Saturday, 29 September 2007

Integral and differential operations over multiple variables

Wow that's quite a post title, isn't it?
Well the content of what I'm going to show is none the less!

My dear Alberto Tibaldi has provided his wonderful collection of notes of a course of Mathematics!
In particular, this essay regards (as the title says) integral and differential operations over multiple variables with lots of demonstrations and examples.
As usal everything edited with LaTeX. Great job Tibia!

Thursday, 27 September 2007

Always sync your RAID, but don't forget BACKUP

Welcome Back!
Yes I finally returned active after a bit of happenings that occurred me!
As I returned from the holidays I wasn't at all greeted by my pc since Windows decided that 65536 colours were too much for me and believed I just needed 4.
Also my Nec 1760VM LCD monitor presented his letter of resignation since it's getting old (5 years) and now it needs some time after receiving a video signal to warm up.
My linux partition was the only one happy to see me! Thanks Beryl!!!

Anyway just some days ago an horrible accident happened, as i removed one hd cable while cleaning the inside of the case, and that drive was part of a RAID 5 device. I put off resyncing with the other discs but after one or two reboots also another drive was out of sync and the controller (an Adaptec 2810) couldn't activate the raid any more!
In a nutshell, a 750GB drive failure!

I recovered a couple of files from part of the drives with R-Studio and File Scavenger but there was nothing to do since they couldn't detect where a stripe ended and another started! In fact i was able to restore just very small files not bigger than the stripe size!
Luckily I have a disc backup of my short movies, I published online my thesis and my best pics are on deviantArt; so there weren't too many "impossible" files, except for 2 unpublished ads I liked and captured (and which I SHOULD have uploaded to youtube, argh) and some captured videos i don't know if I still have on tape...

The lesson is: even if you have a RAID array of infinite disk with multiple redundancy or with an anti-voodoo course, always do BACKUP. In fact I was caught off guard because i tought that my raid would never let me down, and so i skipped doing backups!

Trying to look on the bright side, now that all my documents are gone, I don't have any .doc or .xls files! So i don't need m$ Office anymore (very nice thing since it appears that Excel 2007 is not able of calculating 850*77.1) and so i can freely use OpenOffice and Latex for my documents :)

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