What is World Wide Name (WWN)

A World Wide Name, or WWN, is a 64-bit address used in fibre channel networks to uniquely identify each element in a Fibre Channel network.

Soft Zoning utilizes World Wide Names to assign security permissions.

The use of World Wide Names for security purposes is inherently insecure, because the World Wide Name of a device is a user-configurable parameter.

For example, to change the World Wide Name (WWN) of an Emulex HBA, the users simply needs to run the `elxcfg` command.

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HEAT Report Generation (Host Environment Analysis Tool)

The Host Environment Analysis Tool (HEAT) is a Web-based application that Processes the output of the EMCReports script for the Windows Hosts.

In order to generate a HEAT report login to the EMC POWERLINK website:


Once you are successfully logged into the site with the valid user name and password, kindly follow the below link:

Home > Support > Product and Diagnostic Tools > Environment Analysis Tools > Host Environment Analysis Tool (HEAT)

Visit the Host Environment Analysis Tool (HEAT) Website


Upload the latest EMC grab report and then you will find the complete HEAT report. You could also send the same file to your registered mail is.

EMC Grabs Report Downloads Links

EMC Grabs Reports Latest Version downloads for Windows, Solaris, Linux, AIX, HP-UX, IRIX, REliantUNIX, OSF1 and for Heat Reports as well, find below the download link –

You need to have user id and password to login into http://www.powerlink.emc.com


To view this FTP site in Windows Explorer, click Page, and then click Open FTP Site in Windows Explorer.


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
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:
Server clustering
Messaging applications
Data replication
GRID computing
Data warehousing
Recovery archives


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.