OCA /OCP Oracle Database 11g A ll-in-One Exam Guide- P82:There is an ever increasing demand for staff with IT industry certification. The benefits to employers are significant—they can be certain that staff have a certain level of competence—and the benefits to the individuals, in terms of demand for their services, are equally great. Many employers are now requiring technical staff to have certifications, and many IT purchasers will not buy from firms that do not have certified staff. | OCA OCP Oracle Database 11g All-in-One Exam Guide 766 The syntax of the md_backup command is md_backup -b location_of_backup -g dgname The location of the output file will default to a file named AMBR_BACKUP_ INTERMEDIATE_FILE in the directory from which ASMCMD was launched and if no disk groups are specified all mounted disk groups will be included. Exercise 20-5 Use the ASMCMD Utility In this exercise you will use the ASMCMD utility to investigate the files in the ASM disk group created in Exercise 20-4. 1. At an operating system prompt set your ORACLE_SID environment variable to the name of the ASM instance and launch the ASMCMD utility. On Windows set ORACLE_SID asm Or on Unix export ORACLE_SID asm asmcmd 2. Display details of your disk group. lsdg Note the difference between the values for Usable_file_MB space and Free_MB this is because the Type of the disk group is NORMAL which is mirrored. 3. Use the cd and ls commands to navigate to the directory and display the datafile shown in Step 3 of Exercise 20-4. cd DG1 orcl datafile ls -l 4. Create a backup of the ASM metadata relying on the defaults which will back up all mounted disk groups to a file in your current operating system directory. md_backup 5. Exit from the ASMCMD utility and inspect the generated file AMBR_BACKUP_ INTERMEDIATE_FILE with any editor. It will be readable but should not be edited. Observe the details of your disk group and disks. 6. Launch SQL Plus. Connect to the ASM instance as SYSASM and query views that describe your ASM files and disk groups. select from v asm_file select from v asm_diskgroup Note the correspondence with the results of Steps 2 and 3. Two-Minute Drill Describe Automatic Storage Management ASM ASM is a logical volume manager providing striping and optionally mirroring of Oracle database files. Chapter 20 Automatic Storage Management 767 The files that can be stored on ASM devices include datafiles tempfiles the controlfile online and archive redo log .
