To identify the file system type, see Determining a File System's Type.
Disk-based file systems are stored on physical media such as hard disks and DVDs. Disk-based file systems can be written in different formats. The available formats are described in the following table.
Each type of disk-based file system is customarily associated with a particular media device, as follows:
ZFS or UFS with hard disk
HSFS with CD-ROM
PCFS with USB diskette
UDF with DVD
SAM-QFS with a hard disk or tape
PxFS with a hard disk - For a cluster file system to be highly available, the underlying disk storage must be connected to more than one Oracle Solaris host. Therefore, a local file system (a file system that is stored on a host's local disk) that is made into a cluster file system is not highly available. For more information, see Cluster File Systems in Oracle Solaris Cluster Concepts Guide .
However, these associations are not restrictive. For example, DVDs can have ZFS or UFS file systems created on them.
For information about creating a UDFS file system on removable media, see How to Create a File System on Removable Media in Managing Devices in Oracle Solaris 11.2 .
The UDF file system is provided as dynamically loadable 32-bit and 64-bit modules, with system administration utilities for creating, mounting, and checking the file system on both SPARC and x86 platforms. The Oracle Solaris UDF file system works with supported ATAPI and SCSI DVD drives, CD-ROM devices, and disk drives. In addition, the Oracle Solaris UDF file system is fully compliant with the UDF 1.50 specification.
The UDF file system provides the following features:
Ability to access the industry-standard CD-ROM and DVD-ROM media when they contain a UDF file system
Flexibility in exchanging information across platforms and operating systems
The following features are not included in the UDF file system:
Support for write-once media, (CD-RW), with either the sequential disk-at-once recording and incremental recording
The UDF file system requires the following:
Supported SPARC or x86 platform
Supported CD-ROM or DVD-ROM device
The Oracle Solaris UDF file system implementation provides the following:
Support for industry-standard read/write UDF version 1.50
Fully internationalized file system utilities
With the NFS service, you can provide distributed resources (files or directories) by sharing them from a server and mounting them on individual clients. For more information, see The NFS Environment.
With the Oracle SMB service, you can provide distributed resources (files or directories) to Windows and Mac OS systems by sharing them from a server and mounting them on individual clients. For more information, see The Oracle Solaris SMB Service.
Virtual file systems are memory-based file systems that provide access to special kernel information and facilities. Most virtual file systems do not use file system disk space. Also, some virtual file systems, such as the temporary file system (TMPFS), use the swap space on a disk.
The temporary file system (TMPFS) uses local memory for file system reads and writes. Using TMPFS can improve system performance by saving the cost of reading and writing temporary files to a local disk or across the network. For example, temporary files are created when you compile a program. The OS generates a much disk activity or network activity while manipulating these files. Using TMPFS to hold these temporary files can significantly speed up their creation, manipulation, and deletion.
Files in TMPFS file systems are not permanent. These files are deleted when the file system is unmounted and when the system is shut down or rebooted.
TMPFS is the default file system type for the /tmp directory in the Oracle Solaris OS. You can copy or move files into or out of the /tmp directory, just as you would in a ZFS or UFS file system. The TMPFS file system uses swap space as a temporary backing store.
If a system with a TMPFS file system does not have adequate swap space, two problems can occur:
The TMPFS file system can run out of space, just as regular file systems do.
Because TMPFS allocates swap space to save file data (if necessary), some programs might not execute because of insufficient swap space.
The loopback file system (LOFS) lets you create a new virtual file system so that you can access files by using an alternative path name. For example, you can create a loopback mount of the root (/) directory on /tmp/newroot. This loopback mounts make the entire file system hierarchy appear as if it is duplicated under /tmp/newroot, including any file systems mounted from NFS servers. All files will be accessible either with a path name starting from root (/), or with a path name that starts from /tmp/newroot.
For information on how to create LOFS file systems, see Chapter 2, Creating and Mounting File Systems.
The process file system (PROCFS) resides in memory and contains a list of active processes, by process number, in the /proc directory. Information in the /proc directory is used by commands such as ps. Debuggers and other development tools can also access the address space of the processes by using file system calls.
Caution - Do not delete files in the /proc directory. The deletion of processes from the /proc directory does not kill them. /proc files do not use disk space, so there is no reason to delete files from this directory.
The /proc directory does not require administration.
These additional types of virtual file systems are listed for your information. They do not require administration.
The ZFS, UFS, NFS, and TMPFS file systems have been enhanced to include extended file attributes. Extended file attributes enable application developers to associate specific attributes to a file. For example, a developer of an application used to manage a windowing system might choose to associate a display icon with a file. Extended file attributes are logically represented as files within a hidden directory that is associated with the target file.
You can use the runat command to add attributes and execute shell commands in the extended attribute namespace. This namespace is a hidden attribute directory that is associated with the specified file.
To use the runat command to add attributes to a file, you first have to create the attributes file.
$ runat filea cp /tmp/attrdata attr.1
Then, use the runat command to list the attributes of the file.
$ runat filea ls -l
For more information, see runat (1) .
Many Oracle Solaris file system commands have been modified to support file system attributes by providing an attribute-aware option. Use this option to query, copy, or find file attributes. For more information, see the specific man page for each file system command.
The Oracle Solaris OS uses some disk slices for temporary storage rather than for file systems. These slices are called swap slices, or swap space. Swap space is used for virtual memory storage areas when the system does not have enough physical memory to handle current processes.
Since many applications rely on swap space, you should know how to plan for, monitor, and add more swap space, when needed. For an overview about swap space and instructions for adding swap space, see Chapter 3, Configuring Additional Swap Space.