that array contains a full copy of the filesystem, and GRUB can boot from that.
Therefore, if you're using RAID levels other than RAID 1, or if you're using LVM, you must create a separate boot filesystem. The mount point for this filesystem is
If you are not using RAID, create a small partition to hold the boot filesystem. In Disk Druid click the New button, which will bring up the Add Partition dialog shown in Figure 10-11 . Enter a mount point of
Figure 10-11. Add Partition window
If you are using RAID, follow the steps in the next section to create a boot partition.
10.2.1.2. Creating RAID devices
Table 10-1 shows RAID level recommendations for various numbers of disk drives. ( Table 6-3 describes the RAID levels supported by Fedora.)
Table 10-1. RAID recommendations based on the number of same-sized disk drives
| # of disk drives | Possible RAID levels | Recoverable failure | Notes |
|---|---|---|---|
| 1 | Cannot use RAID | None | |
| 2 | RAID 0 | None | Improves performance but also increases the risk of data loss. It provides storage capacity equal to two drives. |
| RAID 1 | 1 drive | Provides storage capacity equal to one drive. | |
| 3 | RAID 5 | 1 drive | Provides storage capacity equal to two drives. |
| 4 or more | RAID 5 with no hot spares | 1 drive | Provides storage capacity equal to the number of drives minus one. |
| RAID 5 with hot spare(s) | 1 drive at a time to a sequential maximum failure of 1 + the number of hot spares | Provides storage capacity equal to the number of drives minus the number of hot spares minus one. | |
| RAID 6 with no hot spares | 2 drives | Provides storage capacity equal to the number of drives minus two. | |
| 5 or more | RAID 6 with hot spare(s) | 2 drives at a time to a maximum of 2 + the number of hot spares | Provides storage capacity equal to the number of drives minus the number of hot spares minus two. |
To create a RAID array (device), you must first create the partitions that will make up the elements of the array. Start by creating a RAID 1 boot partition of about 100 MB on each drive. Although it's tempting to create a giant RAID partition to use the rest of the space, I recommend that you divide the space on each drive into five partitions of roughly equal size. For example, if you are using 120 GB disk drives, create five partitions of 24 GB; if you are using 10 GB drives, create five partitions of 2 GB. Combine these partitions into five RAID arrays, each incorporating one partition from each drive, and then combine those five RAID arrays into a single volume group. The advantage to this approach is that it enables you to migrate to a different RAID level as long as a minimum of 20 percent of the VG space is free (see Lab 6.1, 'Using Logical Volume Management ').
To create a partition to serve as a RAID array element, click the New button in Disk Druid's main window. The Add Partition dialog will appear, as in Figure 10-12 .
Figure 10-12. Adding a RAID partition
Another way to create a RAID partition is by clicking on the RAID button; the dialog in Figure 10-13 will appear, asking what you want to do next. Select the option 'Create a software RAID partition' and click OK.
For the File System Type, select 'software RAID.' Deselect all of the Allowable Drives checkboxes except one to indicate the drive on which you wish to create the partition. Enter the Size in megabytes, and select 'Fixed size.' Click OK to proceed.
Repeat this process to create partitions for the other elements of the RAID array on other drives. For
