Centos Public Mirror – http://centos.maulvi.net 15 October 2009
Posted by Maulvi Bakar in : Linux, Society, System , add a commentTo the world..
I present the Centos Public Mirror hosted on http://centos.maulvi.net
Basically, I’ve been installing and re-installing centos over and over and over.. Also, at any one time, I have a bunch of centos boxes running both physically and virtually. This prompts me to run my own centos mirror. It’s twofold – it saves time and make it easier for me to simply grab any packages.
Then I had a revelation – after leeching from the community, it’s time to give back something… This mirror is one small way I could do to give back and with a big THANK YOU to the wonderful centos linux community.
Enjoy!
Creating a new Linux RAID1 device and extending an existing LVM Volume onto it. RHEL/Centos 5 13 June 2009
Posted by Maulvi Bakar in : Linux, System , add a commentI’m seriously into server consolidation and virtualization. I’m going to eliminate my other VMWare server and just concentrate on one.
First order of the day is to upgrade the RAM and Available HDD space. Upgrading the RAM is simple enough, just add/replace the modules.
Expanding the available space is another matter. This is actually an extension of my previous posting – New HDD, enlarging Red Hat/Centos ext3/lvm partition, but there’s another factor in the equation, RAID1 (Mirroring) devices.
The existing root partition resides in an LVM partition which in turn resides in a RAID1 (Mirroring) Multi-Disk (MD) partition which is based on a twin 400GB HDD configuration.
I’ve acquired a pair of 500GB HDDs. Now to extend the existing LVM ontothe newly acquired disks in a RAID1 configuration.
Step 1 is to create Software RAID partitions on the said disks -
# fdisk /dev/sdc
# fdisk /dev/sdd
Create a new ’sdc1′ and ’sdd1′ partitions using type FD, which is Linux RAID Autodetect.
Next, we need to create the Multi-Disk Volume -
# mdadm --create /dev/md2 --level=1 --raid-devices=2 /dev/sdc1 /dev/sdd1
Since I already have ‘md0′ for my ‘/boot’ and ‘md1′ is the existing volume with the existing LVM that was the intended target for expansion, thus naturally I’m using ‘md2′.
Basically, I am creating ‘md2′ device in RAID1 configuration using 2 devices namely ‘/dev/sdc1′ and ‘/dev/sdd1′.
You can monitor the status of your RAID devices using ‘/proc/mdstat’ -
# cat /proc/mdstat
Personalities : [raid1]
md2 : active raid1 sdd1[1] sdc1[0]
487331648 blocks [2/2] [UU]
[>....................] resync = 1.9% (9622656/487331648) finish=90.0min speed=88417K/sec
The steps here onwards are basically the same as previously mentioned here, the only difference is the ‘/dev/md2′ device is the target.
To start, we need to create a Physical Volume within the newly created ‘/dev/md2′ RAID device.
# pvcreate /dev/md2
After that we will extend the existing volume ‘VolGroup00? onto the newly created physical volume.
# vgextend VolGroup00 /dev/md2
Once done, the next step is to extend the Logical Volume within the volume group to use the free space newly made available when you extend the volume group previously.
# lvextend /dev/VolGroup00/LogVol00 /dev/md2
Here is the difference where I did not specify the space size to extend as the default will be to use all available spaces.
And finally, we’ll enlarge the ext3 partition to make use of the newly available free space in the logical volume.
# ext2online /dev/VolGroup00/LogVol00
I hope you guys read this below before proceeding..
# man ext2online
WARNING
Note that resizing a mounted filesystem is inherently dangerous and may corrupt filesystems, although no errors resulting in data loss have ever been reported to the author. In theory online resizing should work fine with arbitrarily large filesystems, but it has not yet been tested by the author on a filesystem larger than 11GB. Use with caution. Backups are always a good idea, because your disk may fail at any time, you delete files by accident, or your computer is struck by a meteor.
It is a good idea to ‘e2fsck -f /dev/VolGroup00/LogVol00′ before doing anything.
Enjoy!
New HDD, enlarging Red Hat/Centos ext3/lvm partition 16 December 2007
Posted by Maulvi Bakar in : Home, Linux, System , 2 commentsHmmm,
Suddenly, I’ve run out of space on one of my servers at home. Solution, add a new harddisk, extend existing partition onto the new harddisk.. Simple right? Right…
Firstly, fix the new harddisk onto the machine. Fdisk it like thus -
# fdisk /dev/sdb
Create a new ’sdb1′ partition using type 8, which is Linux LVM.
Next, we need to create a Physical Volume within the newly created sdb1 partition.
# pvcreate /dev/sdb1
After that we will extend the existing volume ‘VolGroup00′ onto the newly created physical volume.
# vgextend VolGroup00 /dev/sdb1
Once done, the next step is to extend the Logical Volume within the volume group to use the free space newly made available when you extend the volume group previously.
# lvextend -L 40G /dev/VolGroup00/LogVol00
And finally, we’ll enlarge the ext3 partition to make use of the newly available free space in the logical volume.
# ext2online /dev/VolGroup00/LogVol00
I hope you guys read this below before proceeding..
# man ext2online
WARNING
Note that resizing a mounted filesystem is inherently dangerous and may corrupt filesystems, although no errors resulting in data loss have ever been reported to the author. In theory online resizing should work fine with arbitrarily large filesystems, but it has not yet been tested by the author on a filesystem larger than 11GB. Use with caution. Backups are always a good idea, because your disk may fail at any time, you delete files by accident, or your computer is struck by a meteor.
It is a good idea to ‘e2fsck -f /dev/VolGroup00/LogVol00′ before doing anything.
Enjoy!
Gnome-RDP, Terminal Server Client, vncviewer – Fullscreen woes! 12 December 2007
Posted by Maulvi Bakar in : Linux, System , 2 commentsWell, I am using Ubuntu 7.10 Gutsy Gibbon. Feeling gutsy right? 
Anyway, it seems that whenever I connect to a remote machine via VNC protocol, doesn’t matter what my client of choice, if I am using ‘Fullscreen’, I’ll be ‘Full Screaming’. Seems that the CTRL-ALT-ENTER does not work for me to switch windows. I’ll be stuck to the remote machine screen.
Fortunately, there’s hope yet. Press ‘F8′ button and voila! There’s a host of options in the menu revealed.
Enjoy!
unknown nfs status return value: -1 11 December 2007
Posted by Maulvi Bakar in : Linux, System, Unix, Work , 1 comment so farI’m trying to mount an NFS export from an AIX machine to a Linux client.
Had encountered the above problem. Apparently the NFS exports on AIX requires the client’s hostname and IP address within the /etc/hosts file.
Enjoy!
Blog Migration 31 July 2006
Posted by Maulvi Bakar in : System , add a commentI’ve always liked WordPress. It seems very customizable, full-featured and lotsa plugins for me to play around with.
Actually, I installed WordPress on Maulvi.Net a few days ago, but delayed the Data Migration from http://deunan.wordpress.com till earlier today. Everything works perfectly! All I did was a simple export from the old one to the new one.
Hello world! 27 April 2006
Posted by Maulvi Bakar in : System , add a commentWelcome to Wordpress. This is your first post. Edit or delete it and start blogging!
Yeah, yeah.. I get it.. This is the umphteenth time I started a blog.. Dunno whether this one lasts.. or maybe not.. I’ll damn well’ll give it a try.. a shot.. whatever..