Method, system and apparatus for scanning newly added disk drives and automatically updating RAID configuration and rebuilding RAID data

• US 6,952,794 B2
• Filed: 10/10/2002
• Issued: 10/04/2005
• Est. Priority Date: 10/10/2002
• Status: Expired due to Fees

• Current Assignee: Synology Incorporated
• Original Assignee: Synology Incorporated
• Inventors: Lu, Ching-hung
• Primary Examiner(s): KIM, HONG CHONG
• Application Number:
  US10/269,186
• Publication Number:
  US 20040073747A1
• Time in Patent Office: 1,090 Days
• Field of Search: 711/114, 711/162, 714/6, 714/7, 369/30.06, 719/325
• US Class Current: 714/6.22
• CPC Class Codes: G06F 11/1092 Rebuilding, e.g. when physically replacing a failing disk
• CPC Class Codes: G06F 11/1096 Parity calculation or recalculation after configuration or reconfiguration of the system
• CPC Class Codes: G06F 3/0605 by facilitating the interaction with a user or administrator
• CPC Class Codes: G06F 3/0632 by initialisation or re-initialisation of storage systems
• CPC Class Codes: G06F 3/0689 Disk arrays, e.g. RAID, JBOD

Abstract

The present invention pertains to a computer software implemented method, system, and apparatus for automatic updating disk drive configuration and rebuilding RAID data to assure proper data storage in a RAID configured system. The computer software implemented configuration mechanism utilizing CPU and memory of a computer system automatically generates a full configuration of the disk drives connected to system peripheral bus both at system initialization time and runtime. The configuration mechanism uses a computer-implemented procedure for scanning a newly added disk drive, detecting conflict to the existing configuration, resolving conflicts, finding a proper target referenced or ruined disk drive, replacing this target disk drive with the newly added disk drive, rebuilding the RAID data into the added disk drive, updating RAID configuration with the added disk drive, and presenting to the host operating system the current configuration information.

Claims

1. A computer implemented method for automatic updating and rebuilding the RAID configuration and configured data or disk drives in a RAID configured system, wherein said method employs computer implemented procedures to operate a RAID controller in a computer system having a CPU and memory for executing the procedures, disk drives, and a multiple system peripheral bus, comprising:

a) scanning all disk drive connected to multiple system peripheral bus of a computer system,

b) detecting by the RAID controller newly added disk drives connected to the system peripheral bus at initiation and runtime that at least one disk drive was added to the RAID controller,

c) distinguishing configured and un-configured disk drives in groups,

d) resolving conflict, where conflicted disk drives have the same configured location, by determining the most appropriate location among the conflicted disk drives such that when one disk drive is disconnected from a system and the other disk drive is connected into the system to replace the disconnected drive by choosing the disk drive with higher undate counts as a valid disk drive, and treating the other as an un-configured disk drive,

e) finding and selecting referenced disk drive in a RAID configuration when newly added disk drives are inserted into a configuration of the system peripheral bus by checking the referenced disk drives with the same physical location as the newly added disk drive if its size is large enough to rebuild RAID data to the newly added disk drive to start the rebuilding procedure, and if not, checking the other referenced disk drives, and finding one with enough space to rebuild RAID data to the newly added disk drives,

f) copying the configuration information of the disk drive group to the newly added disk drives.

g) rebuilding the RAID data into newly added disk drives according to RAID levels, and

h) presenting to the host operating system the disk drive configuration information.

2. The computer implemented method of claim 1, wherein the disk drive configuration information includes at least one identifier to identify a disk drive group, and each disk drive in the group has the same unique disk drive group identifier to distinguish them from disk drives in other groups.

3. The computer implemented method of claim 1, including recording the number of operative configuration times for each disk drive in the system as part of the configuration information with at least one update counter where the initial value of the update counter of a disk drive set at zero and increased by one each time a disk drive is involved in a configuration activity.

4. The computer implemented method of claim 1, wherein the disk drives contain volume layout structure as to each disk drive in a disk drive group, its configured location, and the size of sub-drives of each disk drive in the group.

5. The computer implemented method of claim 4, wherein the configuration information stored in a disk drive is in terms of how the logic units or volumes with RAID levels are formed in association with the disk drive group, where it belongs, and where a volume is formed by the sub-drives with the same RAID level that spans disk drives in the group.

6. The computer implemented method of claim 1, wherein the step of resolving conflict comprises:

choosing from among the conflicted disk drives the one having the largest value in its update counter to represent the value of all conflicted disk drives.

7. The computer implemented method of claim 6, including the steps of:

a. classifying all of the remaining conflicted disk drives not selected as unused, and

b. putting the remaining conflicted disk drives in an un-configured disk drive group for further processing.

8. The computer implemented method of claim 1, wherein after the referenced disk drive is found, including assigning the newly added disk drive as a target disk drive for copying configuration information of the referenced disk drive to the target disk drive and rebuilding RAID data into the target disk drive according RAID levels, and removing the referenced disk drive from its group.

9. The computer implemented method of claim 8, further comprising:

selecting, among the referenced disk drives located in a disk drive group, for each disk drive in the group having a same configuration location of the newly added disk drive, the one with enough space to rebuild RAID data to the newly added disk drive.

10. The computer implemented method of claim 1, wherein the rebuilding the configuration information comprises:

a) finding the sub-drive in sequential order;

b) checking if the found sub-drive belongs to a volume with a RAID level that can be rebuilt;

c) rebuilding the RAID data on the sub-drive, if it belongs to a volume that can be rebuilt;

otherwise

d) iteratively repeating steps a, b, and c until all sub-drives have been checked and rebuilt.

11. A computer implemented method for automatic updating and rebuilding the RAID data and configuration information of disk drives in a RAID configured system at system initialization time, wherein said system includes a CPU and memory with an operating system, disk drives with RAID data and configuration information, configuration information including at least one identifier to identify a disk drive group, and each disk drive in the group has the same unique disk drive group identifier to distinguish them from disk drives in other groups, volume layout structure as to each disk drive in a disk drive group, its configured location, and the size of sub-drives of each disk drive in the group, comprising the steps of:

a) scanning all disk drives connected to multiple system peripheral bus,

b) detecting newly added disk drives connected to the system peripheral bus when one disk drive is disconnected from a system and the other disk drive is connected into the system to replace the disconnected drive by choosing the disk drive with higher update counts as a valid disk drive, and treating the other as an un-configured disk drive,

c) recording the number of operative configuration times for each disk drive in the system as part of the configuration information, with the initial value of the update counter of a disk drive set at zero and increased by one each time a disk drive is involved in a configuration change,

d) resolving conflict, where conflicted disk drives have the same configured location by determining the most appropriate location among the conflicted disk drives by choosing from among the conflicted disk drives the one having the largest value in its update counter to represent the value of all conflicted disk drives via

i. classifying all of the remaining conflicted disk drives not selected as unused, and

ii. putting the remaining conflicted disk drives in an un-configured disk drive group for further process,

e) finding referenced disk drives when newly added disk drives are inserted into the system by checking the referenced disk drives with the same physical location as the newly added disk drive if its size is large enough to rebuild RAID data to the newly added disk drive to start the rebuilding procedure, and if not, checking the other referenced disk drives, and finding one with enough space to rebuild RAID data to the newly added disk drive, by

1) assigning the newly added disk drive as a target disk drive,

2) copying configuration information of the referenced disk drive to the target disk drive,

3) rebuilding RAID data into the target disk drive according RAID levels,

4) removing the referenced disk drive from its group,

5) rebuilding the RAID data into newly added disk drives via

i. finding the sub-drive in sequential order;

ii. checking if the found sub-drive belongs to a volume with a RAID level that can be rebuilt;

iii. rebuilding the data on the sub-drive, if it belongs to a volume that can be rebuilt;

otherwise

iv. iteratively repeating steps i, ii, and iii until all sub-drives have been checked and rebuilt, and

f) presenting to the host operating system the disk drive configuration information.

12. The computer implemented method of claim 11, wherein the volume layout structure stored in a disk drive is in terms of how the logic units or volumes with RAID levels are formed in association with the disk drive group, where it belongs, and where a volume is formed by the sub-drives with the same RAID level that spans disk drives in the group.

13. The computer implemented method according to claim 11, wherein step b, detecting the inactive disk drive, and step d, resolving conflict, further include:

a) analyzing configuration information of the system to obtain all referenced disk drives remaining in the system;

b) finding a referenced disk drive with space that its RAID data can be rebuilt into the newly added disk drive;

c) copying the configuration information of the disk drive group to the newly added disk drives,

d) rebuilding the RAID data into newly added disk drives according to RAID levels, and

e) iteratively repeating steps a through d until all of the referenced disk drives have been completely analyzed, and

f) returning to the start of the configuration procedure (step a of claim 11).

14. A computer implemented method for automatic updating and rebuilding the RAID data and configuration information of disk drives in a RAID configured computer system having a CPU with associated memory, disk drives and a multiple system peripheral bus at system run time, wherein the run-time configuration procedure for the system supports hot disk drive swapping, further comprises the steps of:

a) scanning all disk drives connected to the multiple system peripheral bus;

b) detecting a newly added disk drive and reading the configuration information stored in the detected disk drive when one disk drive is disconnected from a system and the other disk drive is connected into the system to replace the disconnected drive by choosing the disk drive with higher update counts as a valid disk drive, and treating the other as an un-configured disk drive;

c) checking whether the newly added disk drive is a valid disk drive

d) checking, in case when added disk drive is valid, if the added disk drive is conflict to an existing disk drive;

e) checking, in case when the added disk drive is conflicted to an existing disk drive, if the added disk drive belongs to an inactive disk drive group and the added disk drive contains a higher update count than that of the conflicted disk drive;

f) replacing, in the case when both the added disk drive and the conflicted disk drive belong to an inactive disk drive group but the added disk drive has newer configuration information, the conflicted disk drive by the newly added disk drive and taking the conflicted disk drive as a new disk drive for further processing;

or

g) integrating, in case the added disk drive is valid and has no conflict to any existing disk drive, the configuration information stored in the newly added disk drive to the system configuration;

h) finding, in the case when the newly added disk drive contains invalid configuration information or is conflicted to existing disk drive with lower update count than that of the conflicted disk drive, a suitable referenced disk drive for further processing by checking the referenced disk drives with the same physical location as the newly added disk drive if its size is large enough to rebuild RAID data to the newly added disk drive to start the rebuilding procedure, and if not, checking the other referenced disk drives, and finding one with enough space to rebuild RAID data to the newly added disk drive; and

i) iteratively repeating steps a through h during the run time.

15. A computer implemented method according to claim 14, wherein the step h, finding a suitable referenced disk drive, and step f, replacing the conflicted disk, further comprise:

a) finding a referenced disk drive with a same configuration location of the added disk drive and with space that its RAID data can be rebuilt into the newly added disk drive;

otherwise

b) finding a referenced disk drive, or a ruined disk drive with space that its RAID data can be rebuilt into the newly added disk drive;

c) copying the configuration information of the disk drive group to the newly added disk drives;

d) rebuilding the RAID data into newly added disk drives according to RAID levels, and

e) returning to the start of the procedure (step a of claim 14).

16. A computer software program embedded in a readable storage medium that directs a computer system connected with groups of disk drives to function in a specified manner for rebuilding a RAID configuration, comprising:

a. examining in sequence all sub-drives associated with a considered disk drives group;

b. finding the volumes and their associated RAID levels that can rebuild the RAID data by checking the referenced disk drives with the same physical position as the newly added disk drive if its large enough to rebuild RAID data to the newly added disk drive to start the rebuilding procedure, and if not, checking the other referenced disk drives, and finding one with enough space to rebuild RAID data to the newly added disk drive, and

c. rebuilding the RAID data based on the current configuration as well as based on the system-encountered situations such as conflict status of disk drives, size of disk drives, and update counts of disk drives when said system discovers a new added disk drive in run-time.

17. A computer software program embedded in a readable storage medium according to claim 16, wherein the RAID configurations associated with each volume consist of simple, span, RAID 0, RAID 1, RAID 5, and RAID 5 with spare, and each RAID level is provided with various protection modes and data storage capacity.

18. A computer software program embedded in a readable storage medium according to claim 16, further including:

generating a configuration for un-configured disk drives where the un-configured disk drive configuration includes one or more volumes, and each volume is configured in accordance with a particular RAID level such that the particular RAID level established for each volume after the generation of the configuration may be different than the generation configuration at the system boot-time.

19. An apparatus for automatically updating and rebuilding RAID configuration and RAID data of disk drives in a RAID configured system, comprising:

a. a host computer with CPU associated with an operating system, and memory,

b. a computer implemented software program utilizing the host computer and the CPU and operating system to behave a RAID controller,

c. a plurality of disk drives with configured locations and data,

d. at least one interface storage device operably associated with the CPU, and

e. a computer implemented software program stored on the interface storage device including;

i. means for identifying one or more un-configured disk drives from scanning the disk drives connected to the apparatus and reading their configuration information;

ii. means for arranging a proper configuration for the un-configured disk drives in accordance with various data types associated with logical disk drives or volumes with RAID levels; and

iii. means for configuring the un-configured disk drives with RAID levels based on the configuration information, location and size of sub-drives, and the value of update counts associated with each disk drive involved in the configuration.

20. An apparatus for automatically updating RAID configuration and rebuilding RAID data of disk drives according to claim 19, wherein the configuration information stored in a disk drive, whether it is a configured or un-configured, contains an unique disk drive group identifier, and including an update counter that keeps counting the number of operative actions associated with a disk drive, and volume layout structure indicating the configuration location, redundancy type, and size and location of sub-drives.

21. An apparatus for automatically updating RAID configuration and rebuilding RAID data of disk drives according to claim 19, wherein said means for arranging a proper configuration for the un-configured disk drives comprises insuring that:

a. the volume contains at least one normally functioning sub-drive when operating a RAID 1 level,

b. the volume has at most one abnormally functioned sub-drive in operating RAID 5 level,

c. the volume can have at most two abnormally functioning sub-drive in operating a RAID 5 with spare, and

d. the volume is kept intact in operating RAID 0, simple, and span.

22. An apparatus for automatically updating and rebuilding RAID configuration and configured data of disk drives according to claim 19, wherein the means for configuring the un-configured disk drives include:

a) means for identifying one or more valid configurations of disk drives having a configuration information stored thereupon;

b) means for finding a target disk drive to copy configuration information to a newly added disk drive;

c) means for rebuilding RAID data for the newly added disk drive; and

d) means for returning to the host operating system.