CHAPTER 3.4 Flashcards
Direct attached storage (DAS)
- Storage consists of internal/external disks connected directly to the storage controllers in the host.
- Used by SCSI AND SATA
Advantages of DAS
- Easy to configure.
- Inexpensive
Disadvantages of DAS
- Slower
- Isolated because the disks are attached to a single server.
Network attached storage (NAS)
- An Ip based, dedicated, high performance file sharing and storage device.
- Uses specialized OS that is optimized for file I/O
- Support file sharing protocol
Advantages for Nas
- Relatively inexpensive
- Easy to configure.
- Centralized storage at an affordable price
Disadvantages of NAS
- Slower access time
- Often not an enterprise solution
Storage Area Network (SANs)
A high-speed, dedicated network of servers and shared storage devices
Advantages of SAN
- Fastest access times
- Easily expandable
- Centralized storage
- High level of redundancy
Disadvantages of SAN
- More expensive
- Requires specialized skills.
Fibre Channel SAN
A highspeed network technology
* Can support up to 128GB/s.
* Uses FC switches to form a fabricated switch.
* Runs on optical fibre cut but can also run on copper cabling
Fibre Channel SAN
Used to connect data storage to servers between data centres.
High scalable and can support up to 15 million devices.
IP SAN Protocol: ISCSI
Supports access to remote, SCSI-based storage devices.
Can run over a pre-existing switching and IP infrastructure.
Components of iSCSI
- iSCSI initiator
- iSCSI target
- IP network
Storage pool
Can span multiple drives and can be expanded or reduced as needed.
Support RAID
File System
Controls the way files are named and how they are placed logically for storage and retrieval.
Has different characteristics such as structure, logic, security and size limitation.
