#centos 5

Vmware üzerine Centos 5 kurulumu nasıl yapılır?  Sorusuna cevap verecek olan bu makalemizde tüm detaylar hakkında bilgi sahibi olacaksınız. Basic Graphic Card haricinde nasıl kurulum gerçekleştiriyoruz bunu anlatacağız.

Öncelikle https://wiki.centos.org/Download adresinden kurmak istediğniz versiyonu seçip bilgisayarınıza indiriniz.

  İndirme tamamlandıktan sonra Wmware işletim sistemine giriş yapınız.

    Yukarıdadi resimde görüldüğü üzere Summary sekmesine tıklayınız, ardından sağtaraftaki Storage kısmındaki hddnize sağ tıklayarak Browse Datastore‘a giriş yapınız.

    Bilgisayarınıza indirdiğiniz Centos 5 ISO dosyasını upload ediniz. Ardından Centos 5 Sanal sunucu şablonunuzu oluşturup iso doyasını içersine yerleştiriniz ve sunucunuzu başlatınız. (Centos 5 Sanal sunucu şablonu oluşturmak içinde sitemizden arama yapabilirsiniz.)

  Üstteki ekrandan sonra aşağıdaki ekrana linux text yazıp devam ediyoruz linux text yazmamızdaki mantık text arayüzü ile sistemi kurmak zaten yazmaz ve otomatik geçmesini beklersek grafik arayüz gelecektir.

      Bu gelen ekranda dvd yi kontrol etmek istiyor skip ile geçip kuruluma devam ediyoruz.

Tuşlar arasında atlamayı tab tuşu ile yapıyoruz.

    Ok ile devam ediyoruz.

    Dil seçimi yapıyoruz benim önerim ingilizce dir siz kendinize göre seçim yapabilirsiniz.

    Klavye seçiminde ben genelde trq seçimi yapıyorum çünkü kullandığım pc ler türkçe klavyeye sahip ve türkçe karakterlerde sorun çıksın istemiyorum.

    Bu ekranda hdd ile alakalı bilgiler yer alıyor kabul edip devam ediyoruz.

    Burada harddiski nasıl kullanacağımız soruyor ben tamamen kullanmak istediğim için bütün veriyi silip tamamını sisteme vermesini seçtim sizde kendinize göre seçim yapabilirsiniz.

    Bu ekranda yine harddiskin tamamını sileceğini iletiyor yes diyoruz.

    Bölümlemede herhangi bir değişiklik yapıp yapmayacağımızı soruyor ben hayır diyerek devam ediyorum.

    Harddisk ayarlarından sonra ethernet ayarları geliyor yes deyip devam ediyoruz.

    Bu ekranda kullanmak istediğimiz ip sistemini seçip devam ediyoruz. Ben henüz ipv6 ya geçmediğim için v4 ile devam ediyorum

    Eğer dhcp niz aktifse otomatik ip ayarları ile devam edebilirsiniz ama ben manuel el ile ip verip devam ediyorum.

    Dns ve gateway bilgilerini girdikten sonra ok tuşu ile devam ediyoruz.

    Makina ismimizi giriyoruz bu ekrandan.

    Bu ekrandan ise sistemin zaman ayarını yapıyoruz turkiye icin aşağıdaki resimdeki gibi istanbulu kullanabilirsiniz.

    Sisteme bu ekranda root şifremizi tanımlıyoruz. Sunucu şifresi olacak.

    Sistemi nasıl kullanacağımızı bu ekrandan seçiyoruz ben sunucu olarak kullanacağım için server seçeneğini seçip devam ediyorum.

    Ok dedikten sonra paketler kontrol edilir ve sistemin son önizlemesi yapılır.

    Ok dedikten sonra harddisk formatlanır.

    ve artık kurulum başlar bilgisayarınızın konfigürasyonuna göre en fazla 15 dk sürer kurulum.

Writing this down in the hopes that it helps someone else.

I had a linux system running CentOS 5 on physical hardware with RAID 5. Two of the drives went down (one was bad and needed to be replaced while the other was just offline).

Despite the hardware array reporting good health, I got the following error upon boot:

Loading dm-message.ko module Loading dm-raid45.ko module device-mapper: dm-raid45: initialized v0.25941 Waiting for driver initialization. Scanning and configuring dmraid supported devices Creating root device. Mounting root filesystem. kjournald starting. Commit interval 5 seconds. EXT3-fs: mounted filesystem with ordered data mod. Setting up other filesystems. Setting up new root fs setuproot: moving /dev failed: No such file or directory no fstab.sys, mounting internal defaults setuproot: error mounting /proc: No such file or directory setuproot: error mounting /sys: No such file or directory Switching to new root and running init. unmounting old /dev unmounting old /proc unmounting old /sys ERROR opening /dev/console: No such file or directory Trying to use fd 0 instead WARNING: can't access (null) exec of init ((null)) failed!!!: Bad address Kernel panic - not syncing: Attempting to kill init!

After some research (and help from my serverfault brothers) I found the cause: The initial ramdisk was failing to root pivot because there were errors on the the root device. Specifically, the array had propagated filesystem inconsistencies after resync.

Options at this point:

Run fsck (or some other filesystem health utilty) on the root device(s) to find/repair issues... hopefully.

OR

Reinstall/reimage the OS.

In this case, it was faster/easier to just reimage. In any event though, it's a good reminder that RAID is never a backup... and that a damaged array will have a damaged filesystem on it.

Awhile back, I was helping a fellow admin troubleshoot a crash that occurred on a CentOS 5.x VM. I'll spare you the goring details of the events leading up to it but suffice it to say, there was a filesystem issue and upon rebooting, we saw this:

Checking filesystems / contains a file system with errors, check forced. /: Inodes that were part of a corrupted orphan linked list found. /: UNEXPECTED INCONSISTENCY; RUN fsck MANUALLY. (i.e., without -a or -p options) [FAILED] *** An error occurred during the file system check. *** Dropping you to a shell; the system will reboot *** when you leave the shell. Give root password for maintenance (or type Control-D to continue):

The catch? Neither of us knew the root password so we tried CTRL-D (which rebooted the system).

Initially, I thought that I could reset the root password by booting into single user mode or emergency mode (adding the single kernel option via the grub boot menu). Nope - no luck - even when booting in single user mode, the system still wanted to run the fsck operation and we came across the same auth prompt.

Eventually the other admin remembered the appropriate password and could continue on to the maintenance prompt to run fsck.

This got me to thinking though - what if we didn't remember the password? How could we bypass the login prompt and/or reset the root password under this specific circumstance? Is there a way to bypass the fsck check (and pretty much everything else) during boot?

Yup. Here's how:

1) Reboot the system. 2) Press any key at the grub boot loader prompt. 3) Select a kernel from the list (doesn't really matter which one) and press e. 4) Locate the kernel line and press e to edit it. 5) At the very end of the line, add init=/bin/sh (being sure to have a space before it). Press Enter. 6) Press b to boot with the special kernel options.

OK. So what exactly did we do here? By adding the special init line in step 5, we told the kernel to boot with a VERY early shell with almost no features (running /bin/sh in place of init).

The upside here is that this helps to bypass problem areas during startup (which is what we wanted). Of course, this also means that we might be missing critical stuff (like opening encrypted volumes, starting LVM, etc). Thankfully, my particular use case wasn't that complicated.

At this point, the shell appears but the root filesystem is mounted as read only (which prevents us from resetting the root password). If you were to try changing the root password, you'd see something like:

sh-3.2# passwd Changing password for user root. New UNIX password: Retype new UNIX password: passwd: Authentication token lock busy sh-3.2#

Sooooooooooo... let's continue with the process:

7) Remount the root filesystem by typing: mount -o remount,rw / 8) Reset the root password by typing passwd and following the prompts. 9) Reboot (reboot).

If you haven't installed it yet, just follow the fast steps below. Otherwise, go down to "Problems after install" to see some common issues you might run into.

Fast Steps

First, the fast summary if you're starting from scratch:

Follow all the instructions here: http://wiki.postgresql.org/wiki/YUM_Installation Then run these commands:

$ sudo yum install postgresql93-server postgresql93-dev postgresql93-lib $ export PATH=/usr/pgsql-9.3/bin/:$PATH $ pip install psycopg2

Problems after install

While running pip install psycopg2 you might run into this:

Error: pg_config executable not found.

This means that the right directory isn't in the system path. You can fix this by adding the path to pg_config to PATH.

First do this:

$ sudo locate pg_config

(If nothing shows up run sudo updatedb, then try locate again)

You might see something like:

/usr/pgsql-xx/bin/pg_config /usr/pgsql-xx/share/man/man1/pg_config.1

Where xx is the version number. Take everything before pg_config in the first line and add it to PATH thusly:

$ export PATH=/usr/pgsql-xx/bin/:$PATH

Now try pip again:

$ pip install psycopg2

If you see errors like:

./psycopg/psycopg.h:31:22: error: libpq-fe.h: No such file or directory ./psycopg/lobject.h:29:28: error: libpq/libpq-fs.h: No such file or directory

That means you probably don't have the PostgreSQL development package installed. Just run

$ sudo yum install postgresql93-dev

Then try

$ pip install psycopg2

Description :

liba52 is a free library for decoding ATSC A/52 streams. The A/52 standard is used in a variety of applications, including digital television and DVD. It is also known as AC-3. The package also includes a52dec, a small test program for liba52.

Information Tags :

Name        : a52dec Version     : 0.7.4 Release     : 13.el5 Architecture: x86_64 Size        : 99207 Packager    : http://free.rpmfusion.org/ Group       : System Environment/Libraries URL         : http://liba52.sourceforge.net/ Repository  : rpmfusion-free-updates-el5-x86_64 Summary     : A free ATSC A/52 stream decoder Source      : a52dec-0.7.4-13.el5.src.rpm

Description :

liba52 is a free library for decoding ATSC A/52 streams. The A/52 standard is used in a variety of applications, including digital television and DVD. It is also known as AC-3. The package also includes a52dec, a small test program for liba52.

Information Tags :

Name        : a52dec Version     : 0.7.4 Release     : 13.el5 Architecture: i386 Size        : 91779 Packager    : http://free.rpmfusion.org/ Group       : System Environment/Libraries URL         : http://liba52.sourceforge.net/ Repository  : rpmfusion-free-updates-el5-x86_64 Summary     : A free ATSC A/52 stream decoder Source      : a52dec-0.7.4-13.el5.src.rpm

Description :

DVD Rip-O-Matic is a simple DVD-to-XviD ripping application developed by Dik Takken. The wizard was designed to be very easy to use; it automatically detects the optimal settings for you. It should also produce very high quality AVI files, even if you have no idea what the settings mean and just use it in the next-next-next-finish way.

Information Tags :

Name        : DVDRipOMatic Version     : 0.95 Release     : 5.el5 Architecture: noarch Size        : 291957 Packager    :  Group       : Applications/Multimedia URL         : http://dvdripomatic.sourceforge.net Repository  : rpmfusion-free-updates-el5-x86_64 Summary     : Simple DVD to XviD ripping application Source      : DVDRipOMatic-0.95-5.el5.src.rpm

Description :

xhtml2ps is freely-available GUI frontend for html2ps, a HTML-to-PostScript converter.

Information Tags :

Name        : xhtml2ps Version     : 1.0 Release     : 0.b5.2.el5.rf Architecture: noarch Size        : 103943 Packager    : Dag Wieers  Group       : Applications/File URL         : http://user.it.uu.se/~jan/html2ps.html Repository  : rpmforge-el5-x86_64 Summary     : GUI frontend for html2ps, a HTML-to-PostScript converter Source      : html2ps-1.0-0.b5.2.el5.rf.src.rpm