January 2016 - The Practical Administrator

NetApp PowerShell Toolkit: Aggregate Overcommitment Report

2016-01-202017-09-27 by Andrew Sullivan

I recently encountered a posting on the NetApp Community asking about, among other things, allocated capacity for an aggregate. As you can see in my response, I created a quick scriptlet which displays the information regarding total volume capacity allocated, but this is only part of the potentially thin provisioned capacity. LUNs can also be thin provisioned inside the volume. Additionally, some may find how much overcommitment exists with no storage efficiency applied as well (this can help with IOPS density calculations, for example).

To address this, I created a function which will display the total, used, saved, and committed capacity for an aggregate…

Show Overcommitment for Non-Root Aggregates

Get-NcAggr | ?{ $_.Name -notlike "*root" } | Get-NcAggrOvercommitReport | Format-Table -AutoSize

1	Get-NcAggr \| ?{ $_.Name -notlike "*root" } \| Get-NcAggrOvercommitReport \| Format-Table -AutoSize

Show Aggregates Which Have Overcommitment > 200%

Get-NcAggr | ?{ $_.Name -notlike "*root" } | Get-NcAggrOvercommitReport | ?{ $_.CommittedPercent -gt 200 }

1	Get-NcAggr \| ?{ $_.Name -notlike "*root" } \| Get-NcAggrOvercommitReport \| ?{ $_.CommittedPercent -gt 200 }

PowerShell: Convert String To Array

2016-01-182017-09-27 by Andrew Sullivan

In December I had fun solving the “riddles” at Advent Of Code and a large number of them (starting with number 1) had strings for input that needed to be parsed. So, posting this for myself, cause I can never remember it….

Convert a string to an array of single characters

# the input string
$string = "This is a string"

# convert it to a character array
$array = $string.ToCharArray()

# now we can iterate like any array
foreach ($char in $array) {
    $char
}

# the input string

$string = "This is a string"

# convert it to a character array

$array = $string.ToCharArray()

# now we can iterate like any array

foreach ($char in $array) {

$char

}

The output:

Convert a string into an array of words

# the input string
$string = "This is a string"

# create an array from an arbitrary separator, in this case a space
$array = $string.split(" ")

# this will also work
$array = $string -split " "

# the input string

$string = "This is a string"

# create an array from an arbitrary separator, in this case a space

$array = $string.split(" ")

# this will also work

$array = $string -split " "

Convert a string based on arbitrary characters

This also works with regular expressions…

$string = "a1b2c3d4e5f6"

# split on numbers - remember, this will remove the numbers from the output
$string -split "\d"

# split on letters - this will remove the letters from the output
$string -split "\D"

$string = "a1b2c3d4e5f6"

# split on numbers - remember, this will remove the numbers from the output

$string -split "\d"

# split on letters - this will remove the letters from the output

$string -split "\D"

cDOT Environment Monitoring Using PowerShell

2016-01-072017-09-27 by Andrew Sullivan

Environmental information, for example temperature, fan speed, etc., provide critical information about the health of your clustered Data ONTAP system. Depending on your version of ONTAP, you can query the environmental information different ways to find out the status.

With ZAPI version 1.21 and above (cDOT 8.2.3+) the environment-sensors-get-iter API exists, which makes it excessively easy to collect environmental information about the controllers. We can take the same approach with environmental sensors as performance information:

cDOT Performance Monitoring Using PowerShell

2016-01-052017-09-27 by Andrew Sullivan

Performance monitoring is a complex topic, but it’s something that is vital to the successful implementation and maintenance of any system. In the past I’ve had several posts about using Perl for gathering performance statistics from a 7-mode system (using ONTAP 7.3.x, which is quite old at this point), so I thought it might be a good time for an update.

I originally documented some of this information in a response on the NetApp Community site. This post expands on that a bit and documents it externally.

The NetApp PowerShell Toolkit has three cmdlets which we can use to determine what objects, counters, and instances are available, and a fourth cmdlet to actually collect the data.