Method for waking up a plurality of hibernated mass storage devices

1. Field of the Invention

The present invention relates to a method for waking up a plurality of hibernated mass storage devices, and more particularly, to a method for waking up a plurality of hibernated mass storage devices group by group.

2. Description of the Prior Art

As related technology keeps improving, mass storage devices possess more space for storing more data. In order to provide larger space at lower cost, a storage system may comprise an array of hard disks, such as Redundant Array of Independent Disks (RAID). Generally, the hard disks of the storage system consume more than 50% of total power of the storage system. In order to decrease power consumption, when the storage system is in an idle state, the hard disks of the storage system are set to a hibernation mode to stop operation of the hard disks. However, when the storage system is trying to wake up the hibernated hard disks to access data stored in the hard disks, the hibernated hard disks need more power to be woken up immediately, so that the power consumption of the storage system increases sharply. The power consumption of the storage system during the wake up process is much larger than the power consumption of the storage system during normal operation.

The storage system of the prior art is not able to wake up the hibernated hard disks with lower power consumption. Besides, a power supply with maximum power much larger than the power consumption of the storage system during normal operation is needed for the storage system. Therefore, the storage system of the prior art is not power efficient.

The present invention provides a method for waking up a plurality of hibernated mass storage devices. The method comprises receiving a first command from a control circuit for accessing data stored in a plurality of hibernated mass storage devices; dividing the plurality of hibernated mass storage devices into a plurality of mass storage groups; waking up a first mass storage group of the plurality of mass storage groups; and notifying the control circuit to stop sending commands to the remaining hibernated mass storage devices in a period of time.

These and other objectives of the present invention will no doubt become obvious to those of ordinary skill in the art after reading the following detailed description of the preferred embodiment that is illustrated in the various figures and drawings.

FIG. 1 is a diagram showing a storage system of the present invention.

FIG. 2 to FIG. 5 are diagrams showing the storage system waking up the plurality of hibernated hard disks.

FIG. 6 is a flowchart showing a method of the present invention for waking up a plurality of hibernated mass storage devices.

Please refer to FIG. 1 , which is a diagram showing a storage system 100 of the present invention. The storage system 100 of the present invention comprises a control circuit 110 , an array of hard disks 120 , a wake up module 130 , and a power supply 140 . The control circuit 110 is for controlling operation of the array of hard disks 120 . The power supply 140 is electrically connected to the array of hard disks 120 for providing power to the array of hard disks 120 . The wake up module 130 is for controlling a wake up process of the array of hard disks 120 according to power consumption of the hard disks HD 1 -HD 10 and power performance of the power supply 140 . The wake up module 130 can be in a form of hardware, firmware, software, or any combination of the above.

Please refer to FIG. 2 to FIG. 5 , and refer to FIG. 1 as well. FIG. 2 to FIG. 5 are diagrams showing the storage system 100 waking up the plurality of hibernated hard disks HD 1 -HD 10 . When the storage system 100 is in an idle state, the hard disks HD 1 -HD 10 of the storage system 100 are set to a hibernation mode to stop operation of the hard disks HD 1 -HD 10 , such that power consumption of the storage system 100 is decreased. In order to wake up the hibernated hard disks HD 1 -HD 10 to access data stored in the hard disks HD 1 -HD 10 , the control circuit 110 generates a command to wake up the hibernated hard disks HD 1 -HD 10 . After the wake up module 130 receives the command, the wake up module 130 divides the plurality of hibernated hard disks HD 1 -HD 10 into a plurality of mass storage groups according to power consumption of the hard disks HD 1 -HD 10 and power performance of the power supply 140 . For example, assuming a maximum power of the power supply 140 is 200 Watts, a transient power limit of the power supply 140 is 100 Watts, the power consumption of each hard disk HD 1 -HD 10 in the hibernation mode is 2 Watts, the power consumption of other remaining components is 10 Watts, a transient power to wake up each hibernated hard disk HD 1 -HD 10 from the hibernation mode is 28 Watts (from 2 Watts to 30 Watts), and the power consumption of each hard disk HD 1 -HD 10 in operation is 15 Watts, then the wake up module 130 divides the plurality of hibernated hard disks HD 1 -HD 10 into four mass storage groups G 1 -G 4 , where the first mass storage group G 1 comprises three hibernated hard disks HD 1 -HD 3 , the second mass storage group G 2 comprises three hibernated hard disks HD 4 -HD 6 , the third mass storage group G 3 comprises two hibernated hard disks HD 7 and HD 8 , and the fourth mass storage group comprises two hibernated hard disks HD 9 and HD 10 .

As shown in FIG. 2 , the wake up module 130 first wakes up the first mass storage group G 1 , and the second to fourth mass storage groups G 2 -G 4 are still in the hibernation mode. The transient power to wake up the first mass storage group G 1 is 84 Watts, which is lower than the transient power limit of the power supply 130 . The total power consumption of the storage system 100 is 116 Watts, which is lower than the maximum power of the power supply 140 . The woken up hard disks HD 1 -HD 3 in the first mass storage group G 1 will then respond to the control circuit 110 for data access, and the hibernated hard disks HD 4 -HD 10 in the mass storage groups G 2 -G 4 will not respond to the control circuit 110 . If the control circuit 110 does not receive any response from the hibernated hard disks HD 4 -HD 10 , the control circuit 110 may assume the hibernated hard disks HD 4 -HD 10 are in an error state. In order to prevent such a situation, the wake up module 130 generates a notice to notify the control circuit 110 that the remaining hibernated hard disks HD 4 -HD 10 are in a busy state, such that the control circuit 110 will stop sending commands to the remaining hibernated hard disks HD 4 -HD 10 in a period of time. The wake up module 130 also can generate other kinds of notice (such as a reject notice) to the control circuit 110 to request the control circuit 110 to stop sending commands to the remaining hibernated hard disks HD 4 -HD 10 in a period of time. When there are still some hard disks in the hibernation mode, the wake up module 130 will keep generating a notice corresponding to the command transmitted from the control circuit 110 for accessing data stored in the hibernated hard disks, such that the control circuit 110 will stop sending commands to the remaining hibernated hard disks in a period of time. The notice or command transmitted between the control circuit 110 and the wake up module 130 can be a hardware command, a software command, or any other type of command.

As shown in FIG. 3 , after the first mass storage group G 1 is woken up, the wake up module 130 then wakes up the second mass storage group G 2 , and the third and fourth mass storage groups G 3 , G 4 are still in the hibernation mode. The transient power to wake up the second mass storage group G 2 is 84 Watts, which is lower than the transient power limit of the power supply 140 . The total power consumption of the storage system 100 is 153 Watts, which is lower than the maximum power of the power supply 140 . Similarly, the wake up module 130 will generate the notice corresponding to the command transmitted from the control circuit 110 for accessing data stored in the hibernated hard disks HD 7 -HD 10 , such that the control circuit 110 will stop sending commands to the remaining hibernated hard disks HD 7 -HD 10 in a period of time.

As shown in FIG. 4 , after the first and the second mass storage groups G 1 , G 2 are woken up, the wake up module 130 then wakes up the third mass storage group G 3 , and the fourth mass storage group G 4 is still in the hibernation mode. The transient power to wake up the third mass storage group G 3 is 56 Watts, which is lower than the transient power limit of the power supply 140 . The total power consumption of the storage system 100 is 164 Watts, which is lower than the maximum power of the power supply 140 . Similarly, the wake up module 130 will generate the notice corresponding to the command transmitted from the control circuit 110 for accessing data stored in the hibernated hard disks HD 9 -HD 10 , such that the control circuit 110 will stop sending commands to the remaining hibernated hard disks HD 9 -HD 10 in a period of time.

As shown in FIG. 5 , after the first to the third mass storage groups G 1 -G 3 are woken up, the wake up module 130 then wakes up the fourth mass storage group G 4 . The transient power to wake up the fourth mass storage group G 4 is 56 Watts, which is lower than the transient power limit of the power supply 140 . The total power consumption of the storage system 100 is 190 Watts, which is slightly smaller than the maximum power of the power supply 140 . After all the hard disks HD 1 -HD 10 are woken up, the total power consumption of the storage system 100 is lowered down to 160 Watts, which is lower than the maximum power of the power supply 140 . And the control circuit 110 can then directly control all the hard disks HD 1 -HD 10 .

According to the above arrangement, the quantity of hard disks in each mass storage group is determined according to power consumption of the hard disks HD 1 -HD 10 and power performance of the power supply 140 . Compared to waking up all the hard disks at the same time, where the transient power limit and the maximum power of a power supply must be more than 300 Watts, the method of the present invention can utilize a power supply with smaller transient power limit and smaller maximum power.

The quantity of hard disks in each mass storage group can be predetermined according to the power consumption of the hard disks HD 1 -HD 10 and the power performance of the power supply 140 , or the quantity of hard disks in each mass storage group can be dynamically determined according to the power consumption of the hard disks HD 1 -HD 10 and the power performance of the power supply 140 during the wake up process. When determining the quantity of hard disks in each mass storage group, the transient power to wake up the hibernated hard disks should not be over the transient power limit of the power supply 140 , and the total power of the storage system 100 should not be over the maximum power of the power supply 140 .

In addition, lengths of awake time intervals between each mass storage group G 1 -G 4 can be predetermined according to the power consumption of the hard disks HD 1 -HD 10 and the power performance of the power supply 140 , or the lengths of awake time intervals between each mass storage group G 1 -G 4 can be dynamically determined according to the power consumption of the hard disks HD 1 -HD 10 and the power performance of the power supply 140 during the wake up process. For example, an awake time interval between the first and second mass storage groups, an awake time interval between the second and third mass storage groups, and an awake time interval between the third and fourth mass storage groups can be determined as 3 seconds, 3 seconds, and 2 seconds respectively, where the first mass storage group needs 3 seconds to be woken up, the second mass storage group needs 3 seconds to be woken up, and the third mass storage group needs 2 seconds to be woken up.

Please refer to FIG. 6 . FIG. 6 is a flowchart showing a method of the present invention for waking up a plurality of hibernated hard disks. The flowchart of the method for waking up a plurality of hibernated hard disks comprises the following steps:

Step 610 : Receive a first command from a control circuit for accessing data stored in a plurality of hibernated hard disks;

Step 620 : Divide the plurality of hibernated hard disks into a plurality of mass storage groups;

Step 630 : Wake up a mass storage group of the plurality of mass storage groups;

Step 640 : Notify the control circuit to stop sending commands to the remaining hibernated hard disks in a period of time;

Step 650 : Determine whether all the mass storage groups are woken up; if yes, go to step 660 , if not, repeat steps 630 and 640 ; and

Basically, to achieve the same result, the steps of the flowchart 600 need not be in the exact order shown and need not be contiguous, that is, other steps can be intermediate.

In the above embodiment, the method of the present invention is utilized to wake up a plurality of hard disks, but in other embodiments, the method of the present invention can also be utilized to wake up other kinds of mass storage devices.

In contrast to the prior art, the present invention provides a method for waking up a plurality of hibernated mass storage devices group by group in order to decrease the power consumption during the wake up process. Besides, the method of the present invention can utilize a power supply with smaller transient power limit and smaller maximum power for the storage system. Therefore, the storage system utilizing the method of the present invention is more power-efficient.

Those skilled in the art will readily observe that numerous modifications and alterations of the device and method may be made while retaining the teachings of the invention. Accordingly, the above disclosure should be construed as limited only by the metes and bounds of the appended claims.