Monitor your mdadm RAID Arrays and get E-mail Alerts

You can be using a piece of software for some time and not know of one of it most useful functions. In my Desktop computer I use a software RAID1 to protect me against any data loss. RAID is where you join two or, more Hard Drives into a mirrored array. This basically means that if a drives fails, you don't lose all your data. If you also mirror the Operating system, it results in no or, little downtime.

I have two identically sized SSD (Solid State Drives) and two identically sized hard drives. The SSDs have two identically sized partitions for the Operating System and Boot. I‘d be gutted to be without my PC for too long following a failure.

This article is not about setting up or, configuring my chosen mdadm software raid but, how to get automated alerts if there is degradation. A warning before potential drive failure. I only have found out about getting email alerts recently and until now, manually ran cat /proc/mdstat from time to time.

md0 is my Boot and OS.
md1 is my /home.

media:~$ cat /proc/mdstat
Personalities : [raid1] [linear] [multipath] [raid0] [raid6] [raid5] [raid4] [raid10]
md1 : active raid1 sdb5[3] sdd5[2]
1952405312 blocks super 1.2 [2/2] [UU]

md0 : active raid1 sda1[0]
58091392 blocks super 1.2 [2/1] [UU]

unused devices:

Prerequisites

Before we get started:

• You have to have an SMTP server that can send the emails from your workstation, to the recipient (i.e. your corporate exchange or Gmail).
• You have the credentials for a user that is able to send Email on that server (i.e. a mailbox or a Gmail account).

There are a few simple SMTP servers out there. The ssmtp (Simple S.M.T.P) package works well. There are better setup articles but we can quickly set it up.

To install the ssmtp (Simple S.M.T.P) package, use the following command:

sudo apt-get install ssmtp

Using your favourite editor, edit the configuration file:

sudo nano /etc/ssmtp/ssmtp.conf

Edit the following lines. The number after the colon, is the port number used to connect to your email providers SMTP service.

root=username@gmail.com
mailhub=smtp.gmail.com:587
hostname=username@gmail.com
UseSTARTTLS=YES
AuthUser=username
AuthPass=password
FromLineOverride=yes

In order to make the default (root) “from” field be the server name, edit the /etc/ssmtp/revaliases file:

root:machine-name@some-domain.com:smtp.gmail.com

Test the ssmtp setup by sending an Email:

echo "Test message using ssmtp" | sudo ssmtp -vvv your-email@some-domain.com

Configure mdadm

sudo nano /etc/mdadm/mdadm.conf

Just find and edit the following line:

MAILADDR username@gmail.com

Rather than just restart the service, it is best to restart the PC.

You can do a quick test that it is now working

sudo mdadm --monitor --scan --test -1

Buying goods via the internet for a offspring who are in a foreign land

Our son was in Tokyo 2017 to 2018, in his third year of Japanese Studies at Seijo University and we found out how expensive / difficult it was to send gifts to him.  I hope by blogging this, other families will see what options are open to them, no matter the country.

Buying gifts in your country and then sending by international courier is not cheap.  For Christmas we boxed up gifts.  It weighed under 6 kgs but, was so expensive.

There are a lot of ex-pats through out the world so, we expected there to be online site within a country where, you could have UK food and drink delivered.  What we found in fact was that there are UK based online sites but, they were sending from the UK.  So again, expensive P&P!

Easter was coming up so, we wanted to send a few of his favourite foods.  We did do a search of Tokyo based online stores and indeed found some selling UK/western product.  However, when it came to purchasing from the Shopping Cart, we could couldn't set a Tokyo delivery address with a different invoice address.  The invoice address is important as it is used for your card purchase.  We just couldn't set a UK invoice (payment) address.

Finely, I tried www.amazon.jp for Amazon Japan.  You could search for desired destination country in this way.  I did find that I had to create a new Amazon account because, I couldn't log in with my UK account credentials.  I cannot read Japanese so then, before I continued, I set the language to English.

From Japanese


To English

I then set up the security so that the account could only be logged in to with two-factor authentication.  What this means is that, you have your normal username and password but, a text or voice message is sent to your desired mobile / landline telephone number.  The system sends (at no cost) a six-digit code for you to type in.

You then are able to browse the website with item descriptions, Shopping Cart and Payment steps in English. One more thing which, was very important for Japan is, to get the FULL address from the recipient. It was over wise difficult to complete the delivery part of the purchase without the district and postcode entered in the correct order.

I hope this brief article will be of use to someone.

My TV's HDMI port/s no longer work! Do I throw the TV away?

No! I am not a fan of just throwing something away that, could be resurrected rather than, add to the Worlds WEEE  electronic waste. Replacing the TV could cost hundreds of pounds when, devices exist that cost between £20 and £30 and could give you full functionality of your TV again, bypassing the faulty HDMI video control chip.

I am aiming this article to the everyday TV user not, the electronic geek.  A 'plug n play' solution.  However, some of you might have researched and seen that you can fix electronic devices by, ' using a Hairdryer / Heat Gun on the xxxx chip' or, ' baking the xxxx circuit board in an Oven'.  Let me dissuade you from this please. The resulted 'fix' seldom lasts long and could even fail and you end up with a useless (dead) TV.

The technically savvy would know that you can buy replacement (fully working) circuit boards for around £30 but, I am not aiming this article at those people.  They don't need my help. Also, in this disposable World, it can be hard to find such replacements for an old TV.  For instance, I could not get a replacement board for the LG LCD TV I have that, was manufactured six years ago.  A major grumble of mine and at the time of writing, the EU are proposing law that forces manufacturers to make electronic devices last longer and be more repairable.

Jumping straight to the answer...
Look at the back of your TV and if you see three sockets that say, 'Component Video In' then, buying the following will get you back up and going:-
1 x HDMI to YPbPr RGB Component Converter
1 x Component Video cable
1 x RCA Stereo audio cable

Component YPbPr video will still give you full HD (1080p) quality.  The Component video lead has separate 'Red', 'Green' and 'Blue' connections that carry the video from the converter, to your TVs 'Component Video In' connections.  The RCA Stereo audio cable carries the audio left and right channels from the converter, to your TVs Component audio connections.

If you think that this is just too many unsightly cables, the converter device is small enough to be hidden from view. Even use Velcro to stick it behind the back of your TV and use short cables. No one will notice.

If you don't have an AV Receiver / Amplifier and want to connect multiple HDMI devices to my above solution then you will need to also look at getting a HDMI Switch device. There are many available and can allow anywhere between three and five devices to be connect to a single HDMI output that, would then be connected to the converter mentioned above.

My story in depth

A work colleague gave me an LG 47 inch LED TV featuring 100Hz, 1080p HD and Freeview HD.  He was throwing it away as, the HDMI ports had stopped working.  He just went out and bought a new TV.  Yes, he was probably better paid than me! Thanks Scott!

All my AV devices connected to my Onkyo AV Receiver which has six HDMI inputs and one HDMI output which, I would normally have connected to my TV.  So, I would normally have only one HDMI lead connected to the TV.

For completeness, connected to my AV receiver are:-
Blu-ray player, FreeSat PVR and a DIY Kodi Media Center that I built from an old PC.

Sadly, I could not get a replacement circuit board for the TV so, I looked at other options.  It just bugs me when, an otherwise good device is crippled by the poor manufacture of a single semiconductor chip.

Most modern TVs come with a plethora of connections.  If you look at the back of modern TVs it can be quite daunting.  HDMI is the latest connection that gives you a single socket to connect your full HD (1080p) devices to your TV.  It is by far the most convenient way to plug an AV (Audio – Video) device in to a TV.  Thus, most device manuals don't go in to detail about the 'other' connections (sockets) on your TV.

Before HDMI, Component video (YPBPR) was an alternative and can be found on most A/V Receiver, Blu-ray players, DVD players and LCD video projectors.

Update
After five months use, my Porta died. I contacted the supplier who, were the manufacturer and they sent a replacement. However, it was only the mains adapter that failed. So, I ordered a 5Vdc 3Amp mains adaptor and got the original going again.

Appendix
Below is what I bought and is an example only.  There are other brands out there.
HDMI to YPbPr RGB Component Converter
Component Video RGB YUV 3 Phonos To 3 Phono Cable Lead 50cm 0.5m
Twin RCA Phono to RCA Phono male audio lead 1.5mtr