Requirements and Specifics of Restriping and Resizing
Requirements and specifics:
- Except RAID N+M.
- Only one RAID can be restriped at a time.
- To improve the performance of your system under workload, try to change the priority of restriping by changing the corresponding RAID parameter.
-
RAID state must not be one of the following:
- offline;
- need_restripe;
- restriping;
- degraded.
The RAID level can only be changed if the number of added drives is sufficient to fit all the data stored prior to the level change. The number of data drives in a group must not decrease. Note that for RAID levels 50, 60, and 70, the total number of drives must be a multiple of the group size. Please keep in mind that RAID 50 includes one syndrome drive per group, while RAID 60 has two and RAID 70 has three. These drives do not store information but are necessary for data recovery in case of loss.
Example: Adding 1 drive to a RAID 60 configuration with 14 disks and 2 groups is not feasible. The only possible configuration for 15 drives is 3 groups of 5 drives, with only 3 of them containing data. Performing this operation would result in a new RAID with fewer data drives, hence it cannot be done. However, it is possible to add 2 drives to create a new RAID configuration consisting of 2 groups, each containing 8 drives (2 syndrome and 6 data drives). This will increase the data storage space.
|
Current level |
New level |
Requirements |
Minimal number of drives you should add |
|---|---|---|---|
| RAID 0 | RAID 0 | 1 | |
|
RAID 1 |
1 |
||
|
RAID 10 |
RAID 0 contains only 1 drive. |
3 | |
| RAID 0 contains more than 1 drive | The number of drives to be added must be equal to the number of drives in the RAID 0. | ||
|
RAID 1 |
RAID 1 | 2 | |
|
RAID 10 |
2 | ||
|
RAID 5 |
2 | ||
|
RAID 10 |
RAID 10 | 4 | |
|
RAID 5 |
1 | ||
|
RAID 50 |
The number of RAID 50 disks must be a multiple of its group size. |
1 | |
|
RAID 5 |
RAID 5 | 1 | |
|
RAID 6 |
1 | ||
|
RAID 10 |
The number of RAID 10 disks must be an even number. The number of information disks in a group must not decrease. |
1 | |
|
RAID 50 |
The number of disks in RAID 50 must be at least 8. The number of disks in RAID 50 must be a multiple of its group size. The number of information disks in a group must not decrease. |
1 | |
|
RAID 6 |
RAID 6 | 1 | |
|
RAID 7.3 |
1 | ||
|
RAID 60 |
The number of disks in RAID 60 must be at least 8. The number of disks in RAID 60 must be a multiple of its group size.The number of information disks in a group must not decrease. |
1 | |
|
RAID 7.3 |
RAID 7.3 | 1 | |
|
RAID 70 |
The number of disks in RAID 70 must be at least 12. The number of disks in RAID 70 must be a multiple of its group size.The number of information disks in a group must not decrease. |
1 | |
|
RAID 50 |
RAID 50 | The number of disks in RAID 50 must be a
multiple of its group size. The number of information disks in a group must not decrease. |
1 |
|
RAID 60 |
The number of disks in RAID 60 must be at least 8. The number of disks in RAID 60 must be a multiple of its group size.The number of information disks in a group must not decrease. |
1 | |
|
RAID 60 |
RAID 60 | The number of disks in RAID 60 must be a
multiple of its group size. The number of information disks in a group must not decrease. |
1 |
|
RAID 70 |
The number of disks in RAID 70 must be at least 12. The number of disks in RAID 70 must be a multiple of its group size.The number of information disks in a group must not decrease. |
1 | |
| RAID 70 | RAID 70 | The number of disks in RAID 70 must be a multiple of its group
size. The number of information disks in a group must not decrease. |
1 |