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Disk Management: Basic and Dynamic Disks

 Basic Disks: Basic Disk only works with Partitions.

Most common storage types used with Windows Operating Systems., with Basic Partition you can create Primary, Extended or Logical Drives., you can also say it’s the Original disk.

In Basic Disk If a drive (ex: E: Drive) is used up we can format the drive without any issues and recreate the File System and data.

Dynamic Disks: Dynamic Disks works with Volumes.

It provides features which Basic Disk do not support., like the ability to create volumes that cover multiple disks.

Types of Dynamic Volumes:

1. Simple Volume: This can be extended.
2. Spanned Volumes: It can consists of upto 32 disks.
3. Striped Volumes: It can consists of upto 32 disks. ( RAID 0 ) [Block by block striping.
4. Mirrored: It only consists of two disks ( RAID 1 ) [Block by block mirroring]
5. Striped with Parity: It can consists of upto 32 disks. (RAID 5 )
   
   

• Simple Volumes:

        Simple volume is a kind of dynamic disk volume.

• Spanned Volumes: If one disk goes down all files are lost & whole library goes unavailable. It utilizes one disk at a time and when it fills it movies to the other disks.
  
  

• Striped Volumes: Condition -> All disk should be of same size.

        It utilizes all available disk at a time, still performance will be of 1 Disk times total disks., same as Spanned volumes if 1 disk fails whole library goes down.

• Mirrored Volumes: Condition -> Disk should be of same size.

        This is a fault tolerant volume, it makes use of two disk and it writes the same file to two disks., you can attach both disk to a controller drive (SCSI Controller ) two controller attaches to each drive for fault tolerant.

• Striped Volumes: RAID 5

        It writes a file to 3 disks (Ex: 1^st Disk, 2^nd Disk & 3^rd Disk) and saves a parity information to another disk. So when a disk falls all the data will be reconstructed using parity checksum.

Difference between Basic Disk and Dynamic Disk.

Basic Disk	Dynamic Disk
Industry Standard, Primary partition can be read by Unix/Linux.	Logical Disk Manager, easy to transfer disk to another server.
Single drive	Unlimited volumes
Laptops / Removable	Flexible volumes.

Adding and Breaking Mirrored Disks:

You can make use of Command line utility “Diskpart”, run Command prompt with admin privilege:
and type-> DISKPART

• DISKPART> Select Volume D:
  Output: Volume 2 is the selected volume.
• DISKPART>add disk3

Diskpart complete in adding a mirror to the volume.

• DISKPART>break disk2 (will break)
• DISKPART>break disk3 nokeep (this will delete the mirror)

Steps to Convert MBR disk to GPT disk:
 Run Command prompt with admin privilege:

• C:\>DISKPART

        Microsoft DiskPart version 6.1.7601
        Copyright (C) 1999-2008 Microsoft Corporation.
        On computer: Winadmin-LPT

• DISKPART> list disk
  Disk ###  Status         Size     Free     Dyn  Gpt
  --------  -------------  -------  -------  ---  ---
  Disk 0    Online          465 GB  1024 KB

• DISKPART> select disk 0
  Disk 0 is now the selected disk.

• DISKPART> list partition

          Partition ###  Type              Size     Offset
          -------------  ----------------  -------  -------
          Partition 1    Primary            100 MB  1024 KB
          Partition 2    Primary             65 GB   101 MB
          Partition 3    Primary            100 GB    65 GB
          Partition 0    Extended           300 GB   165 GB
          Partition 4    Logical            300 GB   165 GB

• DISKPART> select partition 0
  Partition 0 is now the selected partition.

• DISKPART> delete partition
• DISKPART> convert gpt

Disk checking utilities:

1. System File Checker tool (SFC.exe)
CMD> sfc /scannow

2. Check Disk from a Command Line to Check for and fix Disk Errors
CMD> chkdsk /f /r

Switches:
/F       Fixes errors on the disk.
/R       Locates bad sectors and recovers readable information (implies /F).

Interview Question:
How many primary partition you can have in Basic Disk?
Ans -> You can have 4 primary partition in Basic Disk, or 3 primary partition and 1 extended partition or logical partition.