Storage is another fundamental core IT infrastructure component that is found in both on-prem and cloud datacenters. In this post we will learn the fundamental concepts and basics of Storage infrastructure. We will explore common storage devices and systems and how they are attached and are accessed both in the cloud and local datacenters.
In the previous posts we learned the basics and fundamental concepts of Cloud Computing and Virtualization. In this post we will learn the below topics about Storage infrastructure – a core component in Cloud Computing.
- What is a Storage Device
- Types of Storage Interfaces
- Introduction to Cloud Object Storage
- Storage Management Techniques
- Storage provisioning Techniques
- Storage Access Methods
- Storage Network Technologies
- Storage Access Protocols
Types of Storage Interfaces
Storage Devices uses various types of interface technologies to communicate with the servers over the network. Over the years, multiple interface types are designed to improve the performance and data access speed based on the data access patterns form the storage devices. Below are some of the commonly used storage interfaces.
Small Computer Systems Interface (SCSI)
- SCSI is a parallel interface technology found in PCs or server systems and it has been in use for decades and is still popular today.
- Many types of SCSI interfaces have been evolved over the years with the variation in bus width and data transfer speeds. SCSI is a data bus that allows for multiple devices to be connected on the same cable.
- A combination of these interface types known as Serial Attached SCSI (SAS) allows for the SCSI commands to be sent over a serial interface.
- SAS is a direct replacement for the SCSI parallel cable and offers much higher transfer rates.
Advanced Technology Attachment (ATA)
- ATA is a standardized interface for storage to system interconnections and it is commonly found on storage devices that are directly connected to a server or computer.
- ATA drives are integrated with the controller which are also called as Integrated Drive Electronics (IDE) interfaces.
- Commonly used drive designs with ATA/IDE interfaces are Hard Disk drives, CD-ROM, DVD, and tape drives.
Serial Advanced Technology Attachment (SATA)
- SATA is a current technology which is found in many production data networks.
- It is a serial link connection to the drive instead of the older parallel interface found in SCSI and IDE.
Fibre Channel Interface (FC)
- This is the another common type of interface found in todays datacenters supporting cloud applications and large enterprises.
- Fibre Channel is a SAN protocol that encapsulates the SCSI command set and allows for cloud servers to access storage resources remotely.
Read more about Different SAN protocols and architectures
Disk Performance and Access Speeds
- Disk performance and access speed are the important factors which differentiates the usage of above storage devices and interfaces. The measurement of performance is defined as the transfer speed of data to and from the storage device to the device initiating the storage request.
- Many factors come together to affect the performance of a disk system. The time it takes to find the data on the disk, known as the seek time which is an important metric.
- The actual speed of the bus also needs to be taken into consideration, and the disk rotation speed has a significant effect on the transfer rate of the data as well.
- The type of redundancy techniques that are implemented can play a significant role in disk performance.
- The read/write speed of the data to a storage device can also have a major impact on overall system performance.
- Storage performance can also be measured based on the applications that require high read performance, whereas others may rely on fast writing of data to storage.