Block Storage

• Block Storage represents the disks
• Every disk needs a filesystem to access the contents of disk
  • Windows:
    • NTFS (NT File system)
  • Linux:
    • XFS
    • ext4
    • btrfs
    • zfs

Disk storage in AWS and Azure

• Overview
  
• AWS:
  • EBS (persistent/non ephemeral):
    • OS disk/root disk has to be EBS
    • EBS and EC2 instance should be in the same zone
  • Instance store (temporary/ephemeral)
    • This is supported only by few instance types
• Azure:
  • Disks (persistent/non ephemeral)
    • OS disk is generally non ephemeral
    • Disk and VM can be
      • Region supports zones: should be in same zone
      • Region without zones: should be in same region
  • Local disk/Temp disk (temporary/ephemeral)
    • This is supported by many instance types
• How many data disks can we add to azure vm
  • azure vm: depends on instance size
• how many ebs volumes can be added to aws ec2
• aws: max 28 for most of sizes
• What is full backup and incremental backup

Snapshot

• Snapshot represents the backup of the disk
• Snapshots are stored at regional level
• In Azure we have option to take full/incremental backups
• In AWS, the backups are incremental in nature
• Note:
  • Deleting older versions in incremental backups will not lead to data loss, whereas deleting latest versions will lead to data loss