Ok, so I wanna be a VCDX.. and I’ll let you all know how I’m getting on..
Firstly, I’m already a VCAP-DCD5 and there’s not much more to add than whats already out there on the web. If you do however have access to the VMware partner portal, it’s well worth going through some of the competency courses.
I’ve taken the VCAP-DCA5 recently and this is a post on that experience.. (I haven’t got my results yet)
It was pretty scary! It’s the first time I have ever taken a live lab exam.. and I would definitely give it a thumbs up in providing employers a better gauge on a prospective employee’s skill and experience than a VCP. ( Of which I was quite happy to be, for a long time =) ).
If there is one ultimate tip I could give, and that you’re testing centre is not situated in the US is: try and get an exam time out of business hours, though this theory has not been proven as far as I know..
This is because of the latency I experienced from keystroke to screen display being horrendous from Singapore. Just switching views inside the vSphere client would take approx. 15-20secs. You might think thats not too bad if theres only 26 questions, but there are multiple tasks in each question of which each task may need different screens to complete. Lets just say on average its 10 screen changes per task and 10 tasks per question, thats equates 42 minutes of waiting time on an exam time frame of 4 hours. You’ve lost nearly 18% of you’re time.
Still I was quite well prepared, with most question do-able without too many hesitations or excessive screen switching, yet I could only get to question 21. So fingers crossed.
I’m on a Mac, so the other tip is get used to a normal keyboard preferably the same one as the testing centre.
Tip 3: As all the other guys have blogged.. Get Practising! Build that lab, with auto deploy etc. I did it under an hour so I’m sure you could too.
My study notes are below, they’re a bit verbose as all I wanted to get to grips with, was the execution rather than the outcomes and reasons why etc..
I’ve emailed VMware of my dissatisfaction, and they have kindly responded with a free retake if I have not passed. That’s all good, but I’ld rather not have to sit through another 4 hours and experience the same issue. And I’m definitely not well off enough to fly to the US for the exam.
Hey VMware, just a thought.. Can we use PCoIP instead of RDP?
So here are my notes, go execute!
Find a file
find / -name ‘name-of-file’
ready time ms / 20000 = % of time waiting for cpu (ready time %)
memory granted - memory allocated
Average memory active - amount of memory estimated to be used on recently touched memory pages.
Consumed memory - amount of memory estimated to be reserved by guest OS – minus memory sharing via TPS
check if VMware tools is installed via esxtop (J* option)
If you see a number above 1 it means commands are taking over 60 seconds to complete and are then aborted.
is as bad as commands aborted
use ‘vDisk Informer’ to check partition alignments
**vscsiStats shows latency for the virtual SCSI device
‘vscsiStats -l’ to list out vms and their world id
‘vscsiStats -s -w [world id]‘ to start collecting information
‘vscsiStats -p latency’ to show histogram on latency
‘vscsiStats -x’ to stop collecting
‘vscsiStats -r’ to clear all the counters for next time.
‘ioLength‘ will help with block size
‘seekDistance‘ will help with sequential or random io
Show all filesystems mounted or unmounted
esxcli storage filesystem list
Re-attach storage device
esxcli storage core device detached list
esxcli storage core device set -d naa.XXX –state=on
esxcli storage nmp device list
esxcli storage nmp device set –device t10.dsfsdf –psp VMW_PSP_FIXED
esxcli storage nmp device set –device t10.E4143500000000000000000010000000F011000000000100 –psp VMW_PSP_RR
create vmfs datastore
vmkfstools –createfs vmfs5 –blocksize 1m device_id:p
Grow VMFS datastore
vmkfstools –growfs /vmfs/devices/disks/disk:id1 /vmfs/devices/disks/disk:id1
add nfs mount
esxcfg-nas -a -o 192.168.1.100 -s /raid0/data/Software Software
VMM - Virtual Machine Monitor
cat ../../‘vmname’/vmware.log | grep “MONITOR” will show whether the VM is using HW virtualisation
vmkfstools -c 8G -a lsilogic /vmfs/vol/datastore/vm/vmdisk.vmdk -d thin/zeroedthick/
vi fast pass
vifp addserver esx01.vmpact.int
connect to server
resxtop –server ipaddress –user root
‘f’ to choose field options
‘o’ to display fields in order that you wish, upper case to move up, lower case to move down.
‘W’ to save configuration of esxtop
‘esxtop -c .filename‘ to open saved esxtop configuration DONT forget FULL STOP in front of filename!
esxtop batch mode
-b batch mode
-d collection interval in seconds
-n number of iterations to collect
esxtop -b -d 5 -n 100 > “output file destination”
esxcli software vib list to list out software
esxcli software vib install -n package.pkg to install package
esxcli software vib install -d UNCpath
Change to strong password
enable snmp on ESXi, you have to do it via vMA (SNMP default port = 162 UDP)
Run command to configure SNMP communities to send traps
vicfg-snmp –server 192…… –username root -c ‘community,string,separated,by,commas’
Run vicfg-snmp –target with the target address, port number, and community
vicfg-snmp -t ‘target.example.com@163/public‘
Run vicfg-snmp –show to display info
Run vicfg-snmp –enable to enable snmp agent to send traps
configure SNMP agent for polling and enable
vicfg-snmp –server 192…… –username root -c ‘communitystring’ -t target.example.com@163/public –enable
configure SNMP port
vicfg-snmp –server 192…… –username root -p
SYSLOG (Default UDP 514)
keep twenty rotations before overwriting the oldest log
esxcli <conn_options> system syslog config set –default-rotate=20
Set the rotation policy for VMkernel logs to 10 rotations, rotating at 2MB.
esxcli <conn_options> system syslog config logger set –id=vmkernel –size=2048 –rotate=10
Save the local copy of logs to /scratch/mylogs and send another copy to the remote host.
esxcli <conn_options> system syslog config set –logdir-unique true –loghost=’tcp://myhost.mycompany.com:1514′ –logdir=’/scratch/mylogs’
after config change, reload syslog daemon
esxcli <conn_options> system syslog reload
list firewall service sshClient —-stop here for full list
esxcli network firewall ruleset list –ruleset-id sshClient
enable a firewall service
esxcli network firewall ruleset set –ruleset-id sshClient –enabled true
limit networks and IP address for connections
esxcli network firewall ruleset set –ruleset-id sshClient –allowed-all false
Add networks for connections
esxcli network firewall ruleset allowedip add –ruleset-id sshClient –ip-address 192.168.1.0/24
Check network conn list
esxcli network firewall ruleset allowedip list –ruleset-id sshClient
List NTP servers
vicfg-ntp <conn options> -l
Add NTP servers
vicfg-ntp <conn options> -a
Stop NTP service
vicfg-ntp <conn options> -s
Start NTP service
vicfg-ntp <conn options> -r
Create User and add to role admin
vicfg-user <conn options> -e user -o add -l username -p password -r role
vicfg-user <conn options> -e group -o add -d groupname
Add user to group
vicfg-user <conn options> -e user -o modify -l tramp -g groupname
Generate New Certificates
/etc/vmware/ssl - location of SSL certificates
/sbin/generate-certificates or copy CA certificates to same location.
from vMA vifs <conn opt> –put rui.crt /host/ssl_cert
vifs <conn opt> –put rui.key /host/ssl_key
/etc/init.d/hostd restart - needs reboot
Configure SSL timeouts
Find the <vmcore> and <http> and <ssl> tags, they exist already.
Storage Perf Analysis & monitorinsg
Storage Queues affect Perf
Scalable Storage Perf
Changing Queue Depth QLogic/Emulex
Setting the Max Outstanding Disk Requests per VM
Controlling LUN Queue Depth Throttling in ESXi
VMFS deep dive & BP
VMFS Sizing for Max Performance