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Displaying posts with tag: Linux (reset)
Some LSI 9211-8i issues on Windows and Linux
tl;dr:
Make sure you flash an LSI-9211 to IT firmware rev#14 to get it to work 
with Linux and SSD trim.  You may have to downgrade from newer firmware
to older firmware to get the card to work.



Finding a SATA III controller with more than one PCI-e lane
After a recent hardware issue I decided to upgrade my computer to use new Intel 520 120MB SSD drives in RAID for improved performance.  The motherboard I use (an ASUS Rampage III extreme) has a Marvel SATA III controller with two ports, but I discovered that it is connected via only a single PCI-e lane (each lane can do at most 400MB/sec*).  This means that it can't effectively support even a single Intel 520 because one device can saturate the SATA III bus (An Intel 520 is rated at up to 550MB/sec sequential write).

So I went on a quest for a new SATA 3 controller.   To Frys! I exclaimed.  But unfortunately, all the PCI-e 2.x SATA III …

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#DBHangops for 5/15/13 — Filesystems, monitoring, settings, Oh my!

Here’s the recording!

Heyo!

Now that we’ve gone through the Percona Live MySQL Conference and Expo review and had an amazing turnout to talk about it, it’s time to open up the discussion around things that DBAs want to talk about and need to be conscientious of. Join us on Wednesday at 12:00pm PDT (19:00 GMT) to take part in the discussion and share your knowledge and experience with the following topics:

  • Filesystems and MySQL — Which do you use and why?
    • Do you handle I/O alignment? How do you do it?
    • Scheduler changes?
  • Nagios checks! — Any new checks you’ve added recently?
  • The worst settings in MySQL that you always change
  • What are the most important variables to you, and what do you set them to?
  • What will be important variables in 5.6 that …
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Storage caching options in Linux 3.9 kernel

dm-cache is (albeit still classified “experimental”) is in the just released Linux 3.9 kernel. It deals with generic block devices and uses the device mapper framework. While there have been a few other similar tools flying around, since this one has been adopted into the kernel it looks like this will be the one that you’ll be seeing the most in to the future. It saves sysadmins the hassle of compiling extra stuff for a system.

A typical use is for an SSD to cache a HDD. Similar to a battery backed RAID controller, the objective is to insulate the application from latency caused by the mechanical device, the most laggy part of which is seek time (measured in milliseconds). Giventhe  relatively high storage capacity of an SSD (in the hundreds of GBs), this allows you to mostly disregard the mechanical latency for writes and that’s very useful for database systems such as MariaDB.

That covers writes (for the moment), but …

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2013 MySQL Conference and Expo — a #DBHangOps Review

Hey everybody!

The Percona Live MySQL Conference and Expo just wrapped up last week and we’re looking to get some conference in review talk from everyone! Talk about your favorite sessions, new things you learned, and your overall opinion of the conference!

Hop online Wednesday at 12:00pm PDT (19:00 GMT) to join the discussion and share your experience from the 2013 Percona Live: MySQL Conference and Expo.

Be sure to watch this twitter search or this blog post get a link for the google hangout tomorrow!

Some talks that were specifically called out:

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Connecting your Linux to a Cisco AnyConnect (SSL) – part 3

Hi there !

 

This is the final part of using openconnect  - You can check the older ones below:

http://www.heitorlessa.com/connecting-your-linux-to-a-cisco-anyconnect-ssl-part-1/

http://www.heitorlessa.com/connecting-your-linux-to-a-cisco-anyconnect-ssl-part-2/

 

As mentioned previously, we will be covering here:

  • How to create a script to monitor such VPN using ICMP, and restart that VPN if it is down

 

I would say, this is very straight forward and does not require much knowledge, so we are going to follow the same procedure as part 2 – Show the script in parts and then a …

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Connecting your Linux to a Cisco AnyConnect (SSL) – Part 2

Hey you!

As said in the part 1 of this article, I will be covering here:

  • How to create a openconnect init script

So, concerning the init script I will be posting parts of the script first, and then will put a link for download at the end.

First of all, we need the shebang (#!/bin/bash) and then global variables that will be used along the script:

# Path variables
PATH="/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin"

# VPN Variables
IFACE="sslvpn"
VPN_USER="vpn_user"
VPN_HOST="sslvpn.yourdomain.com"
VPN_PASS="vpn_password"
PID="/var/run/openconnect.pid"
TEMP_LOG="/tmp/status.txt"
INFO="Usage: $(basename "$0") (start|stop|status|restart)"

You can also define most of these options in a …

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Check (Rough) Progress of Your CSV Import to MySQL

If you are importing large CSV or SQL dumps to MySQL, chances are you were looking for ways to see how far the import has gone. If you know how many rows there are from the file being imported, you can do a SELECT COUNT(*) but that would take sometime for the query to finish especially on really big imports.

Using lsof, you can monitor the current file offset to which a process is reading from using the -o option. Knowing the size of the file and some snapshots of the offset, you can get a somewhat rough idea of how fast the import goes. Note though that this is only file-read-pace not actual import speed as MySQL import can vary depending on a number of conditions i.e. table growth, secondary indexes, etc.

Let’s say I am importing a 1.1G CSV file into a table.

[revin@forge msb_5_5_300]$ ls -al /wok/dta/samples/ft_history.csv 
-rw-rw-r--. 1 revin revin 1075456654 Nov 8 23:25 /wok/dta/samples/ft_history.csv …
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How To Run Your Own Web SMS Portal With PointSMS

How To Run Your Own Web SMS Portal With PointSMS

This tutorial will show you how you can set up an SMS web site on CentOS using PointSMS.

#DBHangOps 3/27/13!

Hi everyone!

Here’s a video of this week’s #DBHangOps:

March 27th at 12:00pm PDT (19:00 GMT) is when the next #DBHangOps is gonna go down. Check out the twitter search and hop on the google hangout to contribute some discussion! This week’s topics are:

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How to fix the Percona repo failure when installing Percona Toolkit

Here’s a solution to the not-so-long-standing issue of the Percona yum repo being broken for the CentOS 6 x86_64 version of the Percona-toolkit package. The repo listing is reporting an older version of the RPM which is not available on the site, so to fix this you just have to download the newer file and tell yum to add it locally. The side benefit is that you can use Yum to manage the RPM without adding the Percona repo, since the default settings for their repo could/have/had caused conflicts with Base Repo versions of MySQL packages; the Percona repo instructions set ‘enabled=1′ — not a great idea if you’re not setup to use the Yum priorities method of repo weighting.

So, if you see this after installing the repo via the instructions on their site:
Downloading Packages:
http://repo.percona.com/centos/6/os/x86_64/percona-toolkit-2.1.9-1.noarch.rpm: [Errno 14] PYCURL ERROR 22 – “The requested URL returned …

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