Posted by Andreas on Sunday, March 23, 2008 at 23:42 (CET)
This weekend, the error message “device or resource busy” almost drove me crazy when I was trying to assemble (activate) a software RAID array.
I was experimenting with a software RAID-1 setup (two mirrored disks) using VirtualBox before planning to deploy it to a live server. Because I never liked the idea of creating 4 partitions on each disk and mirror them with individual arrays (/dev/md0 to /dev/md3), I planned to create one partitionable array that spans the whole disks (/dev/md_d0). I.e. the one and only array /dev/md_d0 consists of two whole disks /dev/sda and /dev/sdb. The advantage: the second drive is an exact copy of the first one – even partition table and master boot record are identically – just like with a hardware RAID. So in emergency cases, you can even use one of the disks directly, without activating RAID drivers.
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Posted by Andreas on Tuesday, March 04, 2008 at 09:16 (CET)
I encountered a really odd phenomenon with syslog-ng yesterday. A mail- and web-server with considerable traffic was disconnected from the net for some hours during a router failure. After the router came back online and the server was reachable again, I noticed an unusual high system CPU load. Strangely, the server itself wasn’t changed in any way (it wasn’t even shut down) and suddenly the CPU utilization raised to around 80%, whereas it normally stays under 20%. Strange thing was, that most CPU time seemed to be eaten up by the syslog-ng daemon.
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Posted by Andreas on Monday, March 03, 2008 at 10:26 (CET)
A few month ago, I wrote about my wireless mouse at home suddenly stopped working (losing sync to the receiver) and how to fix it.
Now it happens that I got an eVolution Orca (the successor of the Marlin) at the office. Guess what happened… A few days ago, the keyboard stopped working… The Orca doesn’t have any LEDs or switches and changing betteries didn’t help, so I called the support hotline again. Indeed there again is a method to reset and re-sync the keyboard: Take out the batteries and leave them out for 5 to 10 minutes. Indeed that worked for me.
I wonder what’s up with the Cherry eVolution devices that they occassionally lose their connection. With my Marlin wireless desktop at home, the mouse stops working every few weeks and has to be re-synced like described in my other posting. And now it’s the eVolution Orca at my office too. That doesn’t happen more often hopefully, since re-syncing means to take out the batteries for 10 minutes, which would be really annoying in the long run.