File System: It is an option in which we can format a disk space, according to the user requirement.
- The default file system in Solaris is - UFS (Unix File System)
Types of File System:
1. Disk Based File System (ex: UFS)
2. Network Based File System (NFS)
3. Memory Based File System (ex: CACHEFS, TEMPFS, Auto FS)
Flag Status:
1. Write Mount: ex: Disk based FS
2. Write Unmount: ex: Memory based FS
3. Read Mount
4. Read Unmount
Types of Devices:
1. Logical Devices (/dev): This logical device names are for administrative reference and these are symbolically linked with physical devices. All the logical devices are under /dev directory.
2. Physical Devices (/devices): These are for kernel reference and All the physical device names stored under /device directory.
Formates of a disk:
1. rdsk (raw disk): The disk before formatting will be under raw format, identified as "rdsk".
2. dsk (block disk): The disk after formatting, is known as block device, it is identified as "dsk".
commands used to create file system:
1. #format: is command line utility which shows all the available disks in a system.
2. #newfs: is a command line utility which is used to format a disk under "ufs". when you format a disk by using a "newfs" by default on directory will create called "Lost+Found". which contain un saved data, which is used to recover data in next reboot.
3. #mount: mount in the FS means, attaching the file system to a directory under root.
4. #mountall: It is used to mount all the permanent FS.
5.#umount: unmount the FS
6.#umountall: It is used to umount all the FS except root & root user.
7. /etc/mnttab: when you create a file system & mount, by default one file get updated automatically, that is /etc/mnttab, the entries in mnttab are temporary.
8. /etc/vfstab: If you want to make it permanent, we have to update a file called /etc/vfstab.
to view the content of the file system "cat /etc/mnttab" use
9. #fsck: (File system check): used to check inconsistency file system (unmounted FS).
i. serial checking
ii. parallel checking
Steps for File System creation:
Solaris1# Format
specify disk (enter its number): 0
Format> p // partition
Partition> p // print
Partition> 4 // Select the slice
partition id tag [unassigned]: //leave it blank it defaultly take unassigned
partition permission flags [wm]: //leave it blank it defaultly take wm
enter starting cylinder number cy[0]: 514
enter partition size: 500m //500 MB
// The entered information about partition ID, permission flags and partition size will be on the RAM, in order to update to the kernel we need to "label" it.
partition> l // l- label
ready to the label disk, continue? Y // now it is into the kernal, before it was in RAM
partition> q // quit from partition
format> q // quit from format & back to the Solaris1
Solaris1# newfs /dev/rdsk/c0t0d0s4 // to construct new file system
construct new filesystem (y/n)? Y
Solaris1# df -h (or) df -k // to view file system, no slice(s4) visible, bcoz not yet mounted
Solaris1# mkdir /sunny
Solaris1#mount /dev/dsk/c0t0d0s4 /sunny
Solaris1# df -h // to view file system, now slice(s4) visible, bcoz mounted to sunny
Solaris1# cd /sunny
Solaris1# ls //no files created yet
Solaris1#touch 1 2 3 // create files 1 2 3
note: /etc/mnttab: when you create a file system & mount, by default one file get updated automatically, that is /etc/mnttab, the entries in mnttab are temporary.
If you want to make it permanent, we have to update a file called /etc/vfstab.
//to view the content of the file system "cat /etc/mnttab" use
Solaris1#cat /etc/mnttab
/dev/dsk/c0t0d0s4 /sunny
Solaris1# umount /sunny // to unmount the file system
Solaris1# df -h
now there is no s4 slice mounted
Solaris1# vi /etc/vfsstab //vfstab : virtual file system table
device device to mount FS fsck mount mount
tomount fsck point type pass at boot options
------------------------------------------------------------------------------------
/dev/dsk/c0t0d0s4 /dev/rdsk/c0t0d0s4 /sunny UFS 1 Yes -
1. device to mount: It refers to block device
2. device to fsck: file system checking is always done on unmounted FS.
3. mount point: refers to the directory on which the FS is mounted.
4. FS type: default is UFS
5. fsck pass: it is done in two modes i. serial check ii. parallel check
6. mount at boot: it is used to specify whether you want to mount the file system at next reboot or not
7. mount options: '-' it refers to default options. i.e FS permission RW, support the large file.
