NAS Vs SAN

NAS – Network Attached Storage:

1. Any machine that can connect to the LAN can use NFS, CIFS or HTTP protocol to connect to a NAS and share files.
2. A NAS identifies data by file name.
3. NAS allows greated sharing of information between disperate Operating systems such as Unix and NT.
4. File System handled by NAS head unit.
5. Backups and mirrors are done on files and not on blocks for savings in bandwidth and time.

SAN – Storage Area Network:

1. Only server class devices with SCSI Fibre channel can connect to the SAN.
2. SAN address data by disk block number and transfer raw disk blocks.
3. File sharing is operating system dependent and does not exist in many Operating systems.
4. File system handled by servers.
5. Backups and mirrors requires a block by block copy even if the block is empty.

Types of networks supported
NAS uses TCP/IP Networks: Ethernet, FDDI, ATM (perhaps TCP/IP over Fiber Channel someday)
SAN uses Fiber Channel

The Protocols
NAS uses TCP/IP and NFS/CIFS/HTTP
SAN uses Encapsulated SCSI

NAS works best for these types of applications:
File serving
File sharing
Users’ home directories
Content archiving
Metadata directories
E-mail repositories, such as enterprise .PST files
GRID computing (using 10 Gigabit Ethernet)
Peer-to-peer data sharing

SAN works best for these types of applications:
Databases
Server clustering
Messaging applications
Backup
Data replication
GRID computing
Data warehousing
Recovery archives

Basic Vs Dynamic Disk

Basic Vs Dynamic Disk

Basic Disk supported by all Windows Operating Systems.
Dynamic Disk supported by later version of windows including 2000, XP, 2003, etc.

Volume changes can be done on dynamic disk without reboot.
Any file system can be used for both the disks.
One can convert basic disk to dynamic. However, if you’ve converted the disk to dynamic, you cant revert to basic without first wiping and recreating the volume.

Basic disks contains primary partitions, extended partition and logical drives. Primary partition in Windows NT can support stripping and software RAID sets. However, in 2000, XP and 2003 dont support stripping and software RAID.

Dynamic Disks can create different type of volumes with dynamic disks.
Simple Volume -> Use space from single disk or hardware array volume.
Spanned Volume -> Non fault tolerant disk sets that use free space from multiple disk.
Striped Volume -> Non fault tolerant disk that stripe data across multiple disks.
Mirrored Volume -> Fault tolarent disk set that mirror data from one to another disk.
RAID 5 Volume -> Fault tolarent disk that stipes data across three or more disks including parity.

RAID

Short for Redundant Array of Independent (or Inexpensive) Disks, a category of disk drives that employ two or more drives in combination for fault tolerance and performance. RAID disk drives are used frequently on servers but aren’t generally necessary for personal computers. RAID allows you to store the same data redundantly (in multiple paces) in a balanced ay to improve overall performance.

There are number of different RAID levels:

  • Level 0 — Striped Disk Array without Fault Tolerance: Provides data striping (spreading out blocks of each file across multiple disk drives) but no redundancy. This improves performance but does not deliver fault tolerance. If one drive fails then all data in the array is lost.
  • Level 1 — Mirroring and Duplexing: Provides disk mirroring. Level 1 provides twice the read transaction rate of single disks and the same write transaction rate as single disks.
  • Level 2 — Error-Correcting Coding: Not a typical implementation and rarely used, Level 2 stripes data at the bit level rather than the block level.
  • Level 3 — Bit-Interleaved Parity: Provides byte-level striping with a dedicated parity disk. Level 3, which cannot service simultaneous multiple requests, also is rarely used.
  • Level 4 — Dedicated Parity Drive: A commonly used implementation of RAID, Level 4 provides block-level striping (like Level 0) with a parity disk. If a data disk fails, the parity data is used to create a replacement disk. A disadvantage to Level 4 is that the parity disk can create write bottlenecks.
  • Level 5 — Block Interleaved Distributed Parity: Provides data striping at the byte level and also stripe error correction information. This results in excellent performance and good fault tolerance. Level 5 is one of the most popular implementations of RAID.
  • Level 6 — Independent Data Disks with Double Parity: Provides block-level striping with parity data distributed across all disks.
  • Level 0+1 — A Mirror of Stripes: Not one of the original RAID levels, two RAID 0 stripes are created, and a RAID 1 mirror is created over them. Used for both replicating and sharing data among disks.
  • Level 10 — A Stripe of Mirrors: Not one of the original RAID levels, multiple RAID 1 mirrors are created, and a RAID 0 stripe is created over these.
  • Level 7: A trademark of Storage Computer Corporation that adds caching to Levels 3 or 4.
  • RAID S: (also called Parity RAID) EMC Corporation’s proprietary striped parity RAID system used in its Symmetrix storage systems.

NIC Teaming

NIC Teaming using HP NCU.

1. Perform the initial installation of HP Network Configuration Utility (NCU) and open the utility.
2. Select the network adapter ports for a team.
From the NCU main page, highlight two or more network adapter ports. Then, click the Team icon.
3. Set the team type Automatic.
a. Click the Properties icon on the NCU main page for the newly formed team (white team icon).
b. Under Team Type Selection on the Teaming Controls tab, notice that Automatic (Recommended) is
already chosen. This is the default setting for new teams.
c. Note the name assigned to the team in the Team Name window (for example, HP Network Team #1).
d. (Optional) Rename the team by changing the text in the Team Name window.
e. Click the OK button on the Team Properties page when finished.
4. Apply all changes.
a. Click the OK button on the NCU main page.
b. Click Yes when asked if all configuration changes should be applied.
c. Wait until the All Configuration Changes Were Made Successfully dialog box appears.
5. Assign an IP address to the team.
a. Open the Network Connections (in other words, Network and Dial-up Connections) window from the Control Panel.
b. Under Device Name (in the Details view), open the Properties page for the device with the same name as noted in step 3.
c. Assign the appropriate IP address information based on the connected network requirements.