Pre-format checklist!

  Formatting your system to reinstall or upgrade your OS, or to try a new one? Here’s a few things worth checking before you do…  
  1. Export browser bookmarks
  2. Deactivate programs (e.g. Adobe CS*)
  3. Download updated drivers
  4. Check your Downloads folder for anything you might want to save
  5. Check your Documents folder for the same
  6. Check your Pictures/Music/Movies folders
  7. Lightroom user? Make sure you have copies of your catalogues
  8. Make note of your Windows/Office/other product keys (a program like Produkey can make this very easy for Windows/Office)
  9. Unix users – copy your crontab and other setup files (e.g. ssmtp, networking config) if they have changed
  10. Check for BIOS updates for your system
  11. Make note of your email client settings – can save you a lot of headaches trying to access emails post-reinstall
  12. Mine coins? Don’t forget to copy your wallet elsewhere. If you don’t have a backup, make one!
  13. Check your programs for data files which you may want to keep – e.g. Netmeter’s .txt file for logging traffic
  14. If you’re virtualising, check that you have copies of your VM HDDs! (e.g. Virtualbox)
  15. Check which programs you have installed (e.g. in Windows through Add/Remove Programs) – make a list if you might forget some
  16. Upgrading or changing OS? Check that anything important is compatible with the new OS before you start!
    We will be updating this over the course of the next week or so as we get ideas and feedback about what people typically forget about! Our own list of reinstalled programs looks something like:  
  • CS6 suite
  • LR5
  • Nik Collection
  • Notepad++/Sublime
  • Firefox/Chrome
  • Thunderbird
  • Open Office
  • XenCenter
  • Virtualbox
  • iTunes
  • MakeMKV
  • Handbrake
  • Audials
  • Antivirus
  • Microsoft Camera Codec Pack
  • Datacolor Spyder colour management
  • Net Meter
  • SD Formatter
  • SumatraPDF
  • ISODisk
  • HD Tune Pro

Ubuntu: Securing your remote SSH logins with Denyhosts

Being able to log in to your server remotely via SSH is an incredibly powerful way of remotely managing your system. With so many devices now able to support consoles (just about any current smartphone or current OS, really) you can check on things, update or make changes from just about anywhere.   One of the less positive consequences of opening up your SSH port to the wider world is that you’re also exposing your server to everyone else in the world, not just yourself. There are many computers and virus-born botnets out there who scan IP addresses for open ports and try to brute-force their way in to steal data, generally cause destruction or create another bot. One good way of protecting yourself is installing a program which monitors the attempted logins via SSH and blocks any IP addresses which match an undesired pattern: Denyhosts.   You can install denyhosts by entering the following:  
sudo apt-get install denyhosts  
This installs denyhosts on your system, which starts automatically once installed and also on boot. You can edit the settings with the following file:  
/etc/denyhosts.conf  
Blocked IPs are listed in:  
/etc/hosts.deny  
It’s not unusual to have hundreds of entries after a couple of months. The default settings are reasonably good; you do have the freedom to make them as lenient or paranoid as you care to which is handy for tailoring it to your specific needs (e.g. strict rules re: logging in as accounts that don’t exist or the root account). Be aware that if you mistype your own password enough times you may ban your ou cown IP address, which might be inconvenient if you don’t have physical access to the server or another IP to fix!   Denyhosts is a quick, easy and powerful way to begin securing your SSH-accessible servers – as far as we’re concerned it or an equivalent program are a must if you’re opening up a SSH port to the outside world.

Get yourself a UPS…

We had a lightning storm rcently; this was the view from our perspective:     We also got a call about a customer’s computer that was no longer working, along with most of the connected peripherals. This wasn’t a coincidence…   An uninterruptible power supply is a device which stores electricity in batteries and, when the power goes out, kicks the electricity supply across from mains to the batteries without missing a beat. Some better UPS models will also condition the power that comes through, compensating for brownouts or oversupply. Depending on the capacity of the UPS and the load of the devices attached to it you may end up with anything from minutes to hours of power supply; a small UPS will give you enough time to turn the devices off normally and some come with software to automate this process.   A larger UPS may be able to give you enough run-time to outlast the power blackout – this could be very valuable if you run very long processes that can’t be interrupted without data loss. Uninterruptible power supplies generally also provide surge protection., and the higher-end models isolate the power supplied to your systems from the mains power as much as possible – meaning that you have a much better chance of reducing or avoiding entirely the damage caused by power surges.   A basic UPS costs around $100, and for the protection they provide they’re a worthy investment. Protect your expensive electronic hardware today – drop us a line and we can set you up with a model that suits your needs.

Reminder: Check your backups!

Just a quick reminder today – remember to check that your backups still work, particularly those that are full and likely haven’t been added to for some time. It wouldn’t be a lot of fun having your main drive die and only then finding out that your backup drive kicked the bucket 6 months previous and nobody noticed.

Can you mix processor models in Intel’s Socket 2011 dual-CPU motherboards?

  Intel recommend using two identical CPUs in their socket-2011 dual-socket motherboards; it is theoretically possible to use non-identical CPUs, though, and Intel’s rules for that are that they must be:  
  • Of the same processor family
  • Have the same number of cores
  • Have the same cache size at each level of cache
  • Able to find a common QPI link frequency
  Given the above, Intel states that you can mix CPUs with different core frequencies – the faster CPU will clock down to match the slower one, however. The same applies to the QPI links.   We haven’t yet had the opportunity to test differing CPUs in other brands’ dual-socket motherboards yet – we will update if or when we do. This isn’t something which we would usually recommend without finding someone who has successfully tested your intended combination just in case, but it is handy to know that it is theoretically supported.

Array Best Practices & backing up

Something to think about – we had a couple of models from the same batch die within a day of each other recently, and while that may be coincidence there may also have been something about that batch that made them die under certain usage conditions or at a certain age. Now, if they had been a mirrored pair the mirror would have been lost and we’d have had to go to a backup to restore the data. Fortunately we had spread that batch out across several arrays so the failures didn’t result in any downtime and the drives have been RMA’d as per usual.   If you’re buying several drives at once this is something to keep in mind – try to source them from different batches if possible or spread the drives out so that if they do all fail in a short space you won’t lose anything. We certainly don’t keep our backups on the same media as our main arrays just in case something catastrophic happens to a batch of disks.   A good rule of thumb for valuable data is 3, 2, 1: 3 copies, 2 types of media, 1 offsite. If your data is important – family photos, important documents, anything that would be hard to replace or irreplaceable – remember to back it up. Even a drive or thumbdrive at a family member or friend’s house could save you if your home or work gets burgled.