File System |
Description |
FAT |
Partition can be upto 4 GB and maximum file size limit 2 GB |
FAT32 |
Partition can be upto 32 GB and maximum file size limit 4GB |
NTFS |
File and partition can be of 2 TB |
NTFS features:
- File and folder level security (folder 6 security, file – 5 security)
- Disk quota (disk space manage for user)
- Disk compression
- File encryption
- Shadow copies restore (only in 2003)
Command line commands to manage disks:
Command |
Description |
DiskPart |
Manage disks, partitions, and volumes by using scripts or direct input from the command prompt |
Defrag |
Locates and consolidates fragmented boot files, data files, and folders on localvolumes |
Cscript |
Allows you to run scripts from the command-line-based script host. |
Storage Type (Type of Disks):
1. Basic (supported since MS DOS to even now) |
2. Dynamic (supported by 2000, xp, 2003) |
Partition is created (primary, extended) |
Volume is created (simple, spanned, mirror, striped, raid5) |
Support multi-booting |
Doesn’t support multi-booting |
Partition size cannot be increased (extended) |
Volume size can be increased |
Doesn’t provide fault tolerance (redundancy) |
Provide fault tolerance (redundancy) |
Partition can be formatted in FAT, FAT32 and NTFS etc. |
volume can only be formatted only in NTFS |
Condition:
4 primary 0 extended
3 primary 1 extended
2 primary 1 extended
1 primary 1 extended
Dynamic disk:
Dynamic disk storage is a new feature in winxp, 2000 & 2003 which consist of dynamic volumes and provide fault tolerent features in case of disk failure. It supports five types of dynamic volume which are as follows:
Simple volume:
- Created only from a single dynamic disk space.
- Simple volume size can be extended from unallocated space of same or another dynamic disk.
- It does not provide fault tolerance features.
Spanned volume:
- Created from two or more (upto 32) dynamic disk.
- Data is written sequencly, it means once the one disk is full data is written to another disk and so on.
- It is not fault tolerant. If any of the disks fails from spanned volume the entire data is lost.
Striped volume (RAID 0):
- Created from two or more (upto 32) dynamic disk.
- Data is written alternately and evenly (in 64 KB stripes) across the dynamic disk (first 64 KB is written to the first disk, next 64 KB is written to the second disk and so on).
- Provide best performance.
- It is not fault tolerant. If any of the disks fails from spanned volume the entire data is lost.
Mirrored volume (RAID 1):
- Created from two dynamic disks.
- Data is written on both disks at the same time. Data on the second disk is just a duplicate copy of the first disk. It means for writing 50 MB of data it takes 100 MB of space.
- It is fault tolerant. If any of the disks fails, data can be accessed from another disk.
Note: You cannot extend mirrored volume.
System and boot partition can be mirrored. (only RAID 1)
RAID 5 (Striped volume with parity):
- Created from 3 or more (upto 32) disks.
- Cannot be used for system or boot partition
- Data is written sequencly in strip and parity (data recovery information) information of disk is not written on the same disk but on the other.
- It provides redundancy (fault tolerance) and good read performance. If one of the disks fails data is automatically regenerated.
- It uses 33% disk space for pairity in the case of three dynamic disk.
Space used = (n-1)z (n = no. of disk, z = capacity of disk)
Note: Volume size only extend in the NTFS file system.
http://www.ibeast.com/content/tools/RaidCalc/RaidCalc.asp (RAID Calculator)
Note:
RAID = Redundant Array of Independent Disks
Overhead refers to the amount of extra (or "wasted") disk space required to add fault tolerance.
RAID5 volumes use one disk in the set for fault tolerance (a 3-Disk set has 33% overhead, a 4-Disk set has 25% overhead).
Mirrored volumes have 50% overhead (meaning one disk in two is used for fault tolerance).
You should know the following facts about disk management:
- When you move a disk that has been installed and used in another computer, you might need to import the disk. In Disk Management, right-click the disk and choose Import Foreign Disks.
- Using Disk Management, you can analyze a disk for defragmentation before using the defragmentation utility.
- Use Disk Management to reactivate volumes in a RAID-5 configuration. This improves performance after a disk in the configuration has been replaced.
You should know the following facts about recovering failed disks:
To recover a failed disk in a mirror configuration:
1. Break the mirror.
2. Delete the failed disk.
3. Recreate the mirror to a new disk (make sure the disk is upgraded to a dynamic disk first).
To recover a failed disk in a RAID5 configuration:
1. Repair the volume on a new dynamic disk.
2. Delete the old disk.
To recover a volume in a failed operating system:
1. Move the disk to a new machine.
2. Import the foreign disk on the new system.
Volume Mount Points
A volume mount point allows you to use another partition in the computer and represent it as a
folder in an existing partition. This allows you a great deal of flexibility when you need to
expand storage requirements.
You should know the following facts about volume mount points:
- Both partitions must be formatted with NTFS.
- You can use either partitions on basic disks or volumes on dynamic disks for volume mount points.
- The folder on the source partition must be empty.
- The target partition must not have a drive letter.
- Multiple folders can reference the same target partition.
