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LVM to the rescue

Scenario. Have a system with a dying raid. 2 drives (R1), In  raid1, one drive has a device error, the other is listed as degraded. Rebuild halted at some 80%, won't continue due to the device error on drive 1. Can't rebuild from drive 2 because it contains a degraded raid image, and 3ware is picky about stuff like that.

 We can get the data off the raid, it's working for that for now. 

Now, the raid device is used in an LVM volume group, (vg00) and there's another raid (R2) on the box, using 8 drives, that has about 1TB of info on. All slots are full. What to do? 



 Remove one of the second raid drives, (thus putting R2 into a degraded state) put spare drive for R1 in that slot. Remove the *degraded* drive from the first array, and create a new array with the new drive, and the degraded drive.

Now, add that new raid (R3) to vg00 by creating a physical volume on that raid, and adding it to vg00. Next is the cool bit, using pvmove, we push the data off of R1 onto R3, then we remove R1 from the volume group, and can delete that raid, and remove the drive, then replace the drive we pulled out from R2 above

All data migrated, no data loss, no service interruption. I love lvm

Couple of caveats, R3 has to be able to hold all the data that was on R1, if something happens to R1 during this time, you are in trouble (but you would be anyway, since the raid is degraded) and you have deliberately degraded R2, which could bite you in the nether regions if murphy hates you.  You could do this with an external USB drive, or any other datastore, a SAN, etc, but we didn't have that option in this case. 


 Probably other ways we could have handled this, but this worked well.





Welcome to Singularity's Blog. Here we will talk about Linux and related matters. All in a new critical point of view. In this blog you will see more about ethics, philosophy, development, industry behavior, economics, political, coding, Linux and FOSS communities, taboos (and fake-taboos), and all know topics related.

 We will also  discuss more about applications and tendencies behaviors, and many problem-solution environments in the market, government and educational targets - in many countries.



why gentoo? why blog?

who I am:

           I am a Pre-Medicine student of the University of Kansas completely obsessed with Linux and Open Source movement in general. I am originally from Russian Federation where I grew up as a usual Windows user and, as everybody else, due to financial situation could hardly imagine a WinXP being sold for more than ~1$ and without activation key included. Cracks, CD-Keys, Serial numbers and the ways to work around different types of CD copy-protection is the kind of information our community of average teenage computer users was usually exchanging. I didnt know the alternative; I couldn't imagine any other way of life. It all changed a year ago when a friend of mine (whom I knew for long time as a person always way ahead of me in computer knowledge) in response to some whining about how slow XP works on my free Pentium III asked: "what? You still don't use linux??? O_o" That's where it all started for me...

why gentoo:

           The first distribution I tried was popular Ubuntu Hardy. I was freaking out about actual installation because I had no idea about how it is going to work on my old free computer, what programs I couldn't run on it, and, most importantly, the drivers, especially printer (because as a college student u have to print almost everyday and the installation of HP drivers even on Windows at that point seemed to me as a whole other impressive and glorious hour long process). I followed everybody's advice and loaded the OS from CD. Surprisingly, just from that freaken liveCD, without installation of any "drivers" (you know ... I was using windows for long time!!!) I was able to go on-line, download a pdf lecture for, as I remember right now, Ecology class (good to know :) and print it out on my HP printer! Next thing I remember I was erasing windows and installing Ubuntu on my HD.

            Not long after that, in again one of the conversations with THE friend we started talking about the different distributions. I remember him saying: "ah... all of those gnomed guied to hell windows-like distros! Look man, if you wanna try a real Linux, get something Gentoo" At that point I had (as I mentioned earlier) a very old PENIII with 256mbRAM Dell computer and the only thing that really mattered for me was speed! Guided by my friend (see above) and seduced by the word "performance" in the description on the gentoo's website I decided to give it a try. Long after many different experiences with this OS (which I am going to tell later in the blog) I can finally say it works, works like I want, and does it really fast.

why blog:

            Blogging about experiences with gentoo is interesting because of two reasons. First, it is sometimes helpful to have a little personal reference of all the issues you have with it and what kinds of solutions you could find. Furthermore, people might read it ("surprise-surprise"), see how stupid you are and point to the source of the problems or even tell you their ways of solution (this is how in reality this all "sharing information inside of the community blablabla" is usually represented :) . Second, it was many times mentioned to me how hilarious it is sometimes for gurus to read about computer problems of noobs. Gentoo is I think the BEST example of an operating system which a person without much experience with at least Unix shouldn't touch. At the moment when I decided to start using gentoo I had NO knowledge of bash, unix, computer programming, Linux as an operating system; kernel for me was a very pretty word, and terminal was that thing that always somehow knew my name, had @, ~, and a $ for some reason and whatever I typed in there gave me "command not found". Nevertheless, I thought I was ready ... :-)

Next Entry: First Installation

Now thats Customer Service!

Today I got back to work after a very busy morning and sitting there at my desk was a package. I picked it up to see what it might be and it was from Canonical. Ah ha! I remember about a month ago I signed up to have a free copy of Ubuntu 9.04 shipped to me after it was released. Didn't cost me a thing, just gave 'em my email address, address, and name and here it is.


How bout that for customer service? And not only that but this was a real silk-screened CD. Complete with a nice case and a few Ubuntu stickers. This would cost Hundreds of Dollars if it was a Microsoft product. I haven't been in much of an Ubuntu mood lately, what with the Mandriva release and all. But after this kinda treatment I think I'll give it a shot! Kudos to Ubuntu for going the extra mile.


Ubuntu 904


Mandriva is back!

As soon I saw that the Spring edition of Mandriva 2009 was finally out I downloaded the ONE edition ISO and burned it to a CD. I decided to use one of my spare hard drives to load it on because I have an openSUSE 11.1 install currently on my home machine and everything works beautifully on it and I didn't want to mess up a good thing. I booted up to the live CD and was greeted with that good old Mandriva intro sound effect meaning that it had correctly configured my sound device. I didn't waist any time with the live CD I immediately launched the live installer and preceded to install to the internal HD.

The installation went off without a hitch, but this was to be expected from Mandriva. They have always been one of my favorite distros. Mandriva was one of the original distros I tried when I first got into Linux. I have always found their products to be very refined and extremely professional. This release is no different and the only reason I switched to openSUSE since the last Mandriva release was because I was having weird problems with VMWARE server and it seemed to work flawlessly on openSUSE. I have to have a way to run virtual machines because I am constantly testing different setups and trying new things out and I seldom want to use an entire hard drive just for testing. We will get to that later.

First let me say that the first release of Mandriva 2009 was one of the first major distros to adopt KDE 4 and for all I know that could have been the reason for some of the weird problems I had. This time around the version of KDE is up to 4.2.2 and they have definitely ironed out some of the wrinkles and done a lot of refining because everything runs better and is much more fluent. This is the exact same hardware I had before too so it has to be an improvement in either the desktop environment or the kernel. After changing some of the packages that come by default and adding some of my own favorites I had everything operational within an hour.

The version I installed called "One" comes with Flash and Java and a lot of other things that you have to add yourself on other distros. I added DVD playback, Compiz Fusion, and for some reason there was no BitTorrent client so I added Ktorrent. From my experience its the best. I usually even add it when I do a Gnome install. I like it better than any of the Gnome clients. I then installed the free version of VMWARE server and it installed fine and so far has run great. If you have any trouble getting things to work I would suggest checking out THIS site. Lots of great help over there just click on your distro. Overall I am very impressed with this release if you would like to grab a copy for yourself just head over to MANDRIVA's website and download it for yourself.


Distros as I see them.

Over the years, ok not so many I have only been using Linux for about nine years now, I have managed to try the big hitters in the Linux world, the Slackwares, Red Hats, and Debians, and many variations and this is what I have found to be true.  Red Hat and Novell Distributions seem to be geared towards Enterprise systems with a lot of offerings for businesses, Debian distros are more geared for end-users, and Slackware seems to be for the tweakers.

 Ok so what do I like and why.  Source-based distributions (have to mention OpenSDE here) are fun to play with but hard for someone like who is based almost entirely in a GUI environment thanks to my Windows training.  Debian I love as a server distro and haven't found a need to use anything else.  Opensuse I love on my desktop.  If you run Gnome I find you hard to use, sorry remember Windows Guy, and I tend to swing towards distros that use KDE because of this.

 What I look for in a distro is simple.  KDE is a must and now that 4 is stable I like it over 3.  Wireless support because I use it on my laptop.  A strong repository,  I don't know about you but with me I have tried some of these obscure distros with weird package management, that they hope will be the next RPM, DEB, or TGZ (not sure if this is what Slackware is still using, could Google it I guess) but doesn't have support for your favorite tools, or applications, and you can't find the app that you need at that moment.  Standards, ok this goes to the repository bit too, how many differant versions of anything do we need.  Granted most of the distros nowadays are based in Debian or RPM (note: I didnt say Red Hat because Novell fits this category too) and so the standard for me tends to be one of these two package management system and Common Toolset.

 If I were to build my own distro.  So this is the part where I get creative and you can all yell at me later because I am being unrealistic.  <edited due to unreasonable thinking>  This section will be filled later.

 In conclusion, still much to learn.  However, my favourites are  Opensuse and Debian, and if someone wants to chime in and give me a few suggestions I don't mind, especially source based I wouldn't mind trying that again.


1st entry

hello world!

Congratulations on the new

Between the new and, not to mention MontaVista's announcement today of one of my favorite projects, I don't expect to get anything new done for the rest of the week. 

For what it's worth, I think the blog editor is excellent.  The hypertext link entry button works for me.

 MontaVista's announcement is for MontaVista Linux 6, an "integration platform" using a highly customized BitBake with MontaVista Linux to help developers create embedded Linux projects.  I'll be writing more about it on my personal blog as well as my blog at MontaVista.


New site, new user, and new laptop; what a combination

Wow. Just wow. The new site redesign is tasteful, functional, and all-around wonderful. It's about time that linux had a website that helps to alleviate that outdated concept that linux just isn't "pretty" or user-friendly.

That being said,  I got my HP Mini 1000 yesterday, and almost immediately dumped their MI software (based on the somewhat 'dated' Ubuntu 8.04, it seems) for Ubuntu Netbook Remix (since my last linux laptop broke a little while back), so this seems like a good time to emmerse myself in a growing linux community such as this.

 I hope that I can contribute and help this site to grow!


My Fully Functioning Arch Linux Laptop


Dell Inspiron 1525N (Alpine White)
15.4 inch Widescreen glossy display (1280x800) & 2MP Webcam
Intel Core 2 Duo T7250 (2.00 GHz, 800 MHz FSB, 2MB L2 Cache)
4GB DDR2, 667MHz 2 Dimm
Intel GMA X3100
160GB 5400RPM SATA Hard Drive
Integrated 10/100 NIC
Intel 3945 WLAN (802.11a/b/g) Mini Card
8X Slot Load DVD+/-RW Dual Layer Drive
8 in 1 card reader
Integrated High Definition Audio 2.0
Dell Wireless 355 Bluetooth Internal
85 WHr 9-cell Battery
Ports: 4USB, 1 IEEE 1394a, 2 Headphone, 1 Microphone, 1 Media Card, 1 S-Video, 1 VGA, 1 HDMI, 1 Ethernet, 1 Modem, 1 Power


/dev/sda1        /boot                       94.10MB

/dev/sda2        swap                         3.81GB

/dev/sda5        /                                 30.52GB

/dev/sda6        /mnt/virtual        30.52GB

/dev/sda7        /home                     84.10GB


Welcome !

Of course, this is my first post. I will dump all my Linux specific news items here and keep the rest (development and non-technical stuff) at my other blog.

I like the new and I have high hopes for it! Thanks to all the people involved behind the scenes!

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