RRDtool - Rates, normalizing and consolidating Index Intro RRDtool stores rates during time intervals. A couple of different stages should be recognized: transform to a rate normalize the interval consolidate intervals into a larger one This does not get in your way, it is not doing bad things to your data. All stages apply for all input, no exceptions. If you use GAUGE, the input is already a rate, but it is still subject to normalization. Transform to a rate Everything is processed as a rate. There are several ways for RRDtool to get a rate from its input: GAUGE: keep it "as is". In each of these four cases, the result is a rate. This concludes step 1. About rate and time If you transfer something at 60 bytes per second during 1 second, you could transfer the same amount of data at 30 bytes per second during 2 seconds, or at 20 bytes per second during 3 seconds, or at 15 bytes per second during 4 seconds, et cetera. These numbers are all different yet they have one thing in common: rate multiplied by time is a constant. Normalize interval
Understanding NPIV and NPV Two technologies that seem to have come to the fore recently are NPIV (N_Port ID Virtualization) and NPV (N_Port Virtualization). Judging just by the names, you might think that these two technologies are the same thing. While they are related in some aspects and can be used in a complementary way, they are quite different. What I’d like to do in this post is help explain these two technologies, how they are different, and how they can be used. First, though, I need to cover some basics. N_Port: An N_Port is an end node port on the Fibre Channel fabric. There are other types of ports as well—NL_Port, FL_Port, G_Port, TE_Port—but for the purposes of this discussion these three will get us started. N_Port ID Virtualization (NPIV) Normally, an N_Port would have a single N_Port_ID associated with it; this N_Port_ID is a 24-bit address assigned by the Fibre Channel switch during the FLOGI process. So why might this functionality be useful? N_Port Virtualization Here’s another example.
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Cisco Virtualized Multi-Tenant Data Center, Version 1.1, Design and Deployment Guide - Cisco VMDC Design and Deployment [Support Table Of Contents Cisco VMDC Design and Deployment Compute Virtualization vSphere 4.0 Virtual Center Server Nexus 1000V Switch Virtual Ethernet Module Virtual Supervisor Module Control and Packet VLANs Port Profiles System VLANs Unified Computing System Design Physical Hardware Layout UCS Cluster UCS Chassis Server Blades Cisco UCS 6100 Series Fabric Interconnect Cisco UCS 2104 Fabric Extender Overall Network Architecture Ethernet Switching Mode N-Port Virtualization Mode LAN Design SAN Design UCS Manager Administration Role Based Access Control Server IP KVM Availability Syslog Setup Servers vNIC Configuration vHBA Configuration UCS Best Practice Resources Data Center Layer 2 Design Access, Distribution, Core, and Services Layer Design VLAN Design STP Design STP Logical Topology Nexus 1000V Layer 2 Design Nexus 7000 Layer 2 Design Virtual Port Channel Design Virtual Switching System Layer 2 Design VSS Operation VSS by Architecture Layer VSS Best Practices and Caveats EtherChannel Load Balancing Data Center Layer 3 Design Gold On
Remote Ubuntu Dapper Drake Install – nanoRAILS Don’t try this at home! Well, actually, there are 2 ways you can look at it. Only attempt a remote install if it is absolutely necessary and there are no other practical ways of doing the OS install. On the other hand, that’s exactly what you want to do. Anyway, now you’ve been warned and if you are still reading, here’s the challenge I was facing. I had a machine (not the fastest, but a machine) with an old version of Linux. So I did some research, and using Google, it is fairly obvious that the article by Erik Jacobson that you should read first if you want to attempt any remote install of debian is the authority on the subject. I could not find anything on Ubuntu, however. So I read the HOW-TO carefully, a few times to let it sink in, and got started on my Ubuntu Dapper Drake (6.06) remote install. Here’s what I did. I first followed the procedure in the HOW-TO to install debian. I used the rpm from [ mke2fs /dev/hda6
Fabric Login Process Copyright ©2009 EMC Corporation. Do not Copy -All Rights Reserved. San Storage Protocols ©2009 EMC Corporation. SAN Storage Protocols OverviewSAN Storage Protocols Overview Copyright ©2009 EMC Corporation. RRDtool - Some tutorials by Alex van den Bogaerdt block access & file access Storage often doesn't get the attention it deserves, which can turn out to be a costly oversight. George Ou provides this overview to get you up to speed on the various storage subsystems and the devices and technologies that support them. This article is also available as a PDF download. Oftentimes, storage isn't given enough attention in system architecture, but it can make or break the service level agreement (SLA) for your application response times. Storage is a huge topic, but this article will give you a high-level look at how it all fits together. DAS, SAN, and NAS storage subsystems Direct attached storage (DAS), storage area network (SAN), and network attached storage (NAS) are the three basic types of storage. DAS -- direct attached storage DAS is the most basic storage subsystem that provides block-level storage, and it's the building block for SAN and NAS. Storage devices used to build a DAS storage subsystem SAN -- Storage area network SAN technologies
MRTG - MRTG Documentation mrtg What is MRTG ? mrtg-unix-guide The MRTG 2.17.4 Linux/Unix Installation Guide mrtg-nt-guide The MRTG 2.17.4 Windows Installation Guide mrtg-nw-guide MRTG for NetWare mrtg-reference MRTG 2.17.4 configuration reference cfgmaker Creates mrtg.cfg files (for mrtg-2.17.4) indexmaker Creates index files for mrtg web sites (mrtg-2.17.4) mrtg-contrib Contribution Guidelines for MRTG mrtg-faq How to get help if you have problems with MRTG mrtg-ipv6 IPv6 support in MRTG mrtg-logfile description of the mrtg-2 logfile format mrtg-mibhelp A Table of some interesting OIDs mrtg-rrd How to use RRDtool with MRTG mrtg-webserver hints for web server configuration mrtg-traffic-sum Builds monthly traffic summary from mrtg log files