Azure Classroomnotes 24/Nov/2022

Azure Managed Disks

• In Azure We have two disks based on where they are created from
  • Temp Disk (Created on the same physical server as vm):
    • Data in temp disk is accesible faster when compared to other disk types
    • Data will be lost once we shutdown/delete
    • Temp Disks can be used for data which donot require persistence
    • Size of temp disk is decided by the instance size you select.
    • On the windows machine the temp disk is mounted on D drive
    • On the linux machine it is mounted on /mnt
  • Os Disk: Os Disk will be created generally from a different physical server
  • Data Disks: Additional disks that can be added to VM and they are also attached from a different physical server
    • Number of Data disks that can be attached is decided again by instance size selected
      
• Disk Types supported by Azure
  • Standard:
    • HDD
    • SSD
  • Premium
    • SSD
  • Ultra
    • SSD
• Disk Types Comparision Refer Here
• Any vm instance size with letter s in it supports premium disks.

Experiment

• Lets create a linux vm and explore options w.r.t to disk
• Now we have selected standard_B1s which supports 2 data disks and temp disk of size 4 GB and max iops => 320
  
• While creating VM, we can choose disk type
  • Premium SSD (only for instances with premium disk supported i.e with s )
  • Standard SSD
  • Standard HDD
• Linux treats disks as block devices. Right now to this instance we two disks provided by azure
  
• In linux the block devices are mounted to folders
  
• Lets add one more data disk
  
  
  
  

Terms

• Units: GiB, TiB, MiB …
• IOPS: Input Output Operations per second
• Throughput: The size of data that can be read/write per second

Throughput = (Block size) * IOPS