Managing CPS Disks

Adding a New Disk

This section describes the procedures needed to add a new disk to a VM.

Prerequisites

  • All the VMs were created using the deployment process.

  • This procedure assumes the datastore that will be used to have the virtual disk has sufficient space to add the virtual disk.

  • This procedure assumes the datastore has been mounted to the VMware ESX server, regardless of the backend NAS device (SAN or iSCSI, etc).

ESX Server Configuration

Procedure

Step 1

Login to the ESX server shell, and make sure the datastore has enough space:

vmkfstools -c 4g /vmfs/volumes/datastore_name/VMNAME/xxxx.vmdk -d thin

Step 2

Execute vim-cmd vmsvc/getallvms to get the vmid of the VM where the disk needs to be added. 


Vmid Name                          File                    Guest OS    Version Annotation
173  vminstaller [datastore5] vminstaller/vminstaller.vmx centos64Guest vmx-08
Step 3

Assign the disk to the VM.

The xxxx is the disk name, and 0 and 1 indicate the SCSI device number.

In this example, this is the second disk:

vim-cmd vmsvc/device.diskaddexisting vmid /vmfs/volumes/path to xxxx.vmdk 0 1

Target VM Configuration

Procedure

Step 1

Log in as root user on your Linux virtual machine.

Step 2

Open a terminal session.

Step 3

Execute the df command to examine the current disks that are mounted and accessible.

Step 4

Create an ext4 file system on the new disk:

mkfs -t ext4 /dev/sdb

Note 
b in /dev/sdb is the second SCSI disk. It warns that you are performing this operation on an entire device, not a partition. That is correct, since you created a single virtual disk of the intended size. This is assuming you have specified the correct device. Make sure you have selected the right device; there is no undo.
Step 5

Execute the following command to verify the existence of the disk you created:

# fdisk -l

Step 6

Execute the following command to create a mount point for the new disk:

# mkdir /<NewDirectoryName>

Step 7

Execute the following command to display the current /etc/fstab:

# cat /etc/fstab

Step 8

Execute the following command to add the disk to /etc/fstab so that it is available across reboots:

/dev/sdb /<NewDirectoryName> ext4 defaults 1 3

Step 9

Reboot the VM.

shutdown -r now

Step 10

Execute the df command to check the file system is mounted and the new directory is available.

Update the collectd process to use the new file system to store KPIs

After the disk is added successfully, collectd can use the new disk to store the KPIs.

Procedure
Step 1

SSH into pcrfclient01/pcrfclient02.

Step 2

Execute the following command to open the logback.xml file for editing:

vi /etc/collectd.d/logback.xml

Step 3

Update the file element <file> with the new directory that was added in the /etc/fstab.

Step 4

Execute the following command to restart collectd:

monit restart collectd

Note 

The content of logback.xml will be overwritten to the default path after a new upgrade. Make sure to update it after an upgrade.

Mounting the Replication Set from Disk to tmpfs After Deployment

You can mount all of the members of the Replication set to tmpfs, or you can mount specific members to tmpfs. These scenarios are described in the following sections.

Scenario 1 – Mounting All Members of the Replication Set to tmpsf

Procedure

Step 1

Modify mongoConfig.cfg file using the vi editor on cluster manager. Change the DBPATH directory for the SPR Replication set that needs to be put on tmpfs.

Note 

Make sure you change the path to /var/data/sessions.1, which is the tmpfs filesystem. Also, make sure to run diagnostics.sh before and after the activity.

The following example shows the contents of mongoConfig.cfg file before modification: 
[SPR-SET1]
SETNAME=set06
OPLOG_SIZE=5120
ARBITER1=pcrfclient01a:27720
ARBITER_DATA_PATH=/var/data/sessions.6
MEMBER1=sessionmgr04a:27720
MEMBER2=sessionmgr03a:27720
MEMBER3=sessionmgr04b:27720
MEMBER4=sessionmgr03b:27720
DATA_PATH=/var/data/sessions.4
[SPR-SET1-END]

The following example shows the contents of mongoConfig.cfg file after modification: 

[SPR-SET1]
SETNAME=set06
OPLOG_SIZE=5120
ARBITER1=pcrfclient01a:27720
ARBITER_DATA_PATH=/var/data/sessions.6
MEMBER1=sessionmgr04a:27720
MEMBER2=sessionmgr03a:27720
MEMBER3=sessionmgr04b:27720
MEMBER4=sessionmgr03b:27720
DATA_PATH=/var/data/sessions.1/set06
[SPR-SET1-END]
Step 2

Run build_etc.sh to update the modified files.

Step 3

Verify that the sessionmgr-27720 files on sessionmgr VMs are updated with new DB_PATH by using vi or cat command.

Step 4

Stop and start the mongo databases one by one using the following commands:

systemctl stop sessionmgr-<port>

systemctl start sessionmgr-<port>
Step 5

Run diagnostics.sh.

Step 6

If this is an Active/Active GEOHA setup, scp the mongoConfig.cfg file to Site-B Cluster Manager, and run build_etc.sh to update puppet files.

Scenario 2 – Mounting Specific Members of the Replication Set to tmpfs

Procedure

Step 1

Ssh to the respective session manager.

Step 2

Edit the mongoDB startup file using the vi editor. In this example we are modifying the SPR member.

[root@sessionmgr01 init.d]# vi /etc/init.d/sessionmgr-27720

Step 3

Change the DBPATH directory from DBPATH=/var/data/sessions.4 to DBPATH=/var/data/sessions.1/set06.

Step 4

Save and exit the file (using !wq).

Step 5

Enter the following commands to stop and start the SPR DB member: 

/usr/bin/systemctl stop sessionmgr-27720
/usr/bin/systemctl start sessionmgr-27720
Step 6

Wait for the recovery to finish.

Manage Disks to Accommodate Increased Subscriber Load

If you need to prepare CPS for an increased number of subscribers (> 10 million), you can clone and repartition the sessionmgr disks as per your requirement.

Clone Sessionmgr01 VM

Downtime: No downtime

Before you begin

  • Before disk repartition, clone sessionmgr01. This step is optional but to reduce the risk of losing the data during disk repartitioning, the customer can take the backup of sessionmgr01 VM. If the customer does not have enough space to take the backup this step can be ignored.

  • Blade with enough space to hold cloned image of sessionmgr01.

Procedure

Step 1

Login to vSphere Client on sessionmgr01 blade with administrator credentials.

Step 2

Right-click sessionmgr01 and select Clone > Choose appropriate inventory in which blade resides > Choose the blade with enough space to hold sessionmgr01 image > Next > Next > Finish.

Step 3

Cloning starts. Wait for it to finish the process.

Disk Repartitioning of Sessionmgr01 VM

Downtime: During this procedure Sessionmgr01 is shut down 2 times. Estimate approximately 30 minutes of downtime for sessionmgr01.

CPS continues to operate using the other sessionmgr02 while sessionmgr01 is stopped as part of procedure.

Before you begin

None

Procedure

Step 1

Login to sessionmgr01 as a root user.

Step 2

The following commands may be executed to help identify which partition requires additional space. 

 synph# df -h/synph
synphFilesystem                       Size  Used Avail Use% Mounted on/synph
synph/dev/mapper/vg_shiprock-lv_root  7.9G  1.5G  6.0G  20% //synph
synphtmpfs                            1.9G     0  1.9G   0% /dev/shm/synph
synph/dev/sda1                        485M   32M  428M   7% /boot/synph
synph/dev/mapper/vg_shiprock-lv_home  2.0G   68M  1.9G   4% /home/synph
synph/dev/mapper/vg_shiprock-lv_var    85G   16G   65G  20% /var/synph
synphtmpfs                            2.3G  2.1G  172M  93% /var/data/sessions.1/synph
synph/synph
synph# pvdisplay/synph
synph  --- Physical volume ---/synph
synph  PV Name               /dev/sda2/synph
synph  VG Name               vg_shiprock/synph
synph  PV Size               99.51 GiB / not usable 3.00 MiB/synph
synph  Allocatable           yes (but full)/synph
synph  PE Size               4.00 MiB/synph
synph  Total PE              25474/synph
synph  Free PE               0/synph
synph  Allocated PE          25474/synph
synph  PV UUID               l3Mjox-tLfK-jj4X-98dJ-K3c1-EOel-SlOBq1/synph
synph/synph
synph# vgdisplay/synph
synph--- Volume group ---/synph
synph  VG Name               vg_shiprock/synph
synph  System ID             /synph
synph  Format                lvm2/synph
synph  Metadata Areas        1/synph
synph  Metadata Sequence No  5/synph
synph  VG Access             read/write/synph
synph  VG Status             resizable/synph
synph  MAX LV                0/synph
synph  Cur LV                4/synph
synph  Open LV               4/synph
synph  Max PV                0/synph
synph  Cur PV                1/synph
synph  Act PV                1/synph
synph  VG Size               99.51 GiB/synph
synph  PE Size               4.00 MiB/synph
synph  Total PE              25474/synph
synph  Alloc PE / Size       25474 / 99.51 GiB/synph
synph  Free  PE / Size       0 / 0   /synph
synph  VG UUID               P1ET44-jiEI-DIbd-baYt-fVom-bhUn-zgs5Fz/synph

  • (df -h): /var is /dev/mapper/vg_shiprock-lv_var. This is equivalent to device /dev/vg_shiprock/lv_var.

  • (pvdisplay): vg_shiprock (used by lv_var which is /var) is on /dev/sda2.

Step 3

Execute the fdisk command to check the disk size. 

# fdisk -l /dev/sda 
 
Disk /dev/sda: 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: 0x0008dcae 
 
   Device Boot      Start         End      Blocks   Id  System 
/dev/sda1   *           1          64      512000   83  Linux 
Partition 1 does not end on cylinder boundary. 
/dev/sda2              64       13055   104344576   8e  Linux LVM
Step 4

Power down the Virtual Machine.

# shutdown -h now

Note 

If cloning is not possible because of space limitation on Blade, backup of sessionmgr01 VM can be taken by saving OVF of sessionmgr01 VM to local storage like Laptop, Desktop. (Both cloning and OVF backup are optional steps, but either one of them is highly recommended.)

Step 5

Log in using the VMware vSphere Client as an administrator (e.g. root) to the ESXi host which has your Linux Virtual Machine on it.

Step 6

Right-click on the Virtual Machine and select Edit Settings > Click Hard Disk 1 > Increase the Provisioned Size of the Hard Disk.

Step 7

Power ON the Virtual Machine.

Step 8

Login (ssh) to the Virtual Machine as root user.

Step 9

Confirm that disk space has been added to the /dev/sda partition. 

# fdisk -l /dev/sda 
 
Disk /dev/sda: 70.5 GB, 79529246720 bytes 
255 heads, 63 sectors/track, 9668 cylinders 
Units = cylinders of 16065 * 512 = 8225280 bytes
Step 10

Execute the following commands (Bold Characters indicates actual inputs from user (all of them are in lower case). 

# fdisk /dev/sda 
The number of cylinders for this disk is set to 7832. 
There is nothing wrong with that, but this is larger than 1024, 
and could in certain setups cause problems with: 
1) software that runs at boot time (e.g., old versions of LILO) 
2) booting and partitioning software from other OSs 
   (e.g., DOS FDISK, OS/2 FDISK) 
Command (m for help): p  
Disk /dev/sda: 64.4 GB, 64424509440 bytes 
255 heads, 63 sectors/track, 7832 cylinders 
Units = cylinders of 16065 * 512 = 8225280 bytes 
   Device Boot      Start         End      Blocks   Id  System 
/dev/sda1   *           1          13      104391   83  Linux 
/dev/sda2              14        7179    57560895   8e  Linux LVM 
Command (m for help): d  
Partition number (1-4): 2  
Command (m for help): n  
Command action 
   e   extended 
   p   primary partition (1-4) 
p  
Partition number (1-4): 2  
First cylinder (14-7832, default 14):  [press enter]  
Using default value 14 
Last cylinder +sizeM/+sizeK (14-7832,default 7832): [press enter] 
Using default value 7832 
Command (m for help): t  
Partition number (1-4): 2  
Hex code (type L to list codes): 8e  
Changed system type of partition 2 to 8e (Linux LVM) 
Command (m for help): w  
The partition table has been altered! 
Calling ioctl() to re-read partition table. 
WARNING: Re-reading the partition table failed with error 16: Device or resource busy. 
The kernel still uses the old table. 
The new table will be used at the next reboot. 
Syncing disks.
Step 11

Reboot the sessionmgr01 VM by executing the following command:

# reboot

This ensures that the new setting match up with the kernel.

Step 12

After reboot, execute following command: 

# pvresize /dev/sda2
Physical volume "/dev/sda2" changed
1 physical volume(s) resized / 0 physical volume(s) not resized
Step 13

Confirm that the additional free space is added in sessionmgr VM. 

# vgdisplay 
  --- Volume group --- 
  VG Name               vg_shiprock 
  System ID              
  Format                lvm2 
  Metadata Areas        1 
  Metadata Sequence No  5 
  VG Access             read/write 
  VG Status             resizable 
  MAX LV                0 
  Cur LV                4 
  Open LV               4 
  Max PV                0 
  Cur PV                1 
  Act PV                1 
VG Size             129.51 GiB  
PE Size              4.00 MiB  
Total PE             32974 
Alloc PE / Size     25474 / 99.51 GiB 
Free PE / Size     7500 / 30.00 GB 
VG UUID              pPSNBU-FRWO-z3aC-iAxS-ewaw-jOFT-dTcBKd
Step 14

Verify that the /var partition is mounted on /dev/mapper/vg_shiprock-lv_var. 

#df -h 
Filesystem           Size Used Avail Use% Mounted on 
/dev/mapper/vg_shiprock-lv_root 
						18G 2.5G    15G 15% / 
/dev/mapper/vg_shiprock-lv_home 
						5.7G 140M 5.3G   3% /home 
/dev/mapper/vg_shiprock-lv_var 
						85G   16G   65G   20% /var 
/dev/sda1              99M   40M   55M  43% /boot 
tmpfs                  16G     0   16G   0% /dev/shm 
tmpfs                 8.0G  1.1G  7.0G  14% /data/sessions.1
Step 15

Extend /var partition to take up additional free space. 

#lvextend -l +100%FREE /dev/mapper/vg_shiprock-lv_var
 Extending logical volume lv_var to 120.00 GB
 Logical volume lv_var successfully resized
Step 16

Check the newly added space in /dev/mapper/vg_shiprock-lv_var.

# lvdisplay
Step 17

Add space to VM file system. 

# resize2fs /dev/mapper/vg_shiprock-lv_var
resize2fs 1.39 (29-May-2006)
Filesystem at /dev/mapper/vg_shiprock-lv_var is mounted on /var; on-line resizing required
Performing an on-line resize of /dev/mapper/vg_shiprock-lv_var to 6553600 (4k) blocks.
The filesystem on /dev/mapper/vg_shiprock-lv_var is now 6553600 blocks long.
Step 18

Check the increased size of /var partition. 

# df -h 
Filesystem            Size  Used Avail Use% Mounted on 
/dev/mapper/vg_shiprock-lv_root 
                       23G  2.1G   20G  10% / 
/dev/mapper/vg_shiprock-lv_home 
                      5.7G  140M  5.3G   3% /home 
/dev/mapper/vg_shiprock-lv_var 
                      130G   16G   95G  12% /var 
/dev/sda1              99M   40M   55M  43% /boot 
tmpfs                 2.0G     0  2.0G   0% /dev/shm