Skip to main content

Extend virtual disk size of a VDI image



BACK UP EVERYTHING BEFORE TRYING THIS.
The entire process can be split into 4 stages.

1. Physically increasing the vdi file size on the host machine.


This requires help from the hypervisor OEM. For VDI, which is a native VirtualBox image, we'll use VBoxManage.

VBoxmanage modifyhd centos.vdi --resize 100000
If the above command doesn't work and throw an error about this feature not being implemented, you might try the following instead.

  • Create a new disk with higher capacity
  • VBoxManage clonemedium --existing

2. Resize the LVM.


For this we'll use GParted to resize the image. Boot up a GParted live CD and resize the required LVM partition to suit your need.

3. Resize the LVM-2

Boot up the machine with the newly extended image and check df -h and fdisk -l. You'll see that the disk has indeed grown, but LVM hasn't. Use the following command to resize LVM to full size.


  • pvresize /dev/sda2 (assuming your LVM partition is sda2. Replace as required.)
  • lvextend /dev/mapper/root -l+100%FREE (or, whatever your root logical volume is called.)

4. Extend the disk file system using appropriate tool.

For example, for XFS use the following commands,
  • xfs_info /dev/mapper/centos-root
  • xfs_growfs /dev/mapper/centos-root
This should make df as well as fdisk reflect the changes in disk space.

BACK UP EVERYTHING BEFORE TRYING THIS.
Labels:

Comments

Post a Comment

Popular posts from this blog

Multimaster replication with Symmetric DS

Symmetric DS is an awesome tool for trigger based replication whcih works for all major database vendors, including but not limited to PostgreSQL, MySQL, MSSQL, Oracle and many others. Symmetric-DS is a java application and can execute on any platform on whcih JRE is available including Windows and Linux. Trigger based replication, in constrast to disk based (eg. DRBD ) or transaction log file shipping based or statement based , works by registering triggers on DMLs and sending the data thus generated to remote machines. Another very popular trigger based DB replication tool is Slony . Symmetric-DS in addition to being database agnostic also supports multi-master replication (MMR). MMR usecase involves multiple database nodes, connected in a pool with DML updates coming from any of them. This is different from the normal master-slave replication, where slaves are not expected to generate any data events, and the sole authority of database is the master. MMR requirement causes d...
1 comment
Read more

PC Power supply and hacks

For posterity and myself, I'm leaving some tips and tricks of PC Power Supply Unit (PSU) whcih is an SMPS (Switched Mode Power Supply). There are a variety of uses of a +12V, +5V and +3V DC power supply like lighting up an LED strip or powering a raspberry pi. There are various colored cables in a typical ATX 12V SMPS. I'll list out the various color lines and what they mean, Sr. No Cable color Number of cables in a PSU Use 1 Green exactly one (1) Wake up signal from motherboard. Pressing PC power button makes this signal carry wake up signal to PSU to start. Green needs to be touched with the any ground to make the SMPS start. For self-starting PSUs, green needs to be connected with one black all the time. 2 Blue exactly one (1) -12V 3 Purple exactly one (1) +5V standby. When power supply is on standby mode (not on by signalling green), this line can give 1-2 A current. 4 Gray exactly one (1) Power good signal. When PSU levels has reached specificati...
3 comments
Read more

Cryptographic Primitive III: RSA Asymmetric Keys

RSA cryptosystems involves, a private key (which is kept private) and a public key, which is kept public i.e. known to everyone. The security of RSA hinges on the mathematically difficult problem of finding prime factorization of a very large number. Let's quickly disuss how a public, private key pair can be generated, Let, p and q be two large primes, then $n = q \times q$ $\phi(n) = (p-1) \times (q-1)$ Here, $\phi(n)$ is called euler's totient function Choose a random number $e$ such that, $e \in \left\{0,1,2...\phi(n)-1\right\}$ and $gcd(e,\phi(n)) = 1$ The gcd condition will ensure that we have an inverse of $e$ in $\mathbb{Z}_{26}$. Now, using extended euclidian algorithm one can get the inverse of e as d such that, $d \equiv e \pmod{\phi(n)}$ So, there we have it, the private key is $e$ and the public key is $(n,d)$. Few points to note here are, $p$ and $q$ are both $\geq 2^{512}$, although the recommened size is $2^{1024}$ $n$ is $\geq 2^{1024}$, although the recommended...
Post a Comment
Read more