The user domain (domU) is a virtualized database node.

Each user domain has 4 virtual disks at the management domain (dom0) level. This can be seen from /EXAVMIMAGES/GuestImages/user_domain_name/vm.cfg. These 4 virtual disks are in turn soft linked to 4 files under /EXAVMIMAGES/GuestImages/user_domain_name, which are the real disk image files as described below:

• /dev/xvda, for the system image file System.img
• /dev/xvdb, for the Oracle Grid Infrastructure image file, for example, grid12.1.0.2.2.img. This virtual disk is 50 GB in size and is mounted as /u01/app/version/grid.
• /dev/xvdc, for the Oracle Database image file, for example, db12.1.0.2.2-3.img. This virtual disk is 50 GB in size and is mounted as /u01/app/oracle/product/version/dbhome_1.
• /dev/xvdd, for the pv1_vgexadb.img image file

The System.img (/dev/xvda) disk has 2 partitions created on pre-grub2 images and 3 partitions on grub2 images.

• Pre-Grub2 image
  • Partition 1 — The boot partition (/boot) for the user domain (512 MB), represented as xvda1 in the user domain.
  • Partition 2 — Where the bios-grub is stored (24.5 GB), represented as xvda2 in the user domain.
• Grub2 image
  • Partition 1 — The boot partition (/boot) for the user domain (512 MB), represented as xvda1 in the user domain.
  • Partition 2 — The EFI boot partition on Oracle Exadata Database MachineX7 and later systems
  • Partition 3 — Where the bios-grub is stored (24.5 GB), represented as xvda3 in the user domain.

The pv1_vgexadb.img (/dev/xvdd) disk has 1 partition. The disk partition /dev/xvdd1 is 62 GB in size.

For pre-grub2 images, 2 physical volumes (PVs) are laid on top of the xvda2 and xvdd1 partitions. On grub2 images, 2 physical volumes (PVs) are laid on top of the xvda3 and xvdd1 partitions. A volume group (VgExaDb) of size 86.49G is laid on top of these physical volumes. This volume group contains the following logical volumes (LVMs):

• /dev/VGExaDb/LVDbSys1 (24 GB) — used for the root file system /. This LVM is confined to the xvda2 partition (for pre-grub2 images) or the xvda3 partition (for grub2 images).
• /dev/VGExaDb/LVDbSys2 (24 GB) — used for dbnodeupdate backups.
• /dev/VGExaDb/LVDbOra1 (24 GB) — used for the /u01 file system which holds the diagnostic_dest area.
• /dev/VGExaDb/LVDbSwap1 (16 GB) — used for swap
• /dev/VGExaDb/LVDbDoNotRemoveOrUse (1 GB) — a reserved LVM used by dbnodeupdate
• /dev/VGExaDb/LVDbVdnodenamedgname (128 MB) — for the quorum disks.

All but the first and last LVMs in the list above are contained in the xvdd1 partition.