# Method of calculating the available capacity before configuring RAID

21

1. You can view the available capacity during RAID array configuration.
2. You can also estimate the
? RAID 0: 100%
? RAID 1: 50%
? RAID 5: (N-1)/N
? RAID 6: (N-2)/N
? RAID 10: 50%
? RAID 1E: (N+1)/2N
? RAID 50: (N-M)/N
? RAID 60: (N-M*2)/N
N indicates the number of member hard disks in a RAID array. M indicates the number of sub-groups of a RAID array.
For example, if three 300 GB disks are used to create a RAID 5 array,
Disk usage rate: (3-1)/3 = 2/3
Available capacity of the RAID 5 array: 3 x 300 x 2/3 = 600 GB

###### Other related questions:
Method used to calculate RAID capacity
If the number of RAID member disks is N (excluding hot spare disks), available capacity of RAID 0 = N x disk capacity. Available capacity of RAID 1 = N x Disk capacity/Number of mirror groups Available capacity of RAID 3 = (N-1) x Disk capacity Available capacity of RAID 5 = (N-1) x Disk capacity Available capacity of RAID 6 = (N-2) x Disk capacity Available capacity of RAID 10 = N x Disk capacity/Number of mirror groups Available capacity of RAID 50 = (N-2) x Disk capacity

How to calculate the recording capacity
Recording data storage capacity = (Number of D1 recording channels x D1 bit rate x 3600 x 24 x Number of recording storage days + Number of 720p recording channels x 720p bit rate x 3600 x 24 x Number of recording storage days + Number of 1080p recording channels x 1080p bit rate x 3600 x 24 x Number of recording storage days)/8. In the case that the server storage capacity is fixed, if the number of recording channels is decreased and the recording bit rate is lowered, the number of recording storage days can be increased.

Adding a disk to a RAID array
You can add a disk to a RAID array as follows: 1. If the LSISAS2208 or LSISAS3108 RAID controller card is used, you can add a new disk to a RAID array online. For details about how to expand the virtual disk (VD) capacity online, see HUAWEI Server RAID Controller Card User Guide 09. 2. If the LSISAS2308 or LSISAS3008 RAID controller card is used, you cannot add a disk to a RAID array through online capacity expansion and cannot expand the VD capacity online. 3. If softRAID is used, you cannot add a disk to a RAID array online or expand the VD capacity online.

Calculation method of the SDH lower-order cross-connect capacity
Calculation method of the SDH lower-order cross-connect capacity: For example, if the queried VC-12 quantity of lower-order cross-connections is 2016, how do I calculate the lower-order cross-connect capacity? First, convert the VC-12 quantity to the VC-4 quantity. As one VC-4 contains 63 VC-12s, the VC-4 quantity is 32 (2016/63). Second, calculate the capacity. As the capacity of 64 VC-4s is 10 Gbit/s, the capacity of 32 VC-4s is 5 Gbit/s.

Method used to expand LUN capacity of OceanStor T Series
You can expand LUN capacity of OceanStor T Series as follows: Go to the Expand dialog box. In the ISM navigation tree, choose All Devices > SN_XX > Storage Resources > Block Storage Pools. (SN_XX indicates the target storage storage.) In the right function pane, select the RAID group you want to expand. Click Expand. The Expand dialog box is displayed. Expand a RAID group. In the Available Disks area, select the idle disks that you want to add to the RAID group. Note: To improve disk utilization, you are advised to select an idle disk of which the capacity is the same as that of a member disk in the RAID group. Click the idle disk and add the disk to the Selected Disks group box. Confirm the RAID group expansion. Click OK. The Warning dialog box is displayed. Read and confirm the information in the dialog box. Then select I have read the warning message carefully. Click OK. The Information dialog box is displayed, indicating that the operation is successful. Click OK to return to the Block Storage Pools page and complete RAID group expansion. Result After the RAID group is expanded, you can perform the following operations to check the total capacity of the RAID group after capacity expansion. On the Block Storage Pools page, select the RAID group after capacity expansion. Click the Details tab to view the total capacity of the RAID group after capacity expansion.

###### If you have more questions, you can seek help from following ways:
To iKnow To Live Chat