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Displaying posts with tag: Hardware (reset)
Amiga 500 Restoration: A501 Memory Expansion

The previous posts were mostly about cosmetics. This one is more technical, dealing with the repair and some preventative maintenance of the A501 memory expansion card. If you are curious to learn more about the retrobrighting of the computer’s case, don’t worry — I’ll get back to that at a later time.

This is the third post in a series about restoring an Amiga 500 back to its former glory. Here are all of them so far. I’ll try to remember to update this in all related entry.

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20-30% Performance Hit from the Spectre Bug Fix on Ubuntu

In this blog post, we’ll look at the performance hit from the Spectre bug fix on Ubuntu.

Recently we measured the performance penalty from the Meltdown fix on Ubuntu servers. It turned out to be negligible.

Today, Ubuntu made a Spectre bug fix on Ubuntu available, shipped in kernel 4.4.0-112. As with the Meltdown fix, we measured the effect of this update. Unfortunately, we observed a major performance penalty on MySQL workloads with this new kernel.

Our benchmark used the following:


  • CPU:
    • 2 x Intel(R) Xeon(R) CPU E5-2680 v3 @ 2.50GHz (Codename Haswell)
    • /proc/cpuinfo has 48 …
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Amiga 500 Restoration: Retrobrighting I

In part one I described how I got and disassembled an Amiga 500 for a thorough cleaning. This part is about my first attempts to restore the grey/beige color the case had originally had, but over time had turned it an ugly yellow.

This is the second post in a series about restoring an Amiga 500 back to its former glory. Here are all of them so far. I’ll try to remember to update this in all related entry.

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Meltdown and Spectre: CPU Security Vulnerabilities

In this blog post, we examine the recent revelations about CPU security vulnerabilities.

The beginning of the new year also brings to light fresh and new CPU security vulnerabilities. Today’s big offenders originate on the hardware side – more specifically, the CPU. The reported hardware kernel bugs allow for direct access to data held in the computer/server’s memory, which in turn might leak sensitive data. Some of the most popular CPUs affected by these bugs are Intel, AMD and ARM.

The most important thing to know is that this vulnerability is not exploitable remotely, and requires that someone execute the malicious code locally. However, take extra precaution when running in virtualized environments (see below for more information).

A full overview (including a technical, in-depth …

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Amiga 500 Restoration

About 6 weeks ago I got the somewhat crazy idea to — just for fun — play some Amiga games. At first, my plan was to set up a Raspberry Pi 3 with an Amiga emulator, after stumbling across Dan Wood’s YouTube channel. Even though I even have a Pi 3 lying around unused at the moment, seeing Dan holding that Amiga 500 in his hands at the beginning of the video, I got all nostalgic and decided I could at least do a quick ebay search to see how much they go for these days.

Turns out, I could get my hands on one, including a memory expansion card, mouse and power brick (and a brick it is!) for  just 60€. Turns out, I would end up spending quite a bit more in the end, but still it was (and still is) a fun experience.

The whole story is probably way too long for a single post, so I may end up splitting this into at least two parts, but I feel it is …

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JKDB PLATFORM – our company’s data management platform

In this post, we introduce backup-restore module,focus on automatic backup and restore in a huge MySQL database environment.


Using NVMe Command Line Tools to Check NVMe Flash Health

In this blog post, I’ll look at the types of NVMe flash health information you can get from using the NVMe command line tools.

Checking SATA-based drive health is easy. Whether it’s an SSD or older spinning drive, you can use the


 command to get a wealth of information about the device’s performance and health. As an example:

root@blinky:/var/lib/mysql# smartctl -A /dev/sda
smartctl 6.5 2016-01-24 r4214 [x86_64-linux-4.4.0-62-generic] (local build)
Copyright (C) 2002-16, Bruce Allen, Christian Franke,
SMART Attributes Data Structure revision number: 16
Vendor Specific SMART Attributes with Thresholds:
 1 Raw_Read_Error_Rate     0x002f   100   100   000 …
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we use tcpcopy to make real traffic on our core systems. Many problems will be found in advance if we enlarge queries several times.


Infiniflash Benchmark

Sandisk (FusionIO) and Nexenta are working together to build this SDS solution.

Infiniflash is a very large SDS production, which manages for very large DW system who requires large storage space and also high IOPS.

We test infiniflash system ,read this Infiniflash_benchmark

MySQL distributed message system

Based on messages, we create mysql replication platforms , using async message to build strong distributed subscription system.

read this PDF :

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