Yellow Bricks

by Duncan Epping

service console

Command line tips and tricks #2

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Three totally different command line tips/tricks this time:

  1. Dump a specific disk via the VCB Proxy monolithic(1 big chunk):
    Open a cmd and goto your VCB installation path
    “vcbexport.exe -M 1 -d test01.vmdk -s TestVM/TestVM.vmdk”
  2. Any swapping going on or more info on memory usage in general:
    Open a putty sesion to your ESX box
    “watch -n 1 cat /proc/vmware/sched/mem”
  3. Reinitialize the VirtualCenter Database:
    Stop the service
    Start vpxd.exe with the option “-b”
    CAUTION, this will wipe out the entire database, this is a last resort!

Command line tips and tricks #1

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Because I will be posting less in the upcoming weeks about problems I face at customer sites I will try to post some cool command-line tip or trick I discovered or picked up somewhere….

open ESX console ,via putty and type the following
vm-support -x
result: all the VMID’s also known as World ID’s,

And if you’re colleagues hardly ever clean up their snapshots:

find /vmfs/volumes -iname “*delta.vmdk”
result: every delta file gets listed, including the unregistered and/or orphaned snapshots ones!

ESX 3i backdoor

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According to this new KB article there’s a backdoor for ESX3i:

  1. Log in to your ESX Server 3i at the console.
  2. Press Alt+F1 to switch to the console window.
  3. Enter unsupported to start the Tech Support Mode login process. Note that no text will appear on the console window.
  4. Enter the password for the root user. Tech Support Mode is now active.
  5. Complete tasks in Tech Support Mode.
  6. Enter the command exit to exit Tech Support Mode.
  7. Press Alt+F2 to return the server to DCUI mode.

For more info check the KB article. I will be checking out this feature over the next couple of days to see what’s possible in this mode.

VCB: I forgot all about “automount disable” what now?

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Before installing VCB and connecting the proxy host to the SAN you should disable automount via diskpart(cmd, diskpart, automount disable, automount scrub). When you don’t disable automount Windows will signature all “incoming” disks. When this happens the VMware hosts will not recognize the VMFS volumes anymore. But fortunately you can re-label the luns as VMFS.

Check with “fdisk -lu” what the current ID value is of the volumes, it’s “SFS” if Windows wrecked it. Write all the devices down and label them again as VMFS:
fdisk /dev/sd? (? the letter for that specific volume)

p
d
n
p
1
default
t
fb
X
b
1
128 (disk alignment, check your SAN manual for the correct value, 128 is correct in most cases…)
W

Now rescan the HBA devices, esxcfg-rescan vmhba0 etc etc.

Checking for snapshots, html email report!

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When reading the VMTN forum I stumbled upon a topic about checking the VMFS for snapshots. Besides snaphunter by Xtravirt, which is an excellent script, there isn’t much out there. You can check the VirtualCenter database for snapshots but this way you would not notice the orphaned snapshots. (Orphaned snapshot occur when the vmsd file gets corrupted.) A couple of months before Xtravirt posted their script I wrote my own snapshot checking script named snapcheck.sh. [Read more…] about Checking for snapshots, html email report!