A very common misperception is that iSCSI SANs are not as secure as Fibre Channel SANs. In fact, when logically or physically separated, iSCSI networks are just as secure as Fibre Channel.
iSCSI is sending SCSI commands in IP packets. To be more specific, iSCSI is designed to be a protocol for a storage initiator (usually a server) to send SCSI commands to a storage target (usually a tape or disk) over IP. iSCSI technology provides compelling price/performance in a simplified architecture while improving manageability in virtualized environments.
SCSI protocol is not designed to handle lost frames, or blocks. It expects them to arrive, no matter if they’re damaged (have CRC errors). IP or Ethernet will not deliver a frame which has CRC errors; behavior which is not compatible with what SCSI expects. This is why iSCSI uses TCP.
The way to improve performance of iSCSI is to use HBAs (Ethernet NIC) with TCP offload, which do all the necessary calculations on an embedded ASIC, significantly reducing the processing latency. Majority of storage arrays with iSCSI already make use of TCP offload, so some of the performance problems that you’re seeing are quite likely caused by a poor choice of Ethernet NIC in the server (or incorrect/badly configured NIC drivers). Broadcom NetXtreme II network adapters can be used for Iscsi Offload.
Specifically, iSCSI offers virtualized environments simplified deployment, comprehensive storage management and data protection functionality, and seamless VM mobility. Dell iSCSI solutions give customers the “Storage Direct” advantage – the ability to seamlessly integrate virtualization into an overall, optimized storage environment.
In Linux you can use iscsiadm command to login the ISCSI targets and allows to discover.In CentOS 5.1 adds over the 5.0 version is an updated iscsi-initiator-utils. It adds the “iface” context, which allows you to configure more than one physical interface for connection to iSCSI targets. With CentOS 5.0 the best alternative for redundant paths was to use the Linux bonding driver and create an active-standby bond between two interfaces. This is great for redundancy, but doesn’t provide and load balancing.
Dell’s PS Series group provides iSCSI-accessible block storage. With the latest version of the PS Series firmware and the addition of an EqualLogic FS7500, the same PS Series group can provide block storage and support for NAS (Network Attached Storage). FS7500 is integrated directly into the EqualLogic Group Manager to improve productivity, making it easy to configure and manage iSCSI, CIFS and NFS storage.
Easy To Follow Ideas About Search Engine Optimization That Will Really Help You
You could be the most ambitious person on the planet when it comes to creating a website with all the bells and whistles that people will love, but unless your visitors can find your site when they search specific terms, your efforts are just going to be wasted. Read these tips and make the most of your efforts.
On your website, headings are going to play a vital role in organizing information. So you need to use only a single H1 tag when you are putting your page together. You can use various subheading tags, like H2-H6, but keep things neat and clean by only using one main H1 tag.
To search engine optimize your website, don't include more than 150 internal linking hyperlinks on your home page. Too many internal links on one page can dilute a web page's search engine rank. Huge numbers of links also make it hard for visitors to find the information that they need quickly.
To ensure that your website is as easy as possible to crawl, keep your site architecture flat. Don't use too many sub folders, instead use descriptive names for each page. Keep your pages with the most competitive keywords in their names, close to the root folder, so they will gain a higher page rank.
A great way to optimize your search engine is to provide use internal links. This means you have an easy access to links within your own site. This provides an easier database for customers of viewers to use and will end up boosting the amount of traffic you have.
Find some SEO forums that take site review requests. Participate in the forums then ask fellow members to take look at your website. When someone you don't know well visits your website they can analyze it critically and unemotional, then highlight mistakes and suggest ways for you to improve your website's search engine optimization.
While purchasing a domain name may seem like the right way to go, many search engines do not recommend it. Some search engines have a long delay for adding new sites to their existing lists, and last thing you want is to delay getting new visitors. Using your existing website is more feasible, since the wait time for some engines is up to a full year.
Decide whether or not you want to use a link farm. Link farms are sites without content that just have thousands of links. This is generally seen as a negative thing. However, these do appear in search engines, and can help you rise in the ranks. It is your decision as to what is most important: rapport with other sites, or search engine rankings.
As mentioned at the start of this article, it's very important that you do not allow your efforts to go to waste. Learning the proper optimization tactics for the search engines out there is how your site or business goes from a simple start-up to being a legitimate and popular brand online. Use the tips you've just read to your advantage in SEO.$1*/ mo hosting! Get going with GoDaddy!