Thursday, August 22, 2013

Commands to monitor snapshot deletion in ESX 2.5/3.x/4.x and ESXi 3.x/4.x/5.x (1007566)

ESX 3.5/4.x and ESXi 4.1/5.x

To monitor directories during snapshot deletion in ESX 3.5/4.x and ESXi 4.1/5.x: 

  1. Log in as root to the ESX host using SSH. For more information, see Connecting to an ESX host using a SSH client (1019852) or Using Tech Support Mode in ESXi 4.1 and ESXi 5.0 (1017910)
  2. Navigate to the virtual machine directory containing vmdk virtual disk files.
  3. List files in the directory by executing:

    # ls -al
  4. Determine any VM_NAME-00000#.vmdk or VM_NAME-00000#-delta.vmdk snapshot files. Look for numbered files following the hyphen(-) in the name.
  5. To monitor the VMDK snapshot and base disks which are currently being updated use the following watch command:

    # watch -d 'ls -luth | grep -E "delta|flat"'

    -d  highlights the differences between successive updates
    t   sorts by modification time
    l   shows a long listing which displays additional file information    sorts by and shows access time
    h   prints sizes in a readable format like 1K 234M 2G
    You can also run the following command to monitor the time stamp update of the base disks to confirm if the process is working or not.

    ls -lrt |grep -E "flat|delta"

    This command monitors the contents of a directory and displays files by their modification date.

    Note: In ESX 3.5 and 4.0 (pre Update 2) the snapshot delta files will be written to the previous snapshot delta file and so on and are finally written to the base disk (flat). In ESX/ESXi 4.0 Update 2 and later the process works differently in that the data in snapshots (deltas) are written directly to the base disk (flat). For more information on the snapshot process, see Understanding virtual machine snapshots in VMware ESXi and ESX (1015180) and Consolidating snapshots (1007849).

    If there are more than 10 snapshots, use this command to monitor the snapshot commit process and to prevent the screen from filling with too many files:

    # while true;do date;ls -lht *vmdk|head -10;echo ________;sleep 3;done

    Note: You can quit the consolidation process monitoring by pressing Ctrl + C. 

Thursday, August 15, 2013

Object Type in vCenter Operation Manager

vCenter Operations Manager uses specific icons so that you can distinguish between virtual machines, ESX hosts, and other objects in the inventory. All these objects will be monitored via inventory pane in vCOPS

Monday, August 12, 2013

Unable to maximize the virtual machine console window after it has been minimized to the Windows taskbar (1033948)

This is a known issue. This issue only occur when all of the conditions in the Symptoms are met.
You do not encounter this issue when:
  • The Windows system where your vSphere Client is installed is not configured to group similar taskbar buttons.
  • If the virtual machine in which you are launching a virtual machine console does not have an associated snapshot.
To work around this issue, perform one of these options:
  • Deselect the option Group similar taskbar buttons:
    1. On the Windows system running the vSphere Client, right-click the Windows taskbar.
    2. Click Properties.
    3. Deselect Group similar taskbar buttons.
    4. Click Apply > OK.
  • Remove the snapshot from the virtual machine whose console is stuck in a minimized state on the Windows taskbar: 
    1. Using the vSphere Client, right-click on the virtual machine and choose Snapshot > Snapshot Manager.
    2. Remove the snapshot, by choosing to Go To or Delete.

Thursday, August 1, 2013

Snapshot Limitations

Snapshots can affect virtual machine performance and do not support some disk types or virtual machines configured with bus sharing. Snapshots are useful as short-term solutions for capturing point-in-time virtual machine states and are not appropriate for long-term virtual machine backups.

VMware does not support snapshots of raw disks, RDM physical mode disks, or guest operating systems that 
use an iSCSI initiator in the guest.
Virtual machines with independent disks must be powered off before you take a snapshot. Snapshots of
 powered-on or suspended virtual machines with independent disks are not supported.
Snapshots are not supported with PCI vSphere Direct Path I/O devices.
VMware does not support snapshots of virtual machines configured for bus sharing. If you require bus sharing, 
consider running backup software in your guest operating system as an alternative solution. If your virtual 
machine currently has snapshots that prevent you from configuring bus sharing, delete (consolidate) the 
Snapshots provide a point-in-time image of the disk that backup solutions can use, but Snapshots are not 
meant to be a robust method of backup and recovery. If the files containing a virtual machine are lost, its 
snapshot files are also lost. Also, large numbers of snapshots are difficult to manage, consume large amounts
 of disk space, and are not protected in the case of hardware failure.
Snapshots can negatively affect the performance of a virtual machine. Performance degradation is based on
 how long the snapshot or snapshot tree is in place, the depth of the tree, and how much the virtual machine 
and its guest operating system have changed from the time you took the snapshot. Also, you might see a delay
 in the amount of time it takes the virtual machine to power-on. Do not run production virtual machines from 
snapshots on a permanent basis.