Prepare Your Cloud Block Storage Volume

Previous section: Create and attach a Cloud Block Storage volume

After you have created and attached your Cloud Block Storage volume, you must prepare it for use on your server. To prepare the volume, you must partition, format, and mount it. After you have completed these steps, your volume is usable like a drive on your server.

Prepare your volume for use with a Linux Server

Use SSH to Connect to your Server

The server generation process creates a password that you need for this step.

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If you do not have the password, click the gear icon next to the server name and select Change Password.

  1. Log in to the Cloud Control Panel.

  2. In the top navigation bar, click Select a Product > Rackspace Cloud.

  3. Select Servers > Cloud Servers, click on the server and find the IP address for your server.

  4. Using SSH, log in to the server as root by using its IP address and root password.

    The output should be similar to the following example:

    $ ssh [email protected]
    [email protected]'s password:
    
    Linux nosnetdfw 2.6.32-31-server #61-Ubuntu SMP Fri Apr 8 19:44:42 UTC 2011 x86_64 GNU/Linux
    Ubuntu 10.04 LTS
    
    Welcome to the Ubuntu Server!
    * Documentation:  https://www.ubuntu.com/server/doc
    Last login: Thu Oct 18 02:26:38 2012 from 70.114.215.201
    
  5. After you log in, list the disks on your server. Your volume typically displays as the last drive in this list. In the following example, the 100 GB volume created in the Create and Attach a Cloud Block Storage Volume
    article is attached to /dev/xvdb.

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    It displays as 107.4 GB because of the way that the system counts megabytes.

root@nosnetdfw:~# fdisk -l

Disk /dev/xvda: 42.9 GB, 42949672960 bytes
255 heads, 63 sectors/track, 5221 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x000dc852

  Device Boot      Start         End      Blocks   Id  System
/dev/xvda1               1        5222    41942016   83  Linux

Disk /dev/xvdb: 107.4 GB, 107374182400 bytes
255 heads, 63 sectors/track, 13054 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x00000000

Disk /dev/xvdb doesn't contain a valid partition table

Partition the Disk

Partitioning the disk tells the server how much space on the drive you want to use. To use all of it, tell the server to start at the first cylinder of the disk and go to the last.

  1. Run the fdisk utility and specify the disk:

    root@nosnetdfw:~# fdisk /dev/xvdb
    
    Device contains neither a valid DOS partition table, nor Sun, SGI or OSF disklabel
    Building a new DOS disklabel with disk identifier 0x59a4ec2c.
    Changes will remain in memory only, until you decide to write them.
    After that, of course, the previous content won't be recoverable.
    
    Warning: invalid flag 0x0000 of partition table 4 will be corrected by w(rite)
    
    WARNING: DOS-compatible mode is deprecated. It's strongly recommended to
         switch off the mode (command 'c') and change display units to
         sectors (command 'u').
         
    
  2. Enter n to create a new partition.

  3. Enter p to indicate a primary partition.

  4. To create only one partition on this disk, enter 1.

    Partition number (1-4):
    First cylinder (1-13054, default 1):
    
  5. To accept the default start cylinder, which is 1, press Enter.

    Using default value 1
    Last cylinder, +cylinders or +size{K,M,G} (1-13054, default 13054):
    
  6. Press Enter to use the default, which is 1. Because you are using the entire volume for your partition, start the partition at the beginning.

    Using default value 13054
    
  7. Enter w to write the partition.

    w
    
    The partition table has been altered!
    
    Calling ioctl() to re-read partition table.
    Syncing disks.
    
  8. List the disks on your server again. Your Cloud Block Storage volume is ready as a disk. It was attached at /dev/xvdb and you created one partition on it, so now your available disk appears at /dev/xvdb1.

    root@nosnetdfw:~# fdisk -l
    
    Disk /dev/xvda: 42.9 GB, 42949672960 bytes
    255 heads, 63 sectors/track, 5221 cylinders
    Units = cylinders of 16065 * 512 = 8225280 bytes
    Sector size (logical/physical): 512 bytes / 512 bytes
    I/O size (minimum/optimal): 512 bytes / 512 bytes
    Disk identifier: 0x000dc852
    
        Device Boot      Start         End      Blocks   Id  System
    /dev/xvda1               1        5222    41942016   83  Linux
    
    Disk /dev/xvdb: 107.4 GB, 107374182400 bytes
    255 heads, 63 sectors/track, 13054 cylinders
    Units = cylinders of 16065 * 512 = 8225280 bytes
    Sector size (logical/physical): 512 bytes / 512 bytes
    I/O size (minimum/optimal): 512 bytes / 512 bytes
    Disk identifier: 0x59a4ec2c
    
        Device Boot      Start         End      Blocks   Id  System
    /dev/xvdb1               1       13054   104856223+  83  Linux
    

Format the Volume

Formatting the volume enables the server to store information on it. The following example uses ext3. However, you can use other file systems supported by your kernel, such as ext4, in place of ext3.

root@nosnetdfw:~# mkfs -t ext3 /dev/xvdb1

mke2fs 1.41.11 (14-Mar-2010)
Filesystem label=
OS type: Linux
Block size=4096 (log=2)
Fragment size=4096 (log=2)
Stride=0 blocks, Stripe width=0 blocks
6553600 inodes, 26214055 blocks
1310702 blocks (5.00%) reserved for the super user
First data block=0
Maximum filesystem blocks=4294967296
800 block groups
32768 blocks per group, 32768 fragments per group
8192 inodes per group
Superblock backups stored on blocks:
32768, 98304, 163840, 229376, 294912, 819200, 884736, 1605632, 2654208,
4096000, 7962624, 11239424, 20480000, 23887872

Writing inode tables: done
Creating journal (32768 blocks): done
Writing superblocks and filesystem accounting information: done

This filesystem will be automatically checked every 31 mounts or
180 days, whichever comes first.  Use tune2fs -c or -i to override. 

Mount the Volume

After partitioning and formatting the volume, you must mount it on the server. After the volume is mounted, it is available for use.

Run the mnt command and assign the volume a name for use on your server. In the following example, the volume is named cbsvolume1.

root@nosnetdfw:~# mkdir -p /mnt/cbsvolume1
root@nosnetdfw:~# mount /dev/xvdb1 /mnt/cbsvolume1/

After the volume is mounted, the system does not send feedback. However, you can check that your volume is ready by running the df command to show your free disk space. Your new volume is listed last in the list of available drives.

root@nosnetdfw:~# df -h

Filesystem            Size  Used Avail Use% Mounted on
/dev/xvda1             40G  632M   37G   2% /
none                  493M  136K  493M   1% /dev
none                  498M     0  498M   0% /dev/shm
none                  498M   36K  498M   1% /var/run
none                  498M     0  498M   0% /var/lock
none                  498M     0  498M   0% /lib/init/rw
none                   40G  632M   37G   2% /var/lib/ureadahead/debugfs
/dev/xvdb1             99G  188M   94G   1% /mnt/cbsvolume1

Your drive is ready for use with your Linux server. However, you should consider performing the following step to ensure that your volume remains persistent after a server reboot.

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If you ever decide to move the volume to a different server, begin by un-mounting the volume. Use the unmount command to unmount the volume, and then repeat this Mount the volume process for the new endpoint.

Make the Volume Permanent

This step is optional, but it keeps your volume attached to your server after restarts.

Add your volume to the static file system information in the fstab file.

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In your fstab options, add the _netdev option. This option prevents attempts to mount the volume until all networking is running.

root@nosnetdfw:~# nano /etc/fstab

#
# /etc/fstab
# Created by anaconda on Tue May 29 20:13:27 2012
#
# Accessible filesystems, by reference, are maintained under '/dev/disk'
# See man pages fstab(5), findfs(8), mount(8) and/or blkid(8) for more info
#
/dev/xvda1          /               ext3    defaults,noatime,barrier=0 1 1

For this example, add the following line beneath /dev/xvda1... to add the volume to the static file system:

/dev/xvdb1 /mnt/cbsvolume1 ext3 defaults,noatime,_netdev,nofail 0 2

Now the volume persists on the server after the server restarts.

Prepare Your Volume for Use with a Windows Server

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The procedure examples add a 100 GB volume to a Windows Server 2012 server. The steps are similar for all Windows cloud servers.

Remotely Connect to Your Server

Your server creation process generated a password, which you need for this step. If you do not have the password, go to the Cloud Servers page of the Cloud Control Panel, click the gear icon next to the server name, and select Change Password.

  1. On the Server Details page of the Cloud Control Panel, find the IP address for your server.

  2. With the server's IP address and password, use Remote Desktop to connect to the server as an administrator.

    When you first log in and view the computer window, you do not see the Cloud Block Storage Volume attached to the server. In the following example, only the server's C drive displays.

  3. Open the Server Manager window by right-clicking on the Computer icon and selecting Manage.

  4. In the left pane of the Server Manager window, click File and Storage Services.

  5. In the left pane, click Disks. In the following example, a 100 GB volume is attached to the server. It is listed as Offline, it has 100 GB of unallocated space, and its partition size is Unknown.

Partition and Format the Drive

For Windows servers, you partition and format the volume by using the New Volume Wizard. The mounting process, called "bringing it online" in Windows terminology, is required before running this wizard.

  1. To bring the volume online, in the Disks pane, right-click the offline drive and select Bring Online from the pop-up menu.

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    If you want to move the volume to a different server, begin by un-mounting the volume. Repeat this same step, but select Offline to unmount the volume, and then repeat this *Partition and format drive process for the new endpoint.

  2. In the Disks pane, right-click the drive and select New Volume from the pop-up menu. In Windows Server 2008®, you right-click the unallocated drive and select New Simple Volume.

  3. Click Next. In the Server and Disk page, the unformatted Cloud Block Storage volume displays.

  4. Select the disk and click Next. If the Offline or Uninitialized Disk message appears, click OK.

  5. In the next three wizard pages, specify the drive size, the drive letter, and the format and name for the volume. Confirm your settings on the Confirmation page. In this example, the disk's full 100 GB is used, it is assigned the drive letter D, it is formatted as NTFS, and it is named My New CBS Volume.

  6. To complete the process, click Create.

    When you open the computer window now, the new Cloud Block Storage volume displays similar to a regular hard drive.

    Your volume is now ready for use.

Next steps: Create and use Cloud Block Storage snapshots