Sun Certified System Administrator for Solaris 10 Study Guide Exams 310-XXX & 310-XXX

Persistent data on a system is stored mostly on hard disks. The smallest storage unit on a disk is a sector, which typically has a capacity of 512 bytes. The disks have three kinds of names, which are automatically assigned to them when they are added to the system: the physical device name in the device information hierarchy, instance names used by the kernel, and the logical name used by the system administrator. SPARC-based systems use the same logical name scheme for disks with direct controllers (e.g., IDE) and disks with bus-oriented controllers (e.g., SCSI), whereas x86-based systems use different logical name schemes for these two kinds of disks.

Before a file system can reside on a disk, the disk must be divided into slices, and the process is called partitioning. Each file system resides on its own slice. You can perform partitioning by using the format command. Partition information is stored in the disk area called the disk label. Solaris 10 offers Extensible Firmware Interface (EM) labels to support disks with storage capacities of multiterabytes. If you add a new device to a Solaris 10 system admin, you do not need to reboot the system; just use the devfsadm command to have the system configure it and recognize it.

After a file system has been created on a disk slice, it must be mounted—that is, connected to the directory tree, in order to make it available for users. When the Solaris system is booted, it automatically mounts the file systems listed in the /etc/vfstab file with the mount on boot field set to yes. Once the system is booted, you can mount the new file systems and unmount them based on your needs by using the mount and umount commands, respectively.

Before users can use the file systems, they will be required to have accounts on the Solaris system. It will be one of your responsibilities as a system administrator to create and manage the user accounts. We explore this subject in the next chapter.

Inside the Exam

Comprehend

• Sector 0 on a VTOC disk is reserved for storing the label, and the first 34 sectors of an EFI disk are used for the label. Therefore, you cannot include these sectors in the slices.

• In Solaris 10, you do not need to reboot the system in order to recognize the newly added devices; just use the devfsadm command.

Look Out

• SPARC-based systems use the same logical device name scheme for disks with direct controllers and bus-oriented controllers, but x86-based systems use different schemes for these two kinds of disks.

• You cannot change the slice size after creating a file system on it without destroying it—that is, repartitioning it.

• In a VTOC disk, slice 2 is reserved for referring to the entire disk, whereas in an EFI disk, you can use it to meet your needs.

• You provide a raw device name (/dev/rdsk), not a blocked device name (dev/dsk), in the format command.

Memorize

• Each disk slice can hold only one file system, and each file system can reside only on one slice.

• Know all the options available in the format utility and what they do.

• The procedures to boot the system are stored in the boot block.

• In order to specify a no value for any field of an entry in the /etc/vfstab, type a hyphen (-), because a white space is not a valid value and may cause boot problems.

• You cannot edit the /etc/mnttab file.