Monday, 30 January 2017

The unintentional DoS

DoS - Denial of Service

Over the weekend it was very hot here - 39C over both days and air conditioning was being pushed pretty hard. My team and I had two unrelated, but linked situations evolve that could have hit us with a DoS. You see, we have a network attached storage device (NAS) that had a fan failure. While this NAS has redundant fans in it, one wasn't enough to keep the temperatures under the 55C warning threshold. So it started to complain....

Over the course of the 48 hour weekend, this NAS sent out over three and a half thousand emails! 3500+ emails! All to our logging email addresses, which then sent it out to the members of the team. 5 team members, 3500+ emails.... 17,500 emails being sent and received. That's a lot email in a short time. Most email servers will handle that and ours certainly did. Fortunately too we use G-Suite (Google Apps new fancy name) and so the volume of mail wasn't an issue.

What became an issue though - and this did have an effect on our phones and mobile devices picking up email - was that another network device - a disaster recovery server - also suffered heat stress from failed air conditioning. A sparky had unplugged our monitoring device to charge his tools and hadn't plugged it back in, so we had no idea what was happening (this was Sunday afternoon). When the A/C failed, the server turned off and the replication servers started to complain - four of them, every 30 seconds.... Over 12 hours those servers alerted our logging email address over 5,000 coming in and going back out - another 25,000 emails hitting phones plus the other emails as well.

Having had the discussion with clients about hosted email solutions versus onsite solutions, there are definite advantages to having huge servers managing your email. So if you don't have a cloud based solution, how can you mitigate this risk?

Defence in depth is a great place to start. Organise to get a mail exchanger - MXGuardDog or something similar. Westnet used to do one too. Get your MX records updated to punch mail through that. These then relay to av-relay.domainname.com. Configure your firewall to only accept emails from the IPs at MXGuardDog (for example) and drop everything else (or at least grey list it so it gets dropped and the sending server can try other MX records).

This way you can temporarily control the flow without having your ADSL or NBN connection getting flogged to death.

Configure your internal mailer to hold emails for this kind of thing - to recognise a flood of email and trickle it out where possible. The risk is that legitimate email (which these emails both are and aren't) will get lost in the flow. It's better than having your upload link fully saturated though (which will kill all internet connectivity).

DoS are bad. DDoS are worse. Let's try to avoid doing it to ourselves!

Wednesday, 25 January 2017

3 Word Processors compared - Microsoft Word, Apple Pages and Google Docs

In the course of work and university I've been jumping a bit between Word, Pages and Docs for various reasons. I thought it might be useful to compare them. Let's start.

Price


  • Google Docs is included either in a free Gmail account or G-Suite. Its available for free on your mobile device with native apps on iOS and Android
  • Pages is $30.99 and can be found in the Apple Store. It's included in iOS on the iPhone or iPad
  • Word is part of the Microsoft Office Suite. The cheapest of which is Office365 Personal (for Mac) which is $89 inc GST per year (See the Microsoft Office pricing page here). Includes a licence for a single mobile device
On price Docs is the obvious winner. Free to get access to and solid support on mobile devices. 

Usability

All three of these applications are very useable - but which one is *most* usable? Google Docs is a clean, uncluttered interface with relatively few options available:


Simple and uncluttered with everything there and looking like every single other word processor through history.

Pages has a different take on it, and one that can be a bit confusing to begin with.

The sidebar gets added into the mix, and many controls are moved out of the top menu and into here. I don't mind this personally, but I do find on the MacBook that I dislike losing the screen real estate to this menu. It is functional though.

Word has the infamous "ribbon". This is the Office365 version of it:

Since Microsoft changed the menu titles back to being in regular capitals / lower case, the readability of these menus has improved immensely. I remember when the ribbon came out and people loathed it. It just is now and I find it to be quite useful. The drawback for me with Microsoft Word is the sheer number of options available. We are spoiled for choice, control and capabilities and it can be overwhelming at times.

The usability winner is a totally individual choice and I leave it up to you to decide. Personally I like Pages but I'm ok getting around all three.

Functionality

This is a big one to consider. Word has clearly got it all (and most users will touch about 10% of it's capabilities day to day). Pages is likewise heavy on features and Docs comes in last, with its smaller range of functions. I think because Docs is web based then it was forced into more simplistic functionality and Google had to really choose the key word processing capabilities to include.

There is one function that stands Word out from Pages though in these heavy hitters. The ability to have a section in landscape, while the rest of the document is in portrait is not available in Pages (that I could find). Now most people probably won't care about this overly, but for me, if I'm inserting a large landscape graphic or big table it is critical and stupid Pages won't do it. Very frustrating. I've never really tried it in Docs, but a 3 second Google search shows it's not possible. Word wins for this!

All three offerings have Table of Content, header, footer, page numbers, insert stuff blah blah - you get the drift. All the basics and day-to-day stuff is there, and its only the more advanced activities where they are differentiated.

Aesthetics

Which one is the prettiest? A very subjective question of course. It should be noted that Apple have spent a lot of time on fonts and appearance, but so have Google and Microsoft (they just aren't as talked about). This is up to you - but I rank them Pages, Docs, and Word. Word is a bit busy for me - lots going on and when I'm working on an assignment or report I need clarity. Docs is very good for this, but something about the Pages appearance appeals to me.

Things to note about the different applications

Pages is Apple centric - don't bother looking for it on anything that doesn't have the Apple logo. That being said, it integrates very well with iCloud and syncs to your mobile device quite happily. 

Word is starting to become ubiquitous everywhere - Microsoft have released Office365 in a web browser, it's installable and available as an app on most mobile devices. The experience is the same across them all and really is improving.

Google Docs is maturing constantly and more features are being added frequently. For collaboration it is King. See updates and writing by other people in almost real time and easily give various levels of access to documents. For working with colleagues Docs is the best - Pages and Word are not in the same realm.

Tuesday, 10 January 2017

osTicket and OTRS - a comparison

While I have been a fan of OTRS for many years and like the interface, reporting and usability of it, I recently chanced across osTicket (from the TV series Mr Robot). It looked interesting and a client I have wants an internal ticket management system (they had also seen it). After a bit of to and fro, they agreed to some research time and I set up osTicket.

My usual server OS is Ubuntu's latest LTS. In this case, 16.04LTS. The problem is, it ships with PHP7, and osTicket doesn't play nicely with that. There is a good tutorial over on Chubbable that's worth checking out: https://chubbable.com/osticket-install-guide/2#ubuntu-based

Have a look at that if you want to install it - it's pretty straightforward.

So my impression of osTicket is that its pretty good. The interface is reasonable intuitive and I've set it up at home to manage the stuff I'm going (but mostly just to play with it). There is a client interface and an agent interface. The Agent interface gives you access to tickets and tasks. Tickets are the top level action, tasks are a part of tickets. In this way, some basic project management can be applied. Here are a few different views that are available:

osTicket Dashboard

osTicket Task view - got some work to do on NFS No Limits!

osTicket Tickets


You can see in the Tickets there is an NFS No Limits ticket. Under the tasks panel, you can see I've broken this down further into the things I need to do with that Ticket. I imagine with multiple agents, the tasks could be spread around.

So why not migrate to osTicket? The ability to capture time in osTicket seems to be hideously complicated to implement. Perhaps I need to do more research into that, but in OTRS its pretty straightforward. For a company just interested in getting things done, then the time capture isn't so important, but for us - its a big part of the job being completed. Reporting is still something I need to investigate. The reporting in OTRS is great (once you get your head around it) so I'll be interested to play with osTicket a bit more and see how it goes. Stay tuned for more updates...!

2017 - a new year and new challenges in IT ahead!

Welcome back.

We've got a lot to do this year - the number of attacks is increasing again, Microsoft's new update policy will have it's full effect on the computing ecosystem and Linux will be a prominent part of this blog. Lots happening indeed....

We're at the 10th day of January and I've already had servers lose their Kerberos connectivity with active directory, our first cryptolocker infection and so much more.... I need a lot more coffee to deal with this pish.

Stay tuned - I'm hoping to get my hands on some new tech and describe, some old tech and revive it, and just generally putter around for your amusement.

So far I have learned this:
  • MacBook Pro's (2012) can and do lose their wifi capability - I think the on-board adapter and finding one that works with a Mac can be tricky. 
  • MacBook Air's have a battery problem - they turn off and won't turn back on until you remove the battery (an annoying exercise)
Plus all the stuff on fixing Kerberos etc which will be the subject of a post down the track.

Let's get to it.

Monday, 19 December 2016

Notes for installing Ubuntu 16.04.1 LTS on Hyper-V

The last couple of servers I've installed on Hyper-V with Ubuntu 16.04.1 LTS with 4.4 kernels have annoyingly hung shortly after setup.

Here is an excerpt of the errors:

info task rs main q reg 1162 blocked for more than 120 seconds not tainted

 This is a very inconvenient feature and I think I've nailed it. From Microsoft's site they have details on adding bits to your install that add functionality and (hopefully) will help avoid this issue.

The Microsoft page is here: https://technet.microsoft.com/en-us/windows-server-docs/compute/hyper-v/supported-ubuntu-virtual-machines-on-hyper-v?f=255&MSPPError=-2147217396

And the guts of it is to do the following (with 16.04):

  • # apt-get update
  • # apt-get install linux-virtual-lts-xenial
  • # apt-get install linux-tools-virtual-lts-xenial linux-cloud-tools-virtual-lts-xenial
and then reboot. It should fix it.

 The error was something like Kernel not tainted or similar. So far it's working.

Update 2016-12-22

It stopped working. Super annoying. Have tried from this site: https://www.blackmoreops.com/2014/09/22/linux-kernel-panic-issue-fix-hung_task_timeout_secs-blocked-120-seconds-problem/

See how that goes.

Have also done the stuff on this site: https://oitibs.com/hyper-v-lis-on-ubuntu-16/

Will see how that goes.

Saturday, 26 November 2016

Dell Inspiron 11 3162 Review

I bought this little 11" laptop off Dell's site after poking around and thinking it would be nice to have a little laptop again. I really missed my MacBook Air after I sold it - silly move that - so I thought why not consider this one? It's specs are underwhelming:

  • Celeron N3050 processor
  • 4GB of RAM
  • 32GB eMMC HDD
  • Bluetooth version 4
  • WiFi - 802.11ac+
For what it is, it performs quite well. It's crippled though. In fact - so crippled I couldn't get the thing to start a week ago. It would try to boot into Windows 10 and just hang and hang and hang - you get the drift. I let the power completely drain then tried again. Repair windows install was the next question.... grr. After completing this it booted. That's the only problem I've had with it.

I have had the chance to use it for a couple of presentations. The built in HDMI interface is amazingly handy and the Dell drivers work well for the system, allowing for quick and painless swaps between things. It also gets 8 hours out of the battery which is very impressive indeed. I've tested this twice, and after a full day of work it still had some go in it. 

The ergonomics aren't too bad - I find the keyboard a tad small. But to give you perspective, I'm typing this on a wireless Mac keyboard and I find that a tad small too. I'm most comfortable on an ergonomic keyboard, the Microsoft Sculpt is the current choice of weapons for that. The mousepad is responsive and I find it to work quite well.

All up, this little laptop was about $275 - this model was $300+ at JB HiFi. It's worth checking the manufacturer's site for these better deals. For the equivalent money at JB I'd have only gotten 2GB of RAM. That extra RAM can make an enormous difference! Can't remember if the disk was bigger was or not, but there is an SD card slot so I've already slammed a 64GB disk into that. Combined with network storage and the high speed wifi, I'm set to go.

I think this machine is pretty good. I've got a real dislike for Windows 10 and the way privacy and updates are being handled, but I'll leave that for another post. I'm going to investigate putting Linux on this machine. I think it'll go really well with it.

For a cheap laptop, it's got some solid specs and it's reasonably good to use. 

Friday, 11 November 2016

Dell T110 Server - older tech still doing the yards

The last time I was out in Coober Pedy, I saw a lot of Toyotas running around. Landcruisers mostly - a great vehicle and out in the Red Centre with some pretty harsh conditions, they were the vehicle of choice. Solid, reliable, amazingly well built. It's a bit like the older Dell servers still kicking around.

To my case in point - the Dell T110 Server. These servers, brand new, with a Xeon Processor, 4GB of RAM and a 250GB HDD were around $1400. We got several cheap, added RAM, disk and an OS and sold them to customers. The basic spec was pretty sound:
  • Intel(R) Xeon(R) CPU X3430 @ 2.40GHz 
  • 4GB of RAM (maximum 16)
  • Dell PERC S100 onboard RAID (fake RAID but still OK)
  • space for 4 disks
  • tower configuration
 About 18 months ago I was given one of these servers by a grateful client after a particularly painful weekend migrating one server to another. After thinking about it for a bit, and knowing the S100 RAID card is Windows only (Linux won't see the arrays, just the disks - use AHCP if you're using Linux), I decided to pop Windows 2012 Server on and run a bit of the Hyper-V action for shits and giggles. In order to do this and to solve a tricky customer problem, I upgraded the server a little bit.

I added two 250GB SSD disks and made them the primary array, with the two 250GB HDDs as a data array. I installed Windows 2012, set up Hyper-V and then built a 2008R2 server as a VM. I also added more RAM to max it out at 16GB. Now, the 2008R2 server boots up in under 20 seconds! It is so quick and as I was using it to try to repair a broken SharePoint (see my previous post on this) I was very happy to have a machine that would restart in the blink (almost) of an eye.

Fast forward to about 3 months ago, I ditch the 250GB HDDs out of it and upgrade them to 2TB drives giving me a data array of 1.8TB for stuff. I've used the machine to create (and destroy) about 20 different VMs for testing and it has been reliable and solid for all the time. Suffice to say I'm very happy with it.

I was puttering around on eBay about 3 weeks ago and saw one of these for sale for $150! I grabbed it, as quick as possible. It turned up with the base spec. Using some old stuff lying around I've upgraded it to be a 2012 server, with 16GB of RAM, a 1TB HDD based primary array and a 1.8TB HDD based secondary array. This one is as solid as the other! I've since moved the bulk of the family data to it, configured some nice backups and off it goes. I've even put Hyper-V on it and run up a 2016 test server - it goes quite well.

All in all, I've spent under $1000 for these two servers and they comfortably handle everything I'm throwing at them. The original server, at one point, was running 2008R2 with SharePoint live for a client with 20 people using it, several Linux servers and a Windows 2012 based file server - all on hardware that is 5 years old. The SSDs really make the machine fly - a worthwhile upgrade indeed. In fact, as they get cheaper I can see myself upgrading the data array to SSD... it'll be pretty good!

The next gen in the T110 - the T110 II has a better Xeon processor in it, with double the RAM capability and they also came out with hardware based arrays. I'm keeping an eye out for one even as I write this.

If you're looking for a server to play with, or to manage a small workforce, then it's hard to go past something like this. Need redundancy? Buy two instead of one and set up live migrations (next on my to-do list).

I love this older tech - I can still get brand new replacement parts (like PSU's) and the original gear is running happily. It's cheap and it works - get around it!