networking - How much network latency is "typical" for east - west coast USA? - Server Fault

networking - How much network latency is "typical" for east - west coast USA? - Server Fault: the actual math is: 3000 mi / c = 16.1ms

So, light can travel from east coast USA to west coast USA in just over 16ms.

minimum PING response:
- it has to come back too.
- it is traveling over glass fiber, not in a vacuum
- many other components can introduce latency.

a 40 something ms response is the best it's ever going to get.

networking - How much network latency is "typical" for east - west coast USA? - Server Fault

networking - How much network latency is "typical" for east - west coast USA? - Server Fault: In a vacuum a photon can travel the equator in roughly 134 ms. The same photon in glass would take around 200 ms. A 3,000 mile piece of fiber has 24 ms. of delay without any devices.

Mapped Drive Connection to Network Share May Be Lost

Mapped Drive Connection to Network Share May Be Lost: Mapped Drive Connection to Network Share May Be Lost

Cisco IOS supported protocols

Supported IP Protocols in Cisco IOS Software

These IP protocols are supported by Cisco IOS Software:

· 1 – ICMP

· 2 – IGMP

· 3 – GGP

· 4 – IP in IP encapsulation

· 6 – TCP

· 8 – EGP

· 9 – IGRP

· 17 – UDP

· 20 – HMP

· 27 – RDP

· 41 – IPv6 in IPv4 tunneling

· 46 – RSVP

· 47 – GRE

· 50 – ESP

· 51 – AH

· 53 – SWIPE

· 54 – NARP

· 55 – IP mobility

· 63 – any local network

· 77 – Sun ND

· 80 – ISO IP

· 88 – EIGRP

· 89 – OSPF

· 90 – Sprite RPC

· 91 – LARP

· 94 – KA9Q/NOS compatible IP over IP

· 103 – PIM

· 108 – IP compression

· 112 – VRRP

· 113 – PGM

· 115 – L2TP

· 120 – UTI

· 132 – SCTP

Cisco solutions

http://www.cisco.com/en/US/netsol/ns820/networking_solutions_program_h

Flexpod

http://docwiki.cisco.com/wiki/Shared_Storage_Considerations

Exchange: Report mailboxes and size

get-mailboxstatistics -server PRIEXS01CCR | ft DisplayName, TotalItemSize > mailboxes.txt

Cisco console

Go from the aux port on the router to the console port on the switch with a rollover cable. Do a show line on the router. The aux port is probably 2001. Telnet to the router ip port 2001 and it will be the switch console port.

Esxi

I don't understand why the service console had to go away.  Now it is a mess of confusing junk to get things done.
TIP
When you SSH to a ESXi host, you can get the console by typing: dcui

Excessive VMWare vcenter notifications

Problem: A bunch of “check new notifications” tasks are “queued” in vCenter Solution: From the vCenter server console, restart “vmware vcenter update manager service”

VMWare io stats

VMWare 4 Statistics:  Get iops per vm on VMFS datastores

################################################################################
# GatherIOPS.ps1
#
# Thanks to:
# Curtis Salinas, # http://virtualcurtis.wordpress.com, October 2010 
################################################################################
# 
# Given a list of datastore names in file named store.txt & a vCenter Server FQDN,
# this script will return a table of IOPS by every virtual machine
# on those datastores over a 60 minute interval. This data
# is output to the PowerShell screen and to a csv file
#
#Run the following to create credentials file with password to username that is 
#defined by $username:
#read-host -prompt "enter password" -assecurestring | convertfrom-securestring | out-file cred.txt
#
#$username is a local account on each host
#
################################################################################


#param($datastores, $server, $numsamples)

$today = get-date
$day = $today.Day
$mth = $today.Month
$year = $today.Year
$hour = $today.Hour
$min = $today.Minute
$sec = $today.Second
$date = "$year-$mth-$day-$hour$min$sec"

$outfile = "IO-VM-$date.CSV"

$datastores = get-content .\stores.txt
$server = "vcs01.domain.com"
$numsamples = 180
 # number of samples = x time
 # 180 = 60min
 # 90 = 30min
 # 45 = 15min
 # 15 = 5min
 # 3 = 1min
 # 1 = 20sec (.33 min)

$username = "root"
$password = get-content cred.txt | convertto-securestring
$credentials = new-object -typename System.Management.Automation.PSCredential -argumentlist $username,$password


# add VMware PS snapin
if (-not (Get-PSSnapin VMware.VimAutomation.Core -ErrorAction SilentlyContinue)) {
    Add-PSSnapin VMware.VimAutomation.Core
}

# connect vCenter server session
Connect-VIServer $server -NotDefault -WarningAction SilentlyContinue | Out-Null


# function to get iops for a vm on a particular host
function GetAvgStat($vmhost,$vm,$ds,$samples,$stat){

 # connect to host
 connect-viserver -server $vmhost -credential $credentials -NotDefault -WarningAction SilentlyContinue | Out-Null
 
 # identify device id for datastore
 $myDatastoreID = ((Get-Datastore $ds -server $vmhost) | Get-View).info.vmfs.extent[0].diskname
 
 # gather iops generated by vm
 $rawVMStats = get-stat -entity (get-vm $vm -server $vmhost) -stat $stat -maxSamples $samples
 $results = @()
 
 foreach ($stat in $rawVMStats) {
  if ($stat.instance.Equals($myDatastoreID)) {
   $results += $stat.Value
  }
 }
 
 $totalIOPS = 0
 foreach ($res in $results) {
  $totalIOPS += $res 
 }
 
 return [int] ($totalIOPS/$samples/20)
}

$IOPSReport = @()

$i = 0
$dstotal = $datastores.length + 1
foreach ($datastore in $datastores) {
  write-progress -id 1 -activity "Gathering IOPS Data" -status "% Datastores Complete" -percentcomplete (($i / $dstotal)*100)
  
  # Grab datastore and find VMs on that datastore
  $myDatastore = Get-Datastore -Name $datastore -server $server
  $myVMs = Get-VM -Datastore $myDatastore -server $server | Where {$_.PowerState -eq "PoweredOn"}
  
  if ($myVMs -eq $null) { continue } #go to next in foreach if no VM's listed
  
  # Gather current IO snapshot for each VM
  $dataArray = @()
  
  $j = 0
  $vmtotal = $myVMs.length + 1
  foreach ($vm in $myVMs) {
   write-progress -id 2 -parentID 1 -activity "Gathering IOPS Data" -status "% VMs in $datastore" -percentcomplete (($j / $vmtotal)*100)
   $data = ""| Select "Time", "VM", "Interval (minutes)", "Avg Write IOPS", "Avg Read IOPS", "Total IOPS"
   $data."Time" = $date
   $data."VM" = $vm.name
   $data."Interval (minutes)" = ($numsamples*20)/60
   $data."Avg Write IOPS" = GetAvgStat -vmhost $vm.host.name -vm $vm.name -ds $datastore -samples $numsamples -stat disk.numberWrite.summation
   $data."Avg Read IOPS" = GetAvgStat -vmhost $vm.host.name -vm $vm.name -ds $datastore -samples $numsamples -stat disk.numberRead.summation
   $data."Total IOPS" = $data."Avg Write IOPS" + $data."Avg Read IOPS"
   $dataArray += $data
   $j++
   }
  
  # Do something with the array of data
  $IOPSReport += $dataArray
  
  $i++

}

$IOPSReport
$IOPSReport | Export-CSV $outfile -NoType

VMWare Statistics

esxtop has "commands per second" metric - what is that?

IOPS = Input/Output Operations Per Second

• Within esxtop this would be the outcome of “Number of Read commands(READS/s) + Number of Write commands(WRITES/s)”

CMDS/s = Total commands per second

• Within esxtop this includes any command(for instance SCSI reservations) and not necessary only read/write IOs