Disk and partition management notes on sun solaris

# Disk management

Disks consist of the folowing
1. Tracks    -  concentric rings on each platter
2. Cylinders   -  groups of tracks
3. Sectors/Blocks  - 512 byte blocks



## Disk Partitions

Note: Partitions within Solaris are AKA slices

Note: x86 PCs are limited to 4 FDISK primary partitions/ Solaris requires 1 FDISK partition for its use
 and slices wil be created within the FDISK partition


Note: on x86, Solaris uses a Volume Table of Contents(VTOC) to represent various slices within the lone FDISK partition on the disk
Note: On Sparc, Solaris uses VTOC to represent ALL slices on disk, NOT within lone FDISK partition


Slices rules within x86 using VTOC:
10 Slices(0-9) MAX maybe created when using VTOC on x86
10 Slices(0-9) MAX maybe create when using VTOC on x86
Slices 2,8,9 are reserved
Slice 2 - VTOC
Note: VTOC represent the disk's label and occupies Slice 2
0,1,3,4,5,6,7 available

Default Sclice allocation:
0 - /
3 - /var
7 - /export/home

Note: Disk '/ (root) & /usr' mount points is known as 'system disk' which wil be used to boot Solaris
All other disks are known as secondary disks


### Print VTOC/Disk Label - using prtvtoc
prtvtoc /dev/dsk/c0t0d0s0

c0t0d0s0
c0 - Controller #  -  this is the first controller on the system
t0 - an identifier for bus-oriented controller - first target or id on the bus - first hard disk
d0 - represents disk #
s0 - represent the slice/partition #

### Create Unix file system (UFS) for new slices
after creating a new slice with format command (and partition part)

newfs /dev/rdsk/c0t0d0s4

### Create mount points for newly created filesystem

mkdir /data1
mount /dev/rdsk/c0t0d0s4 /data1

on /etc/vfstab add:
/dev/rdsk/c0t0d0s4     /dev/rdsk/c0t0d0s4   /data1   ufs  2    yes   -

and mount -a


#### Steps to partition and create a filesystem

1- run format to identify connected disk
2- for x86, ensure the presence of fdisk partition
3- create desired slices using 'partition' sub-menu
4- label each disk after altering partition table
5- use n'newfs' with raw location to create UFS filesystem for each slice

6- Mount each UFS slice to user-space directory
7- update /etc/vfstab file to allow changes to persist



##How to determine the filesystem

1- fstyp /dev/dsk/c0t0d0s0
2- grep mount point from /etc/vfstab
3- cat /etc/mnttab     - displays currently mounted filesystems



### Temporary filesystem
TempFS provides in-memory, very fast, storage and boosts application performance

1- Determine the amount of available memory
 -  prtconf | grep -i memory
 

2- Execute mount command
 -

mount -F tmpfs -osize=100m swap /tmpdata


df -h | grep -i tempdata

tempfs will die with reboot



### Swap creation - files & partition
swap -l    #shows which device is configured for swap and the space
swap -s    #shows allocated, available and used space

### swap file creation

1- mkfile - creates zero-filled swap file
2- swap -a   - activates the swap file

mkfile 512m /data2/swap2
swap -a /data2/swap2

swap -d /data2/swap2   - removes swap space