This chapter describes how to mount and unmount file systems in the Solaris OS.This is a list of the step-by-step instructions in this chapter.How to Determine Which File Systems Are Mounted How to Add an Entry to the /etc/vfstab File How to Mount a File System (/etc/vfstab File) How to Mount a UFS File System (mount Command) How to Mount a UFS File System Without Large Files (mount Command) How to Mount an NFS File System (mount Command) How to Mount a PCFS (DOS) File System From a Hard Disk (mount Command) How to Verify a File System is Unmounted How to Stop All Processes Accessing a File System How to Unmount a File System After you create a file system, you need to make it available to the system so that you can use it. You make a file system available by mounting it, which attaches the file system to the system directory tree at the specified mount point. The root (/) file system is always mounted. The following table provides guidelines on mounting file systems based on how you use them.Mount Type Needed Suggested Mount Method Local or remote file systems that need to be mounted infrequently The mount command that you type manually from the command line. Local file systems that need to be mounted frequently The /etc/vfstab file, which mounts the file system automatically when the system is booted in multi user state. Remote file systems,, such as home directories, that need to be mounted frequently The /etc/vfstab file, which automatically mounts the file system when the system is booted in multiuser state. AutoFS, which automatically mounts the file system when you access it or unmounts the file system when you change to another directory. To enhance performance, you can also cache the remote file systems by using the CacheFS file system. You can mount removable media that contains a file system by inserting the media into the drive and running the volcheck command, if necessary. For more information on mounting removable media, see Chapter 1, Managing Removable Media (Overview).The following table lists the commands in the /usr/sbin directory that you use to mount and unmount file systems.Command Description Man Page mount Mounts file systems and remote resources. mount1M mountall Mounts all file systems that are specified in the /etc/vfstab file. The mountall command runs automatically when the system enters multiuser mode. mountall1M umount Unmounts file systems and remote resources. mount1M umountall Unmounts all file systems that are specified in the /etc/vfstab file. mountall1M Keep the following key points in mind when using the mount and mountall commands:The mount and mountall commands cannot mount a read/write file system that has known inconsistencies. If you receive an error message from the mount or mountall command, you might need to check the file system. See Chapter 21, Checking UFS File System Consistency (Tasks) for information on how to check the file system. The umount and umountall commands do not unmount a file system that is busy. A file system is considered busy if one of the following is true:A user is accessing a file or directory in the file system. A program has a file open in that file system. The file system is shared. You can use the remount option when remounting from read-only access to read-write access only. You cannot remount from read-write access to read-only access. The following table describes the commonly used options that you can specify with the mount o option. If you specify multiple options, separate them with commas (no spaces). For example, o ro,nosuid. For a complete list of mount options for each file system type, refer to the specific mount man page (for example, mount_ufs1M).mount Option File System Description bg | fg NFS If the first mount attempt fails, retries another mount in the background (bg) or in the foreground (fg). This option is safe for non critical vfstab entries. The default is fg. hard | soft NFS Specifies the procedure if the server does not respond. The soft option indicates that an error is returned. The hard option indicates that the retry request is continued until the server responds. The default is hard. intr | nointr NFS Specifies whether keyboard interrupts are delivered to a hung process while waiting for a response on a hard-mounted file system. The default is intr (interrupts allowed). largefiles | nolargefiles UFS Enables you to create files larger than 2 Gbytes. The largefiles option means that a file system mounted with this option might contain files larger than 2 Gbytes. If the nolargefiles option is specified, the file system cannot be mounted on a system that is running Solaris 2.6 or compatible versions. The default is largefiles. logging | nologging UFS Enables or disables logging for the file system. UFS logging is the process of storing transactions (changes that comprise a complete UFS operation) into a log before the transactions are applied to the UFS file system. Logging helps prevent UFS file systems from becoming inconsistent, which means fsck can be bypassed. Bypassing fsck reduces the time to reboot a system if it crashes, or after a system is shut down uncleanly.The log is allocated from free blocks on the file system, and is sized at about 1 Mbyte per 1 Gbyte of file system, up to a maximum of 64 Mbytes. The default is logging. atime | noatime UFS Suppresses access time updates on files, except when they coincide with updates to the time of the last file status change or the time of the last file modification. For more information, see stat2. This option reduces disk activity on file systems where access times are unimportant (for example, a Usenet news spool). The default is normal access time (atime) recording. remount All Changes the mount options associated with an already-mounted file system. This option can generally be used with any option except ro. However, what can be changed with this option depends on the file system type. retry=n NFS Retries the mount operation when it fails. n is the number of times to retry. ro | rw CacheFS, NFS, PCFS, UFS, HSFS Specifies read/write (rw) or read-only (ro). If you do not specify this option, the default is rw. The default option for HSFS is ro. suid | nosuid CacheFS, HSFS, NFS, UFS Allows or disallows setuid execution. The default is to allow setuid execution. An entry in the /etc/vfstab file has seven fields, which are described in the following table. Field Name Description device to mount This field identifies one of the following:The block device name for a local UFS file system (for example, /dev/dsk/c0t0d0s0). The resource name for a remote file system (for example, myserver:/export/home). For more information about NFS, see System Administration Guide: IP Services. The block device name of the slice on which to swap (for example, /dev/dsk/c0t3d0s1). A directory for a virtual file system. device to fsck The raw (character) device name that corresponds to the UFS file system identified by the device to mount field (for example, /dev/rdsk/c0t0d0s0). This field determines the raw interface that is used by the fsck command. Use a dash (-) when there is no applicable device, such as for a read-only file system or a remote file system. mount point Identifies where to mount the file system (for example, /usr). FS type Identifies the type of file system. fsck pass The pass number used by the fsck command to decide whether to check a file system. When the field contains a dash (-), the file system is not checked. Currently, the fsck pass value in the /etc/vfstab file is ignored during the boot process.When the field contains a zero, UFS file systems are not checked. However, non-UFS file systems are checked. When the field contains a value greater than zero, the file system is always checked. All file systems with a value of 1 in this field are checked one at a time in the order they appear in the vfstab file. When the fsck command is run on multiple UFS file systems that have fsck pass values greater than 1 and the preen option (o p) is used, the fsck command automatically checks the file systems on different disks in parallel to maximize efficiency. Otherwise, the value of the pass number does not have any effect. mount at boot Set to yes or no for whether the file system should be automatically mounted by the mountall command when the system is booted. Note that this field has nothing to do with AutoFS. The root (/), /usr and /var file systems are not mounted from the vfstab file initially. This field should always be set to no for these file systems and for virtual file systems such as /proc and /dev/fd. mount options A list of comma-separated options (with no spaces) that are used for mounting the file system. Use a dash (-) to indicate no options. For a list of commonly used mount options, see Table 18–2. You must have an entry in each field in the /etc/vfstab file. If there is no value for a field, be sure to specify a dash (-). Otherwise, the system might not boot successfully. Similarly, white space should not be used as a field value. The following sections describe how to mount a file system by adding an entry in the /etc/vfstab file or by using the mount command from the command line.You can determine which file systems are already mounted by using the mount command.$ mount [ -v ]The v displays the list of mounted file systems in verbose mode.This example shows how to use the mount command to display information about the file systems that are currently mounted.$ mount / on /dev/dsk/c0t0d0s0 read/write/setuid/intr/largefiles/xattr/onerror=... /devices on /devices read/write/setuid/dev=46c0000 on Thu Sep ... /system/contract on ctfs read/write/setuid/devices/dev=43c0001 ... /usr on /dev/dsk/c0t0d0s6 read/write/setuid/intr/largefiles/xattr/... /proc on /proc read/write/setuid/dev=4700000 on Thu Sep 2 ... /etc/mnttab on mnttab read/write/setuid/dev=47c0000 on Thu Sep 2 ... /etc/svc/volatile on swap read/write/setuid/devices/xattr/dev=4480001 ... /system/object on objfs read/write/setuid/devices/dev=44c0001 ... /dev/fd on fd read/write/setuid/dev=4800000 on Thu Sep 2 ... /var/run on swap read/write/setuid/xattr/dev=1 on Thu Sep 2 ... /tmp on swap read/write/setuid/xattr/dev=2 on Thu Sep 2 ... /stuff on /dev/dsk/c0t0d0s5 read/write/setuid/intr/largefiles/xattr... /export/home on /dev/dsk/c0t0d0s7 read/write/setuid/intr/largefiles/... /home/rimmer on pluto:/export/home/rimmer remote/read/write/setuid/xattr/... $ Become superuser or assume an equivalent role. Create a mount point for the file system to be mounted, if necessary.# mkdir /mount-pointThere must be a mount point on the local system to mount a file system. A mount point is a directory to which the mounted file system is attached. Edit the /etc/vfstab file and add an entry. Ensure that you do the following:Separate each field with white space (a space or a tab). Specify a dash (-) if a field has no contents. Save the changes. For detailed information about the /etc/vfstab field entries, see Table 18–3.Because the root (/) file system is mounted read-only by the kernel during the boot process, only the remount option (and options that can be used in conjunction with remount) affect the root (/) entry in the /etc/vfstab file. The following example shows how to mount the disk slice /dev/dsk/c0t3d0s7 as a UFS file system to the mount point /files1. The raw character device /dev/rdsk/c0t3d0s7 is specified as the device to fsck. The fsck pass value of 2 means that the file system will be checked, but not sequentially. #device device mount FS fsck mount mount #to mount to fsck point type pass at boot options # /dev/dsk/c0t3d0s7 /dev/rdsk/c0t3d0s7 /files1 ufs 2 yes -The following example shows how to mount the /export/man directory from the system pluto as an NFS file system on mount point /usr/man. Neither a device to fsck nor a fsck pass is specified because it's an NFS file system. In this example, mount options are ro (read-only) and soft.#device device mount FS fsck mount mount #to mount to fsck point type pass at boot options pluto:/export/man - /usr/man nfs - yes ro,softThe following example shows how to mount the root (/) file system on a loopback mount point, /tmp/newroot. LOFS file systems must always be mounted after the file systems that are in the LOFS file system. #device device mount FS fsck mount mount #to mount to fsck point type pass at boot options # / - /tmp/newroot lofs - yes - Become superuser or assume an equivalent role. Mount a file system listed in the /etc/vfstab file.# mount /mount-pointwhere /mount-point specifies an entry in the mount point or device to mount field in the /etc/vfstab file. It is usually easier to specify the mount point. The following example shows how to mount the /usr/dist file system that is listed in the /etc/vfstab file.# mount /usr/dist The following example shows the messages that are displayed when you use the mountall command and the file systems are already mounted.# mountall /dev/rdsk/c0t0d0s7 already mounted mount: /tmp already mounted mount: /dev/dsk/c0t0d0s7 is already mounted, /export/home is busy, or the allowable number of mount points has been exceededWhen using the mountall command, all the file systems with a device to fsck entry are checked and fixed, if necessary, before they are mounted.The following example shows how to mount all the local systems that are listed in the /etc/vfstab file.# mountall -l # mount / on /dev/dsk/c0t0d0s0 read/write/setuid/intr/largefiles/xattr/onerror=... /devices on /devices read/write/setuid/dev=46c0000 on Thu Sep ... /system/contract on ctfs read/write/setuid/devices/dev=43c0001 ... /usr on /dev/dsk/c0t0d0s6 read/write/setuid/intr/largefiles/xattr/... /proc on /proc read/write/setuid/dev=4700000 on Thu Sep 2 ... /etc/mnttab on mnttab read/write/setuid/dev=47c0000 on Thu Sep 2 ... /etc/svc/volatile on swap read/write/setuid/devices/xattr/dev=4480001 ... /system/object on objfs read/write/setuid/devices/dev=44c0001 ... /dev/fd on fd read/write/setuid/dev=4800000 on Thu Sep 2 ... /var/run on swap read/write/setuid/xattr/dev=1 on Thu Sep 2 ... /tmp on swap read/write/setuid/xattr/dev=2 on Thu Sep 2 ... /stuff on /dev/dsk/c0t0d0s5 read/write/setuid/intr/largefiles/xattr... /export/home on /dev/dsk/c0t0d0s7 read/write/setuid/intr/largefiles/...The following example shows how to mount all the remote file systems that are listed in the /etc/vfstab file.# mountall -r # mount / on /dev/dsk/c0t0d0s0 read/write/setuid/intr/largefiles/xattr/onerror=... /devices on /devices read/write/setuid/dev=46c0000 on Thu Sep ... /system/contract on ctfs read/write/setuid/devices/dev=43c0001 ... /usr on /dev/dsk/c0t0d0s6 read/write/setuid/intr/largefiles/xattr/... /proc on /proc read/write/setuid/dev=4700000 on Thu Sep 2 ... /etc/mnttab on mnttab read/write/setuid/dev=47c0000 on Thu Sep 2 ... /etc/svc/volatile on swap read/write/setuid/devices/xattr/dev=4480001 ... /system/object on objfs read/write/setuid/devices/dev=44c0001 ... /dev/fd on fd read/write/setuid/dev=4800000 on Thu Sep 2 ... /var/run on swap read/write/setuid/xattr/dev=1 on Thu Sep 2 ... /tmp on swap read/write/setuid/xattr/dev=2 on Thu Sep 2 ... /stuff on /dev/dsk/c0t0d0s5 read/write/setuid/intr/largefiles/xattr... /stuff on /dev/dsk/c0t0d0s5 read/write/setuid/intr/largefiles/xattr... /export/home on /dev/dsk/c0t0d0s7 read/write/setuid/intr/largefiles/... /home/rimmer on pluto:/export/home/rimmer remote/read/write/setuid/xattr/... Become superuser or assume an equivalent role. Create a mount point for the file system to be mounted, if necessary.# mkdir /mount-pointThere must be a mount point on the local system to mount a file system. A mount point is a directory to which the mounted file system is attached. Mount the UFS file system.# mount [-o mount-options] /dev/dsk/device-name /mount-pointo mount-optionsSpecifies mount options that you can use to mount a UFS file system. For a list of options, see Table 18–2 or mount_ufs1M. /dev/dsk/device-nameSpecifies the disk device name for the slice that contains the file system (for example, /dev/dsk/c0t3d0s7). To view slice information for a disk, see How to Display Disk Slice Information. /mount-pointSpecifies the directory on which to mount the file system. The following example shows how to mount /dev/dsk/c0t3d0s7 on the /files1 directory.# mount /dev/dsk/c0t3d0s7 /files1 When you mount a file system, the largefiles option is selected by default. This option enables you to create files larger than 2 Gbytes. Once a file system contains large files, you cannot remount the file system with the nolargefiles option or mount it on a system that is running Solaris 2.6 or compatible versions, until you remove any large files and run the fsck command to reset the state to nolargefiles.This procedure assumes that the file system is in the /etc/vfstab file. Become superuser or assume an equivalent role. Create a mount point for the file system to be mounted, if necessary.# mkdir /mount-pointThere must be a mount point on the local system to mount a file system. A mount point is a directory to which the mounted file system is attached. Ensure that no large files exist in the file system.# cd /mount-point # find . -xdev -size +20000000 -exec ls -l {} \;where /mount-point identifies the mount point of the file system you want to check for large files. Remove or move any large files in this file system to another file system, if necessary. Unmount the file system.# umount /mount-point Reset the file system state.# fsck /mount-point Remount the file system with the nolargefiles option.# mount -o nolargefiles /mount-point The following example shows how to check the /datab file system and remount it with the nolargefiles option.# cd /datab # find . -xdev -size +20000000 -exec ls -l {} \; # umount /datab # fsck /datab # mount -o nolargefiles /datab Become superuser or assume an equivalent role. Create a mount point for the file system to be mounted, if necessary.# mkdir /mount-pointThere must be a mount point on the local system to mount a file system. A mount point is a directory to which the mounted file system is attached. Ensure that the resource (file or directory) is available from a server.To mount an NFS file system, the resource must be made available on the server by using the share command. For information on how to share resources, see About the NFS Service in System Administration Guide: Network Services. Mount the NFS file system.# mount -F nfs [-o mount-options] server:/directory /mount-pointo mount-optionsSpecifies mount options that you can use to mount an NFS file system. See Table 18–2 for the list of commonly used mount options or mount_nfs1M for a complete list of options. server:/directorySpecifies the server's host name that contains the shared resource, and the path to the file or directory to mount. /mount-pointSpecifies the directory on which to mount the file system. The following example shows how to mount the /export/packages directory on /mnt from the server pluto.# mount -F nfs pluto:/export/packages /mnt Use the following procedure to mount a PCFS (DOS) file system from a hard disk. Become superuser or assume an equivalent role. Create a mount point for the file system to be mounted, if necessary.# mkdir /mount-pointThere must be a mount point on the local system to mount a file system. A mount point is a directory to which the mounted file system is attached. Mount the PCFS file system.# mount -F pcfs [-o rw | ro] /dev/dsk/device-name:logical-drive /mount-pointo rw | roSpecifies that you can mount a PCFS file system read/write (rw) or read-only (ro). If you do not specify this option, the default is rw. /dev/dsk/device-nameSpecifies the device name of the whole disk (for example, /dev/dsk/c0t0d0p0). logical-driveSpecifies either the DOS logical drive letter (c through z) or a drive number (1 through 24). Drive c is equivalent to drive 1 and represents the primary DOS slice on the drive. All other letters or numbers represent DOS logical drives within the extended DOS slice. /mount-pointSpecifies the directory on which to mount the file system. Note that the device-name and logical-drive must be separated by a colon. The following example shows how to mount the logical drive in the primary DOS slice on the /pcfs/c directory. # mount -F pcfs /dev/dsk/c0t0d0p0:c /pcfs/cThe following example shows how to mount read-only the first logical drive in the extended DOS slice on the /mnt directory.# mount -F pcfs -o ro /dev/dsk/c0t0d0p0:2 /mnt The unmounting of a file system removes it from the file system mount point, and deletes the entry from the /etc/mnttab file. Some file system administration tasks cannot be performed on mounted file systems. You should unmount a file system when the following occurs:The file system is no longer needed or has been replaced by a file system that contains more current software. You need to check and repair the file system by using the fsck command. For more information about the fsck command, see Chapter 21, Checking UFS File System Consistency (Tasks).File systems should be unmounted before doing a complete backup. For more information about doing backups, see Chapter 24, Backing Up Files and File Systems (Tasks).File systems are automatically unmounted as part of the system shutdown procedure. In an emergency situation, you can use the umount f option to forcibly unmount a busy file system. This practice is not recommended under normal circumstances because the unmounting of a file system with open files could cause a loss of data. This option is only available for UFS and NFS file systems.The prerequisites for unmounting file systems include the following:You must be superuser or assume an equivalent role. A file system must be available for unmounting. You cannot unmount a file system that is busy. A file system is considered busy if a user is accessing a directory in the file system, if a program has a file open in that file system, or if the file system is being shared. You can make a file system available for unmounting by doing the following:Changing to a directory in a different file system. Logging out of the system. Using the fuser command to list all processes that are accessing the file system and to stop them, if necessary. For more details, see How to Stop All Processes Accessing a File System.Notify users if you need to unmount a file system that they are using. Unsharing the file system. For information about unsharing a file system, see unshare1M. To verify that you unmounted a file system or a number of file systems, examine the output from the mount command.$ mount | grep unmounted-file-system $ Become superuser or assume an equivalent role. List all the processes that are accessing the file system so that you know which processes you are going to stop.# fuser -c [ -u ] /mount-pointcReports on files that are mount points for file systems and any files within those mounted file systems. uDisplays the user login name for each process ID. /mount-pointSpecifies the name of the file system for which you want to stop processes. Stop all processes that are accessing the file system.# fuser -c -k /mount-pointA SIGKILL is sent to each process that is using the file system.You should not stop a user's processes without first warning the user. Verify that no processes are accessing the file system.# fuser -c /mount-point The following example shows how to stop process 4006c that is using the /export/home file system.# fuser -c /export/home /export/home: 4006c # fuser -c -k /export/home /export/home: 4006c # fuser -c /export/home /export/home: Use the following procedure to unmount a file system, except for the root (/), /usr, or /var file systems.The root (/), /usr, and /var file systems can be unmounted only during a shutdown. The system needs these file systems to function. Ensure that you have met the prerequisites listed in Prerequisites for Unmounting File Systems. Unmount the file system.# umount /mount-pointwhere /mount-point is the name of the file system that you want to unmount. This can be one of the following: The directory name where the file system is mounted The device name path of the file system The resource for an NFS file system The loopback directory for an LOFS file system The following example shows how to unmount a local home file system.# umount /export/homeThe following example shows how to unmount the file system on slice 7.# umount /dev/dsk/c0t0d0s7The following example shows how to forcibly unmount the /export file system.# umount -f /export # The following example shows how to unmount all file systems in the /etc/vfstab file, except for the root (/), /proc, /var, and /usr file systems.# umountallAll file systems are unmounted, except for those file systems that are busy.