276 reputation
19
bio website valedon.co.uk
location Derbyshire, United Kingdom
age 59
visits member for 2 years, 6 months
seen Dec 4 '14 at 13:02

I've worked in IT for about 30 years (since 1980) starting when I was doing research at university and got the role of Computer Manager in the Physics department. I've been at IT Manager for much of my career, but in recent years have done more software development (SQLserver, C#, VB.Net, MVC, ASP, etc) than IT administration. I've also been a Project Manager (Prince 2) and a software development manager.

Most of my professional work has been with Microsoft operating systems (currently Windows 8 at home) but I've kept up an interest in Linux throughout.

At work, I currently develop web applications using C#, jQuery/javascript and MS SQL.

At home, in addition to several Windows laptops, I currently maintain 2 systems running Linux. Both is running Debian + MythTV; one is used a Personal Video Recorder and general filestore (it has about 9.5Tb of disks attached). The other just acts as a player and alternates between Debian, for MythTV, and Windows 7, for iPlayer, BlinkBox, etc; it connects only by a WiFi connection which is configure to start before login so it also holds the essential config backup from the main server. Both use HD TVs as monitors. In the past, I've configured my home systems to use soft RAID (md devices) and currently have the PVR system using LVM as it allows partitions to span drives (and is easily reconfigurable when I need a bit more space).

I'd like to do a bit more with Android as I have a couple of tablets - my phones are a Blackberry and an iPhone! - and also get back to my Astronomy hobby (I haven't had my telescope out for a couple of years!

Married, with several cats, but no kids!


Mar
25
comment How do I start a second shell when in single user mode?
Just thought I'd report that I just spent over a week with a system in single user mode repairing a RAID array and openvt proved to be very useful. Thanks for bringing a new command to my notice.
Mar
21
comment How do I start a second shell when in single user mode?
This actually seems much easier that getty. I never realised it was already installed.
Mar
18
comment How do I start a second shell when in single user mode?
Tried it. It works, but since the login session isn't spawned from init, it doesn't get re-spawned if it dies.
Mar
18
comment How do I start a second shell when in single user mode?
The 'overkill' reference was more with regard to the windowing/split-screen capabilities of programs like tmux. After experimenting, I suspect that screen is probably more stable that getty in the single user environment.
Mar
16
comment How do I start a second shell when in single user mode?
This looks like what I'm looking for. I'll give it a try next time.
Mar
16
comment How do I start a second shell when in single user mode?
As Cristian says, I'd already considered screen and felt other multiplexers were even more overkill. All I need is a simple second console.
Mar
16
comment How do I start a second shell when in single user mode?
The point is that I don't want to suspend or interfere with the process running on the initial console. For example, when running ddrescue I don't want to keep interrupting and resuming it even though it's set up to do this..
Sep
5
comment How to find the reason for a weekly downtime on an Ubuntu web server hosted by AWS?
Obviously, my thought is that if the server doesn't seem to be indicating a failure it's likely to be external, i.e. maintenance on the hosting systems or external routers. Does it only affect the web server (port 80) or are other services unavailable, e.g. SSH (22), etc. Does the server continue to respond to ICMP pings?
Sep
4
comment How to find the reason for a weekly downtime on an Ubuntu web server hosted by AWS?
Did you ask AWS support if they could explain it?
Aug
24
comment Virtualbox, private network and access from host machine
+1 I think each VM needs 2 adapters too.
Aug
9
comment Linux: How to align partition and file system on hardware RAID
@longneck Agreed about not blindly setting values. Agreed also about benchmarking when adjusting anything. The problem I've found in the past comes when business users want to change applications but won't allow time/resource to test/adjust things for the way the new app works.
Aug
9
comment Linux: How to align partition and file system on hardware RAID
@javano This is what I meant by just letting the OS (specifically the partitioner application) do what it thinks is right. These days unless you are going to squeeze every byte out of disk, using the defaults usually gets most of what you want.
Aug
9
comment Linux: How to align partition and file system on hardware RAID
Regarding the parity distribution across disks, you are correct about RAID5, which is why I put in the "(simplistically)". As far as the math goes, you still lose a whole disk to parity whether it's RAID3 or RAID5. To be honest, I've never considered where a particular block gets written on a RAID array because, of course, for RAID to work, some part of each block actually gets written to every disk.
Aug
9
comment Linux: How to align partition and file system on hardware RAID
OK, following comment from @longneck I went of and read support.microsoft.com/kb/929491 and download.paragon-software.com/doc/… . The discussion refer to Windows only, but, if you want to be on the safe side, you should align you partition according to the stripe size, irrespective of the number of disks or the chunk size. I also came across this (zdnet.com/blog/storage/…) article, which recommends that for better I/O throughput, you should use a small chunk size.
Aug
9
comment Linux raid controller (LVM/MDADM)
What's the contents of /etc/mdadm/mdadm.conf? Presumably it identifies the arrays by UUID; can you just reboot the machine? With 2 dead arrays it's probably not doing anything useful. Alternatively, have you tried removing one of the 'failed' drives (mdadm /dev/md1 --remove /dev/sdi1 for example) and then adding its new version (if you can identify which one it is). If that works, then you can repeat until they are all back.