Sunday, October 31, 2010

"You have money waiting ... send your info to westernu.co.uk" and back.

Recently, I got an email from someone claiming to work for Western Union and asking me to send the usual information (first name, last name, date of birth and so on).

The trained eye will immediately recognize an attempt to grab some of my personal information. So, it must be removed.

"dig MX westernu.co.uk" tells me that the mailer is hosted by hotmail. So, I sent an email informing them that there is something phishy -- sorry fishy -- there.

Surprise! Here is the answer:


Thank you for reporting spam to the MSN Hotmail Support Team. This is an auto-generated response to inform you that we have received your submission. Please note that you will not receive a reply if you respond directly to this message.


Unfortunately, in order to process your request, Hotmail Support needs a valid MSN/Hotmail hosted account.


We can help you best when you forward the spam/abusive mail as an attachment to us. The attachment should have full headers / message routing information displayed. This means that the complete “From” address of the offending message should be displayed. If you need help to do this, please visit the following website:


http://safety.msn.com/articles/junkmail.armx


If you have deleted or no longer have the message, you can still resubmit your report by sending the name of the violating MSN/Hotmail hosted account and a description of your concerns. If your submission does not involve a third party, please include your own account name in the body of your message along with the description of your concerns so we can process your report.




For further instructions on how to submit spam and abusive emails to Hotmail, please visit:


http://postmaster.msn.com/cgi-bin/dasp/postmaster.asp?ContextNav=Guidelines


For more information about MSN Hotmail’s efforts and technologies used to fight spam and abusive e-mails please visit:


http://postmaster.msn.com/cgi-bin/dasp/postmaster.asp?ContextNav=FightJunkEmail

In summary, this is not an hotmail account, nothing will be done.

I deleted the offending email, so I have no way of controlling whether the account was disabled.

Monday, October 25, 2010

A clustered Samba Fileserver, Issue with packages on Fedora 13

In order to redo all the steps, I deleted and re-created my Fedora 13 virtual machines. However, when I arrive at installing the packages for clustering, the system can't complete the request, as it looks for older packages and failed to recognize the newer packages as valid.

I have open a ticket with Fedora's bugzilla: 646697

[20101026 - 8:30EST]

The cman maintainer, Fabio, and I narrowed down the issue to a nss-tools install problem: I run the x86_64 flavor of Fedora and when doing the yum install of the package, it tries to install i686 dependencies that are already installed in their x86_64 incarnation. For obvious reasons, this fails and the nss-tools package is not installed.

I had a quick look at the bug reports in Bugzilla but wasn't able to find anything related. I opened another bug report on which I'll work more on this as soon as I have the time. The new ticket is : 646807


[20101028 - 9:45EST]

"yum install nss-tools" now works correctly. Many thanks to the Fedora team!


J.

Sunday, October 24, 2010

Ubuntu 10.10 -- here I come!

As most of you know already, Ubuntu 10.10 "Maverick Meerkat" came out earlier this month. It was time for me to upgrade from my 10.04.


My laptop upgrade went fine, really fine. No issues.


On my workstation, the install turned wrong as my /boot partition was full: the installer failed to fully install the kernel and dropped me out of the process with a "fix the issue and re-run dpkg --configure --all". After issue the needed "apt-get remove", I ran the command. Which completed without doing a thing!

Ok, I have a copy of all my important stuff, so I decided to go for the reboot. Besides two "FATAL" messages as dependency files aren't to be found, the system was back online. Remained the traditional install of my nVidia drivers. And voila! Everything is working.


First impression: it's great, although it seems - and don't quote me on this, I don't have any scientific measurements - a bit slower than the 10.04. 


My mailer, Evolution, also reported an error "Unable to find mem.Inbox" the first time I started it, but not the following time, so that's ok. 


Another small problem: when I exit dosbox in fullscreen mode, the screen is not correctly refreshed. More an annoyance than a real issue.


Concerning the applications, nothing really changes as I upgraded. I'm right now in the process of importing all my pictures into Shotwell from F-Spot. 

That aside, it seems to be a nice release, and I'm looking forward to exploring it more.







Monday, October 11, 2010

Now reading "The design of design"

A clear and complete treaty on the processes and functions behind the design process itself. Written by an expert on design who worked, among others, on the S/360 architecture design, this book approaches many aspect of the design, such as methodologies, requirements and thoughts.

This is an interesting book for all involved in design, such as architects, system and software engineers and all whose job requires creating new systems.

Only shadow, the version I have has numerous typos and misspellings. Even if it doesn't make the text ambiguous or unreadable, it certainly doesn't add to the pleasure of reading the book.

Sunday, October 10, 2010

Google is testing a car that drives itself!

That's sweet: a car that drives itself in the streets.

Article on the NY Times

Saturday, October 9, 2010

A clustered Samba Fileserver, Part II - Replicated block device using DRBD

In this part, I will present the configuration of DRBD.

DRBD works by creating resources, that match a local device to a device on a remote computer. Logically, on both computer, the resource definition shall be identical, which doesn't mean the the actual physical device shall be the same.


Here is the resource created for this test:

resource r0 {
  on linuxnas01 {
    device    /dev/drbd1;
    disk      /dev/sdb;
    address   192.168.255.1:7789;
    meta-disk internal;
  }
  on linuxnas02 {
    device    /dev/drbd1;
    disk      /dev/sdb;
    address   192.168.255.2:7789;
    meta-disk internal;
  }
}
It creates a resource named r0, that exists on machines linuxnas01 and linuxnas02. On linuxnas01, the physical device associated with the resource is /dev/sdb. In this scenario, it's the same on linuxnas02. It makes the configuration easier to understand, but this is in no way mandatory.

First comment, this is for a resource in "primary-secondary" mode, which means that one node is consider to have a rw privilege, while the other is ro.

The line "meta-disk internal;" specifies that the drbd metadata (see [1] for a reference on these) are to be written on the physical device specified by the resource. This will have some importance when we will create the filesystem.

Also, it has an performance side to consider: each write operation will result in (at least) two actual accesses: one to write the sectors concerned, and the second to update the meta-data. If the goal is to put in place a filesystem that will need to have heavy performance, a better solution is to store these metadata on another physical device, for instance a high speed disk such as a flash drive or a 15K SAS disk.

On Fedora, don't forget to open the firewall. By default, only port 22/tcp is allowed, which prevent the DRBD connection to establish. As a result, one would see the nodes staying in the "Unknown" state. Also, you have to load the modules, either manually with "/etc/init.d/drbd start" or add them to the required rcX.d, with chkconfig or update-rc.d, depending again on your flavor.


Once the resource is configured, attached and up'd (see [2] for the chapter dealing with the configuration), it appears and starts to sync between the nodes.

[root@linuxnas01 ~]# drbd-overview
  1:r0  SyncSource Secondary/Secondary UpToDate/Inconsistent C r----
    [==>.................] sync'ed: 19.2% (1858588/2293468)K

udevadm can also be used to check that the device exists.

[root@linuxnas01 ~]# udevadm info --query=all --path=/devices/virtual/block/drbd1
P: /devices/virtual/block/drbd1
N: drbd1
W: 61
S: drbd/by-res/r0
S: drbd/by-disk/sdb
E: UDEV_LOG=3
E: DEVPATH=/devices/virtual/block/drbd1
E: MAJOR=147
E: MINOR=1
E: DEVNAME=/dev/drbd1
E: DEVTYPE=disk
E: SUBSYSTEM=block
E: RESOURCE=r0
E: DEVICE=drbd1
E: DISK=sdb
E: DEVLINKS=/dev/drbd/by-res/r0 /dev/drbd/by-disk/sdb

My excerpt shows Secondary/Secondary. To force a node to be "primary", let's use "drbdadm primary <resource>". Issued on the first node, this forces drbd to recognize that linuxnas01 is indeed the primary node.

At this point, I have a working resource on both machine. The next step is to create the filesystem on the primary node.


Bibliography

[1] DRBD web site, chapter 18, http://www.drbd.org/users-guide/ch-internals.html
[2] DRBD web site, chapter 5, http://www.drbd.org/users-guide/ch-configure.html

Tuesday, October 5, 2010

Congratulations to Andre Geim and Konstantin Novoselov

Dr. Geim and Dr. Novoselov were awarded the Nobel prize in Physics, 2010 for their works on graphene.

http://nobelprize.org/nobel_prizes/physics/laureates/2010/