galway – Atlantic Linux Blog http://atlanticlinux.ie/blog Thoughts on running an Irish Linux business Fri, 22 Aug 2014 15:00:13 +0000 en-US hourly 1 https://wordpress.org/?v=4.5.1 Repartitioning modern Linux systems without reboot http://atlanticlinux.ie/blog/repartitioning-modern-linux-systems-without-reboot/ http://atlanticlinux.ie/blog/repartitioning-modern-linux-systems-without-reboot/#respond Fri, 17 Apr 2009 15:30:02 +0000 http://www.atlanticlinux.ie/blog/?p=92 This one is for my own future reference as much as anything. Ever since the move to udev in Linux 2.6, I’ve found it neccesary to do the very un-Linux like thing of rebooting before the appropriate device appeared under /dev. This was only an occasional hassle but still, you shouldn’t need to reboot Linux for such a thing.

Thanks to Robert for his Google magic in turning up partprobe, part of the GNU Parted package. As the Debian man page for partprobe says

partprobe is a program that informs the operating system kernel of
partition table changes, by requesting that the operating  system
re-read the partition table.

Excellent! Parted is normally installed on Debian and Ubuntu by default anyways, if not, simply, aptitude install parted and you’ll have access to the excellent partprobe.

We were trying to add some additional swap to a running system, the full series of commands needed as follows (I could have used parted to create the partition  but the cfdisk tool has a nice interface),

  1. sudo cfdisk /dev/sda (and create new partition of type FD, Linux RAID)
  2. sudo cfdisk /dev/sdb (and create new partition of type FD, Linux RAID)
  3. sudo partprobe
  4. sudo mdadm –create /dev/md3 -n 2 -x 0 -l 1 /dev/sda4 /dev/sdb4 (our swap devices are software RAID1 devices)
  5. sudo /etc/init.d/udev restart (this updates /dev/disk/by-uuid/ with the new RAID device)
  6. sudo mkswap /dev/md3
  7. sudo vi /etc/fstab (and add a new entry for /dev/md3 as a swap device)
  8. sudo swapon -a (to activate the swap device)
  9. sudo swapon -s (to verify it is working)
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Subversion sparse checkouts http://atlanticlinux.ie/blog/subversion-sparse-checkouts/ http://atlanticlinux.ie/blog/subversion-sparse-checkouts/#comments Tue, 07 Apr 2009 21:52:42 +0000 http://www.atlanticlinux.ie/blog/?p=79 I’ve been using Subversion for a few years now but as with lots of technology I work with, I’ve learned enough about it to do the job I need to do but I’ve never dug into it exhaustively. It turns out a nice feature called sparse checkouts was introduced into Subversion 1.5. With Subversion,  you can either create one repository for each project or use a single repository for multiple projects. I like using a single repository for multiple projects but there are advantages and disadvantages to both approaches and it’s yet another source of religious debate and flamage so I won’t suggest which would suit your needs best.

One of the disadvantages of using a single repository for multiple projects is that any time you want to check out part of your repository, you either had to do something like this,

svn checkout http://www.example.com/svn/myrepo

to check out the whole repository (and if it’s a big repository, and you’re on a slow connection, you get to watch the world wide wait in action) or something like this

svn checkout http://www.example.com/svn/myrepo/oneofmyprojects

to just check out a teensie part of your repository which should happen faster than the former approach. The disadvantage to the second approach is that you end up with only part of the repository checked out and if you want another part in the future, you’ll have to check that out separately like

svn checkout http://www.example.com/svn/myrepo/anotheroneofmyprojects

Pretty soon, you’ll have a directory full of separately checked out projects, each of which you have to individually svn update, svn commit and so on. Hey, it starts looking like you have one repository for each project. Ideally, what you want to be able to do is to check out your entire repository but only the bits your are interested in, while keeping the option open of checking out other parts in the future and managing them all as the one repository that they are. Sparse checkouts introduced this functionality.

With svn’s sparse directory support, you can do the following,

svn checkout --depth=immediates http://www.example.com/svn/myrepo

This checks out the myrepo repository, but only to a depth of 1, that is, all files and directories immediately under myrepo but not any further subdirectories and files. So a directory listing of your checked out repository might look like,

oneofmyprojects/
anotheroneofmyprojects/
README.txt

This gives you an overview of the myrepo hierarchy without pulling all the files. Furthermore, it is sticky – any subsequent svn update commands you run will honour the scope you set in the first checkout.

If you now want to flesh out parts of the tree, you can do the following

svn update --set-depth=infinity myrepo/oneofmyprojects

This updates the contents of myrepo/oneofmyprojects with all children (files and subdirectories) ensuring you have a full copy of that part of the repository. If you subsequent run an svn update in myrepo – the behaviour for oneofmyprojects continues to be sticky and will result in an update of all files and subdirectories (while not checking out the children of any of  the other myrepo top-level directories).

Unfortunately, you cannot checkout a directory with depth=infinity and then update it to a reduced a depth (the behaviour only works in the direction of increasing depth for now).

More detail is available at http://svnbook.red-bean.com/en/1.5/svn.advanced.sparsedirs.html

I took a quick look at TortoiseSVN (a very nice graphical Subversion client for Windows) and if you do an SVN checkout it has an option  for Checkout Depth which I’m guessing provides the same functionality (but I haven’t tested it).

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Linux and the Semantic Web http://atlanticlinux.ie/blog/linux-and-the-semantic-web/ http://atlanticlinux.ie/blog/linux-and-the-semantic-web/#respond Sat, 28 Mar 2009 09:48:32 +0000 http://www.atlanticlinux.ie/blog/?p=66 I’ve recently (well, back in January, but it took me a while to blog about it) started working with the DERI Data Intensive Infrastructure group (DI2). The Digital Enterprise Research Institute (DERI) is a Centre for Science, Engineering and Technology (CSET)  established in 2003 with funding from Science Foundation Ireland. Its mission is to Make the Semantic Web Real – in essence, DERI is working on both the theoretical under-pinnings of the Semantic Web as well as developing tools and technologies which will allow end-users to utilise the Semantic Web.

The group I’m working with,  DI2,  has a number of interesting projects including Sindice which aims to be a search engine for the Semantic Web and a forthcoming project called Webstar which aims to crawl and store most of the current web as structured data. Webstar will allow web researchers to perform large scale data experiments on this store of data, allowing researchers to focus on their goals rather than spending huge resources crawling the web and maintaining large data storage infrastructures.

Sindice and Webstar both run on commodity hardware running Linux. We’re using technologies such as Apache Hadoop and Apache HBase to store these huge datasets distributed across a large number of systems. We are initially working with a cluster of about 40 computers but expect to grow to a larger number over time.

My role in DI2 is primarily the care of this Linux infrastructure – some of the problems that we need to deal with include how to quickly install (and re-install) a cluster of 40 Linux systems, how to efficiently monitor and manage these 40 systems and how to optimise the systems for performance. We’ll use a lot of the same technologies that are used in Beowulf style clusters but we’re looking more at distributed storage rather than parallel processing so there are differences. I’ll talk a little about our approach to mass-installing the cluster in my next post.

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It’s not easy to “Be with AIB” http://atlanticlinux.ie/blog/its-not-easy-to-be-with-aib/ http://atlanticlinux.ie/blog/its-not-easy-to-be-with-aib/#comments Wed, 01 Oct 2008 18:00:12 +0000 http://www.atlanticlinux.ie/blog/?p=39 So, given the recent armageddon^H^H^H^H^H … err, turbulence in the financial marketplace, we considered it prudent to follow the old adage of not putting all of our eggs in the one basket. I figured it’s as easy to open a few bank accounts while we have all the documentation pulled together. For reference, if you are a limited company and you want to open a bank account you’ll need the following,

  • The certificate of incorporation for your company (some banks seem to require an original, some seem happy with a photocopy)
  • The memorandum and articles of association of the company (a certified copy seems ok)
  • For at least 2 directors, proof of id e.g. a drivers license and a copy of a recent utility bill for each of those 2 directors.

Finally, you’ll need to complete an application form when you go to the bank.

After some quick research on the internet to find the most local branches of our desired banks, we checked their opening times. This was our first surprise, most banks seem to only open at 10:00am. Or 10:30am for some banks on some days of the week. 10:30am? Since when did banks start working half days (they close again from 1:00pm to 2:00pm and again at 4:00pm, it’s like they don’t want our business).

First to our local Ulsterbank branch, one of the early risers, opening their doors at 10:00am. Clearly these guys want our money! Why Ulsterbank you might ask? No strong reason – their branch is nearby and I’d like us to put some of our eggs in non-Irish banks just to have a good mix (Ulsterbank is owned by Royal Bank of Scotland). The only downside to dealing with a non-Irish bank at the moment is that they only guarantee your deposits up to a maximum of €100,000 as per the Irish government’s recent announcement rather than yesterdays Irish government announcement which only covers Irish banks. In we go and ask to speak to someone about opening a deposit account for our limited company. We’re quickly introduced to a business banking person who takes us into his office, quickly explains our options and then proceeds to take the necessary documentation from us and copy it while we complete a nice minimal set of paperwork which asks us for sensible details about our company, the directors, what kind of account we require and so on. All told, I think it took as 15 minutes. The staff member thanked us at the end of the process and told us our account should be open by tomorrow morning.

Not bad, I thought to myself – clearly they value their customers and are interested in doing business with them.

Since we were on a roll, and we had all the documentation pulled together – we decided to also open an account with an Irish bank due to their recent success in obtaining the full backing of the Irish government (I’d have to start a whole new blog to discuss the wisdom of this, other than to wonder what troubled businesses will next be backed by the government … builders? Oh wait, they’ve committed to doing that already). The banks given unlimited coverage in yesterdays move by the Irish government include,

After a long strategic discussion (we checked which one had a branch closest to us) we opted to open our second account with Allied Irish Bank. They’re big, they’re guaranteed by the Irish government and they have lots of branches (and staff, I think I read somewhere before that AIB are by far the largest banking employer in Ireland).

So off we went to their local branch, wondering whether AIB would be even more efficient or whether they’d greet us with the smugness of a bank who’s just been given a large unsigned cheque by the Irish government. Opening their doors at 10:30am on Wednesday, AIB are one of the late risers of the Irish banking scene. We entered the branch, approached the customer service desk and explained that we wished to open a deposit account for a limited company.

“Do you want to do this today?” we were asked.

I wanted to open the account in the next 10 minutes if at all possible but I kept it to a simple “yes” to avoid any confusion.

After clarifying that we had all the required documentation, we were issued with a large lengthy application form to be completed in full (her emphasis, not mine).

I handed over our documentation to be copied – the same documentation that had sufficed not a half hour earlier at Ulsterbank.

“This certificate of incorporation is a copy, we need the original”.

“Why?” I asked.

“We just do”

As luck would have it, we had come prepared and had our pristine original. We handed it over to be reviewed and watch in horror as the AIB staff member proceeded to start stamping everything with a magic AIB stamp, including our original certificate of incorporation. This is a valuable legal document and there was AIB happily stamping it. I pulled my hands back from the counter, fearing where the stamping frenzy would stop and then demanded back our certificate of incorporation (my colleague wasn’t quite so polite and expressed his confusion as to why AIB had defaced our property).

“It has to be stamped” we were informed.

Anyone else that we have to present our certificate of incorporation to will be very impressed that AIB have stamped it – it harkens back to the days of bank managers being trusted … oh wait, they’re still elevated to such a position by the government.

After safely securing the return of our other documentation, our other identification was demanded. After getting the AIB staff member to promise not to stamp our drivers licenses (maybe the Gardai let your drive faster if you’re license has been stamped by AIB?) we handed them over to be copied and went to complete the form.

The first thing that struck me about the form was how much more detail we had to supply. The second thing that struck me is that the form had been designed to look pretty rather than be easy to complete.

I think we’d already spent more time with AIB at this stage than Ulsterbank had consumed, but we felt we must be there and must be within minutes .. or at least 24 hours of having an AIB account. We returned the completed application and received back our forms of identification.

“That should be up in about a week” we were told, in a tone of a voice that suggested we were lucky to be the recipients of such efficient service.

“What?” I asked, “we just opened an account with another bank and were told it would be up and running tomorrow morning”.

“Well, we have to run security checks on your identification and your company”.

“But a week …. ?” I asked?.

The staff member was having none of it. It takes a week to open an account with AIB and thats the end of the matter. Clearly if we didn’t like that state of affairs, we could take our business elsewhere. It’s not like AIB is stuck for cash – oh wait, all of the banks are stuck for cash at the minute, wouldn’t they be glad of your business? So, the Irish government can introduce a new piece of legislation for banks in about 24 hours while it takes one of those banks 7 days to create an account, into which we’ll be putting our cash.

I’ll let you know if we fail the security checks – but it’s clear to me now why at least one Irish bank needed to have the kind of guarantees that the Irish government has offered. They’re not getting business in the door because of how they treat their customers.

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Experienced Linux Engineers Wanted http://atlanticlinux.ie/blog/experienced-linux-engineers-wanted/ http://atlanticlinux.ie/blog/experienced-linux-engineers-wanted/#respond Fri, 13 Jun 2008 12:42:47 +0000 http://www.atlanticlinux.ie/blog/?p=29 We have experienced excellent growth in our business over the last few months. We have a number of exciting projects in the pipeline and are looking to expand our team. We’re currently seeking an experienced Linux support engineer to work as part of our team. It’s an interesting position and you’ll get to work with a wide range of technologies and customer environments. If you’re interested, take a look at the job specification. If you meet the requirements we’d love to hear from you.

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Atlantic Linux launches new website http://atlanticlinux.ie/blog/atlantic-linux-launches-new-website/ http://atlanticlinux.ie/blog/atlantic-linux-launches-new-website/#respond Mon, 26 Nov 2007 12:47:13 +0000 http://www.atlanticlinux.ie/blog/?p=32 Atlantic Linux, the Linux® business of Applepie Solutions has just launched it’s new website. Atlantic Linux will focus on delivering Linux consulting, design and support services to small, medium and large organisations. We look forward to your feedback and comments on our website.

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