Contents |
[edit] Introduction
This page contains instructions on how to manually partition disks using the CentOS installer. The instructions guide the user to create software RAID devices whenever possible.
[edit] One Disk
If you only have one disk, use the following instructions:
1. Click the 'New' button to create a new partiton. In the 'Add Partition' window that pops up, supply the following configuration. Click 'OK' when you are finished.
Mount point: / File system type: ext3 Allowable drives: (The only hard disk should already be selected) Size: 6000 Additional size options: Fixed size Force to be a primary partition: Yes Encrypt: No
2. Click the 'New' button to create a new partition. Use the following configuration. Click 'OK' when you are finished.
Mount point: Leave this blank File system type: swap Allowable drives: (The only hard disk should already be selected) Size: 2048 Force to be a primary partition: Yes Encrypt: No
3. Now, repeat the following until the free space on the disk is depleted: Click 'New' to add a new partition with the following configuration:
Mount point: /cacheN (increment N by one, starting from 0, for every cache partition created) File system type: ext3 Size: 1048576 (1TB expressed in megabytes) Additional size options: Fixed size OR if the free space is less than 1TB, select 'Fill to maximum allowable size' Force to be a primary partition: No Encrypt: No
[edit] Two Disks
If your disks are not of the same capacity, follow the first two steps here then for each disk, follow step three for the one disk case.
For two disks, we will create software RAID devices in "RAID1". This mode will maintain a mirror copy of the data on both disks so that in the event one disk fails there exists one full copy. Setting up software RAID devices is done in two phases. The first phase is creating partitions on the disks that will then be grouped in some way into software RAID devices. The grouping process is the second phase.
1. Do this once per disk: Click the 'RAID' button then select 'Create a software RAID partition'. In the 'Add Partition' window that pops up, supply the following configuration. Click 'OK' when you are finished.
File system type: software RAID (Should already be selected) Allowable drives: (Select only one disk at a time) Size: 6000 Additional size options: Fixed size Force to be a primary partition: Yes Encrypt: No
2. Do this once per disk: Click the 'RAID' button then select 'Create a software RAID partition'. In the 'Add Partition' window that pops up, supply the following configuration. Click 'OK' when you are finished.
File system type: software RAID (Should already be selected) Allowable drives: (Select only one disk at a time) Size: 2048 Additional size options: Fixed size Force to be a primary partition: Yes Encrypt: No
3. For each disk, repeat this as necessary to exhaust the free space: Click the 'RAID' button then select 'Create a software RAID partition'. In the 'Add Partition' window that pops up, supply the following configuration. Click 'OK' when you are finished.
File system type: software RAID Allowable drives: (Select only one disk at a time) Size: 1048576 (1TB expressed in megabytes) Additional size options: Fixed size OR if the free space is less than 1TB, select 'Fill to maximum allowable size' Force to be a primary partition: No Encrypt: No
4. Now, click the 'RAID' button again. Select 'Create a RAID device...' and click 'OK'. In the 'Make RAID Device' window that pops up, supply the following configuration. Press 'OK' when finished.
Mount Point: / File System Type: ext3 (Default) RAID Device: mdN (Accept the default) RAID Level: RAID1 RAID Members: (Select the devices ending in '1'; they should be 6000 MB a piece) Number of spares: 0 Encrypt: No
5. Click the 'RAID' button, select 'Create a RAID device...' and click 'OK'. In the 'Make RAID Device' window that pops up, supply the following configuration. Press 'OK' when finished.
Mount Point: (Leave blank) File System Type: swap RAID Device: mdN (Accept the default) RAID Level: RAID1 RAID Members: (Select the devices ending in '2'; they should each be the size of your RAM in megabytes) Number of spares: 0 Encrypt: No
6. Repeat as necessary until all software RAID partitions are grouped: Click the 'RAID' button, select 'Create a RAID device...' and click 'OK'. In the 'Make RAID Device' window that pops up, supply the following configuration. Press 'OK' when finished.
Mount Point: /cacheN (Increment N for each cache, starting from 0) File System Type: ext3 (Default) RAID Device: mdX (Accept the default) RAID Level: RAID1 RAID Members: (Select the devices ending in 'X'; they should each be 1048576MB) Number of spares: 0 Encrypt: No
[edit] Multiples Of Four Disks
If your disks are not of the same capacity, follow the first two steps in both phase one and two here then for each disk, follow step three for the one disk case.
We will create software RAID devices in "RAID1" and "RAID5". The former mode will maintain a mirror copy of the data on both disks so that in the event one disk fails there exists one full copy. The latter will use parity so that if a disk fails, the data can be reconstructed mathematically.
Setting up software RAID devices is done in two phases. The first phase is creating partitions on the disks that will then be grouped in some way into software RAID devices. The grouping process is the second phase.
Here, we will consider groups of four disks. The first group will hold the root, swap and cache partitions; the others will hold only cache partitions.
[edit] Phase One
1. Do this once per disk for the first two disks in the first group: Click the 'RAID' button then select 'Create a software RAID partition'. In the 'Add Partition' window that pops up, supply the following configuration. Click 'OK' when you are finished.
File system type: software RAID (Should already be selected) Allowable drives: (Select only one disk at a time) Size: 6000 Additional size options: Fixed size Force to be a primary partition: Yes Encrypt: No
2. Do this once per disk for the second pair of disks in the first group: Click the 'RAID' button then select 'Create a software RAID partition'. In the 'Add Partition' window that pops up, supply the following configuration. Click 'OK' when you are finished.
File system type: software RAID (Should already be selected) Allowable drives: (Select only one disk at a time) Size: 6000 (Not a typo -- we match the size of root partition) Additional size options: Fixed size Force to be a primary partition: Yes Encrypt: No
3. For each disk in all groups, repeat this as necessary to exhaust the free space: Click the 'RAID' button then select 'Create a software RAID partition'. In the 'Add Partition' window that pops up, supply the following configuration. Click 'OK' when you are finished.
File system type: software RAID Allowable drives: (Select only one disk at a time) Size: 1048576 (1TB expressed in megabytes) Additional size options: Fixed size OR if the free space is less than 1TB, select 'Fill to maximum allowable size' Force to be a primary partition: No Encrypt: No
[edit] Phase Two
4. Now, click the 'RAID' button again. Select 'Create a RAID device...' and click 'OK'. In the 'Make RAID Device' window that pops up, supply the following configuration. Press 'OK' when finished.
Mount Point: / File System Type: ext3 (Default) RAID Device: mdN (Accept the default) RAID Level: RAID1 RAID Members: (Select the devices from the first pair in the first group ending in '1'; they should be 6000 MB a piece) Number of spares: 0 Encrypt: No
5. Click the 'RAID' button, select 'Create a RAID device...' and click 'OK'. In the 'Make RAID Device' window that pops up, supply the following configuration. Press 'OK' when finished.
Mount Point: (Leave blank) File System Type: swap RAID Device: mdN (Accept the default) RAID Level: RAID1 RAID Members: (Select the devices from the second pair in the the first group ending in '1'; they should each be the size of your RAM in megabytes) Number of spares: 0 Encrypt: No
6. For each group, repeat as necessary until all software RAID partitions of the group are members of some software RAID device: Click the 'RAID' button, select 'Create a RAID device...' and click 'OK'. In the 'Make RAID Device' window that pops up, supply the following configuration. Press 'OK' when finished.
Mount Point: /cacheN (Increment N for each cache, starting from 0) File System Type: ext3 (Default) RAID Device: mdX (Accept the default) RAID Level: RAID5 RAID Members: (Select the devices of the same group ending in the same number; they should each be 1048576MB) Number of spares: 0 Encrypt: No
[edit] Multiples Of Three Disks
If your disks are not of the same capacity, follow the first two steps in both phase one and two here then for each disk, follow step three for the one disk case.
We will create software RAID devices in "RAID1" and "RAID5". The former mode will maintain a mirror copy of the data on both disks so that in the event one disk fails there exists one full copy. The latter will use parity so that if a disk fails, the data can be reconstructed mathematically.
Setting up software RAID devices is done in two phases. The first phase is creating partitions on the disks that will then be grouped into software RAID devices. The grouping process is the second phase.
Here, we will consider groups of three disks. The first group will hold the root, swap and cache partitions; the others will hold only cache partitions.
[edit] Phase One
1. Do this once per disk in the first group: Click the 'RAID' button then select 'Create a software RAID partition'. In the 'Add Partition' window that pops up, supply the following configuration. Click 'OK' when you are finished.
File system type: software RAID (Should already be selected) Allowable drives: (Select only one disk at a time) Size: 6000 Additional size options: Fixed size Force to be a primary partition: Yes Encrypt: No
2. Do this once per disk in the first group: Click the 'RAID' button then select 'Create a software RAID partition'. In the 'Add Partition' window that pops up, supply the following configuration. Click 'OK' when you are finished.
File system type: software RAID (Should already be selected) Allowable drives: (Select only one disk at a time) Size: 2048 Additional size options: Fixed size Force to be a primary partition: Yes Encrypt: No
3. For each disk in all groups, repeat this as necessary to exhaust the free space: Click the 'RAID' button then select 'Create a software RAID partition'. In the 'Add Partition' window that pops up, supply the following configuration. Click 'OK' when you are finished.
File system type: software RAID Allowable drives: (Select only one disk at a time) Size: 1048576 (1TB expressed in megabytes) Additional size options: Fixed size OR if the free space is less than 1TB, select 'Fill to maximum allowable size' Force to be a primary partition: No Encrypt: No
[edit] Phase Two
4. Now, click the 'RAID' button again. Select 'Create a RAID device...' and click 'OK'. In the 'Make RAID Device' window that pops up, supply the following configuration. Press 'OK' when finished.
Mount Point: / File System Type: ext3 (Default) RAID Device: mdN (Accept the default) RAID Level: RAID1 RAID Members: (Select the devices from the first group ending in '1'; they should be 6000 MB a piece) Number of spares: 0 Encrypt: No
5. Click the 'RAID' button, select 'Create a RAID device...' and click 'OK'. In the 'Make RAID Device' window that pops up, supply the following configuration. Press 'OK' when finished.
Mount Point: (Leave blank) File System Type: swap RAID Device: mdN (Accept the default) RAID Level: RAID1 RAID Members: (Select the devices from the first group ending in '2'; they should each be the size of your RAM in megabytes) Number of spares: 0 Encrypt: No
6. For each group, repeat as necessary until all software RAID partitions of the group are members of some software RAID device: Click the 'RAID' button, select 'Create a RAID device...' and click 'OK'. In the 'Make RAID Device' window that pops up, supply the following configuration. Press 'OK' when finished.
Mount Point: /cacheN (Increment N for each cache, starting from 0) File System Type: ext3 (Default) RAID Device: mdX (Accept the default) RAID Level: RAID5 RAID Members: (Select the devices of the same group ending in the same number; they should each be 1048576MB) Number of spares: 0 Encrypt: No
[edit] Other Disk Configurations
If the number of disks in your system can be expressed by 4m+3n for some positive integers m, n, use some combination of the three and four disk cases.
