Feb 09

Web site backup and upload: rsync over sshfs (GoDaddy or other hosting with ssh access)

Other good people provided ideas for this solution:
notbrainsurgery @ livejournal
Robert @ softwarerevisions.blogspot.com

For some reason GoDaddy jailed hosting does not provide rsync, while it allows ssh user sessions to the host. It's not obvious how to move big chunks of data without "resume" functionality. Even worse for backup needs... Here's one of possible solutions based on my own experience. I hope this post could help someone too :) Continue reading

Feb 08

How did I discover and recover USB key disk geometry (on Linux)

It's relatively easy to screw the partition table on a USB key. I happened to have a quality 16GB USB key that got it all wrong (due to some of my experiments in the past :) - it was presenting itself as 250G drive. fdisk, sfdisk and hdparm all showed wrong disc geometry. I'd be happy to possess a little jewelry of 250GB, but I am afraid we'll have to wait a year or two for these to come. Sure I'd have problems should I try to use it as is for anything...Getting it all right turned out to be very simple - once I found what to do. Continue reading

Jul 22

VLC Babyphone: a webcam baby monitor – quick solution

Our baby started to crawl and he did it fast: he would fall from a bed or such before one can hear him. Hearing him crying afterwards was no joy at all, thus an audio-only baby-phone was definitely not a solution. I wanted to get something up very quickly, w/o purchasing extra h/w or spending much time. VLC came at resque. Nevertheless it took me some time to get it right - that's why here's yet another "webcam streaming server how-to".

Note: I did it all on Linux machines. But Windows adepts must not be discouraged: VLC runs there very well too, and it's a truly free software!

My video-surveillance streaming client-server set-up

First of all Continue reading

Jan 03

S/W RAID resync’ing all the time

Ever wondered why the heck mdadm & Co did not complain about failing drives, but the system was sluggish and blinked HDD activity LEDs as crazy? That's how it looked in my case:
[root@lemon ~]# cat /proc/mdstat
Personalities : [raid10] [raid6] [raid5] [raid4]
md5 : active raid5 sda3[0] sdb3[1] sdc3[2] sdd3[3]
     5809906944 blocks level 5, 64k chunk, algorithm 2 [4/4] [UUUU]
     [============>........]  resync = 63.2% (1224003712/1936635648) finish=2185.5min speed=5432K/sec
     bitmap: 1/231 pages [4KB], 4096KB chunk

I was observing this very often, thinking that one of my new drives went wonky already. Not to worry about: it was simply the kernel that did not display checking correctly, instead it wrote resync.

The following commands will reveal the real info about Continue reading

Dec 05

BIOS’es hang on 4K sector HDD

One would think that whatever we put on the hard drive - the BIOS should start and let us configure the system parameters. WRONG. With the new "Advanced Format" (the name (c)WDC) 4096 bytes sector technology it's no longer the truth. I tried two mobos (desktop dg33tl & a server one) with what one would name "properly aligned partitions" on WD20EARS - both ceased on booting, even entering the BIOS menu was impossible.

On one hand we want properly aligned partitions on our new tech drives: the write speed penalty for not doing so might be severe. It was 2 times slower in the quick tests I ran. IBM folks report up to 10 times worse writing performance in such case for certain conditions.
On the other hand the machine must boot, right?

A small investigation I conducted showed that the BIOS'es went wonky Continue reading