Difference between registered memory and unbuffered memory

Unbuffered memory is also known as unregistered memory (or UDIMM). Buffered memory is also known as registered memory (or RDIMM). Unbuffered memory is memory where the memory controller module drives the memory directly, instead of using a store-and-forward system like registered memory. Buffered memory modules have built-in registers on their address and control lines.
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About CPU: The logical and physical cores

This post will demonstrate a detailed method of enumerating processors in a running linux server. Before delving into the topic, some terms should be defined: Physical Package: The physical package is a microprocessor. For each physical package, it plugs into a physical socket on a mainboard, and may contain one or more processor cores.
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Hpasmcli Usage Example on ProLiant DL380

Hpasmcli is short for HP System Health Application and Insight Management Agents, it’s a scriptable command line interface for interacting with the hpasm management daemons, which can be used to view / set / modify BIOS settings such as hyper-threading, boot sequence control, and UID LEDs. It can also be used to display hardware status. In […]
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Linux Disk Scheduler Benchmarking

[Dr. Peter Chubb, Project Research Officer – Gelato] Over the last six months, Google has sponsored Gelato to take a close look at the disk chedulers in Linux, particularly when combined with RAID. We benchmarked the four standard Linux disk schedulers using several different tools (see our wiki for full details) and lots of different […]
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Haystack new storage solution for billions of photos

This week Facebook should have completed its new photo storage system which is designed to reduce the social network’s reliance on expensive proprietary solutions from NetApp and Akamai. The new large blob storage system, named Haystack, is a custom-built file system solution for the over 850 million photos uploaded to facebook each month (500 GB […]
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