These gaps contain metadata for partition information. For the logical partitions ( hda5 through hda9), there are also gaps between the end of one logical partition and the start of the next logical partition. Notice that there is a gap between start of the extended partition ( hda3) and the start of the first logical partition ( hda5). The following example fdisk output shows the original partition table for a system's root disk:ĭisk /dev/hda: 255 heads, 63 sectors, 2431 cylinders These subdisks are deleted automatically when a root disk is unencapsulated. METADATA subdisks are created during root disk encapsulation to protect partitioning information. Pl swapvol-01 swapvol ENABLED 4112640 - ACTIVEĪllocation of METADATA Subdisks During Root Disk Encapsulation Pl mirswapvol-01 swapvol ENABLED 4112640 - ACTIVE Pl rootvol-01 rootvol ENABLED 12337857 - ACTIVE Pl mirrootvol-01 rootvol ENABLED 12337857 - ACTIVE TY NAME ASSOC KSTATE LENGTH PLOFFS STATE. The following is example output from the vxprint command after the root disk has been encapsulated and its mirror has been created (the TUTIL0 and PUTIL0 fields and the subdisk records are omitted for clarity): The operations to set up the root disk mirror take some time to complete. For example, to mirror the root disk, sda, onto disk sdb, and give this the disk name rootmir, you would use the following command: The alternate root disk is configured to allow the system to be booted from it in the event that the primary root disk fails. Mirror_da_name is the disk access name of the disk that is to mirror the root disk, and mirror_dm_name is the disk media name that you want to assign to the mirror disk. # /etc/vx/bin/vxrootmir mirror_da_name mirror_dm_name The disk that is used for the root mirror must not be under Volume Manager control already.Īlternatively, to mirror all file systems on the root disk, run the following command: (These automatically invoke the vxrootmir command if the mirroring operation is performed on the root disk.) Select menu item 6 (Mirror Volumes on a Disk) from the vxdiskadm main menu, or use the VEA to create a mirror of the root disk. Choose a disk that is at least as large as the existing root disk, whose geometry is seen by Linux to be the same as the existing root disk, and which is not already in use by VxVM or any other subsystem (such as a mounted partition or swap area).To mirror the root disk onto another disk after encapsulation This can prevent your system from booting correctly. Warning: When modifying the /etc/fstab and the boot loader configuration files, take care not to corrupt the entries that have been added by VxVM. The contents of the original /etc/fstab and boot loader configuration files are saved in the files /etc/fstab.b4vxvm, /boot/grub/4vxvm or /etc/4vxvm for GRUB, and /etc/4vxvm for LILO. A special entry, vxvm_root, is added to the boot loader configuration file to allow the system to boot from an encapsulated root disk.Entries are changed in /etc/fstab for the rootvol, swapvol and other volumes on the encapsulated root disk.You must reboot the system for the changes to take effect.īoth the vxdiskadm and vxencap procedures for encapsulating the root disk also update the /etc/fstab file and the boot loader configuration file ( /boot/grub/menu.lst or /etc/nf (as appropriate for the platform) for GRUB or /etc/nf for LILO): The name bootdg is reserved as an alias for the name of the boot disk group, and cannot be used. If no boot disk group currently exists, one is created with the specified name. Where diskgroup must be the name of the current boot disk group. # /etc/vx/bin/vxencap -c -g diskgroup rootdisk=sda You can also use the vxencap command, as shown in this example where the root disk is sda: You can use menu item 2 of the vxdiskadm command to encapsulate the root disk. See "Restrictions on using rootability with Linux" on page 109. See the Veritas Volume Manager Troubleshooting Guide. You may need this information should you subsequently need to recreate the original root disk. For more information, see the appropriate manual pages. Use the fdisk or sfdisk commands to obtain a printout of the root disk partition table before you encapsulate the root disk. This makes it possible to recover from failure of your root disk by replacing it with one of its mirrors. VxVM allows you to mirror the root volume and other areas needed for booting onto another disk. Encapsulating and mirroring the root disk
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