and metal oxides on which is dispersed a metal from the group comprising iron, nickel, chromium, molybdenum, tungsten, palladium, platinum, rhenium and cobalt.
12. A catalytic dehydrogenation system for dehydrogenating a stream of alkanes comprising:
a) a back-mixed fluidized bed reactor for contacting the stream of alkanes with a fluidized bed of catalyst;
b) a first conduit for withdrawing deactivated catalyst from the back-mixed fluidized bed reactor;
c) a regenerator in which the deactivated catalyst is heated to produce hot regenerated catalyst; and
d) a second conduit for returning the hot regenerated catalyst to the back-mixed fluidized bed reactor.
13. The system according to claim 12 in which the regenerator comprises a fixed fluidized bed.
14. The system according to claim 12 in which the regenerator comprises a fast fluidized bed.
15. The system according to claim 12 in which the back-mixed fluidized bed reactor is substantially isothermal.
16. The system according to claim 12 in which the back-mixed fluidized bed reactor comprises an upper zone and a lower zone and the lower zone is more back-mixed than the upper zone.
17. A process for the endothermic dehydrogenation of an alkane stream comprising:
a) heating the alkane stream to produce a heated alkane stream;
b) contacting the heated alkane stream with a back-mixed fluidized bed of heated catalyst in a single reactor stage;
c) withdrawing deactivated catalyst from the back-mixed fluidized bed of heated catalyst;
d) heating the deactivated catalyst in a fluidized bed regenerator to regenerate the deactivated catalyst and produce hot regenerated catalyst; and
e) recycling the hot regenerated catalyst to the back-mixed fluidized bed of heated catalyst at a rate sufficient to maintain the back-mixed fluidized bed at substantially isothermal conditions.
18. The process according to claim 17 in which the endothernic dehydrogenation of the alkane stream requires a heat of reaction and the hot regenerated catalyst provides the heat of reaction for dehydrogenating the alkane stream.
19. The process according to claim 17 in which the endothermic dehydrogenation of the alkane stream takes place at a reaction temperature and the alkane stream is heated to approximately the reaction temperature in step (a).
20. The process according to claim 17 in which the endothermic dehydrogenation of the alkane stream takes place at a reaction temperature substantially in the range 500\xb0 to 700\xb0 C. and the hot regenerated catalyst is recycled to the back-mixed fluidized bed of heated catalyst at a rate sufficient to maintain the back-mixed fluidized bed at substantially the reaction temperature.