Expert Oracle Exadata - Parent Directory

CHAPTER 9 RECOVERING EXADATAExternal USB DriveIn addition to the built-in CELLBOOT USB flash drive, Exadata also provides a way to create your ownexternal bootable recovery image using a common 1–8GB USB flash drive you can buy at the localelectronics store. Exadata will create the rescue image on the first external USB drive it finds, so beforeyou create this recovery image you must remove all other external USB drives from the system or thescript will throw a warning and exit.Recall that Exadata storage cells maintain two versions of the operating system and cell software:active and inactive. These are managed as two separate sets of disk partitions for the / and /opt/oraclefile systems as can be confirmed using the imageinfo command, as follows:> imageinfo | grep deviceActive system partition on device: /dev/md6Active software partition on device: /dev/md8Inactive system partition on device: /dev/md5Inactive software partition on device: /dev/md7The imageinfo command shows the current (Active), and previous (Inactive) system volumes on thestorage cell. Using the df command we can see that we are indeed currently using the Active partitions(/dev/md6 and /dev/md8) identified in the output from the imageinfo command.> df | egrep 'Filesystem|md6|md8'Filesystem 1K-blocks Used Available Use% Mounted on/dev/md6 10317752 6632836 3160804 68% //dev/md8 2063440 654956 1303668 34% /opt/oracleBy default, the make_cellboot_usb command will create a rescue image of your active configuration(the one you are currently running). The –inactive option allows you to create a rescue image from theprevious configuration. The inactive partitions are the system volumes that were active when the lastpatch was installed.The make_cellboot_usb command is used to create a bootable rescue image. To create an externalrescue image, all you have to do is plug a USB flash drive into one of the USB ports on the front panel ofthe storage cell and run the make_cellboot_usb command.■ Caution: The rescue image will be created on the first external USB drive found on the system. Before creatingan external rescue image, remove all other external USB drives from the system.For example, the following listing shows the process of creating an external USB rescue image. Theoutput from the make_cellboot_usb script is fairly lengthy, a little over 100 lines, so we won’t show all ofit here. Some of the output excluded from the following listing includes output from the fdisk commandthat is used to create partitions on the USB drive, formatting of the file systems, and the many files thatare copied to create the bootable rescue disk.[enkcel01:root] /opt/oracle.SupportTools> ./make_cellboot_usb...Candidate for the Oracle Exadata Cell start up boot device: /dev/sdad289