In this
video, we are going to talk about the different methods
of performing a backup of your PI Data Archive
as well as the components of a comprehensive backup strategy.
In general in your PI System, your users
connect to your PI Data Archive to retrieve historical or
realtime time series data. You may have
previously heard the PI Data Archive referred to as the PI Server.
In general, a backup is a copy of your
information in case the original is damaged or lost.
When it comes to your PI Data Archive,
the backup is a copy of both your data or your archive files
themselves as well as the configuration information that is
necessary to restore your PI Data Archive to its
exact customized configuration.
A backup works such that you copy your configuration information and
data to a specified location which can then be
used to restore your system on a new machine.
Let's take a look in more detail as to what this entails.
In my PI Data Archive, I have several
components that are important and custom to my configuration.
For instance, I have my PI Data Archive
installation directory itself which holds all of the configuration
information for my system. I also have a directory
of my archive files which is where my time series
data is stored. Finally, I have my
client directories including the configuration of interfaces
that are installed locally on my PI Data Archive.
I want to save all of these particular
settings on my system in order to restore it at a future point.
Therefore we recommend taking a backup of our
PI Data Archive where we will copy all of these
files and store them in a separate specified location.
In order to minimize the impact on the
performance of our running PI Data Archive during the backup
process, we recommend using a script provided
with your PI Data Archive installation to perform a
backup locally on the PI Data Archive first.
We'll then also talk about saving a
copy of these files in a remote location as well.
On our PI Data Archive itself, we recommend
performing a backup and saving the files on a dedicated disk drive.
For instance if my PI Data
Archive is installed on my C drive and my
archive files are held on my D drive, then if I stored my
backup on either of my C or my D drive, I
would have no protection in the case of disk failure on either of those drives,
as I would lose both the original files and backups.
However, if I have my backups
stored on a dedicated disk drive,
I know in the event of disk failure on either of the drives that holds
my PI Data Archive, or
my archive themselves, I'll still have a safe copy of my
data on my dedicated drive for my
backups. However, you may also
encounter a situation where there isn't just disk
failure on a particular drive. You may experience
hardware failure on the entire PI Data Archive machine itself.
In this case, even though our backups are on a dedicated
drive, we will also lose our backup files as
they are on the same machine. For situations like
this, we recommend including in your comprehensive backup
strategy a remote backup of your PI Data Archive.
This can be done on a remote
medium such as another computer, disk or any other storage
device. We recommend that you work with your
IT department to include this remote* backup directory as
part of your full backup strategy.
However if your IT department is unavailable to
help with this, there is a script included with your PI Data
Archive installation that can be configured to perform the
remote backup as well. In this case,
the same configuration information and files will be
copied to a remote medium. That way if there is a hardware
failure on the PI Data Archive machine itself,
we will be able to restore our system on a new
machine using the files from our remote backup location.
However going through the process of
taking a local backup on our PI Data Archive
as well as copying that local backup directory to a remote
medium sounds like a tedious process to perform habitually.
Therefore we have included a method of
creating a scheduled automated task to perform this entire
backup procedure for you. However
if the automated task runs and copies the entire
PI Data Archive directory and all of your archive files themselves
every time it runs, it's performing a lot more work than it needs to.
For this reason,
automated PI Data Archive backups are known as
what is type incremental. This means they will only include
files that have been modified since the last automated
backup was performed. These files will be
updated in the local backup directory
as well as forwarded to your remote backup location.
When it comes to your remote backup,
you have two choices for its configuration
if using the script provided with the PI Data Archive to perform the
remote backup. You can have the same backup
directory copied every time,
having it overwrite itself, thus only keeping the most recent
backup of your PI Data Archive.
Or you can create what is known as a repository of backups
where you keep backups from different points in time.
Here for instance, I have a backup
from March 1st, 2015 as well as a
backup from March 7th, 2015.
By creating a repository, you can see that I have different restore
points for my PI Data Archive.
For instance, if there was nothing wrong with my PI Data Archive at the time
of the most recent backup, I can use the most
recent backup to restore my PI Data Archive if necessary.
On the other hand, if I realize
I made a configuration change or deleted certain components
of my PI Data Archive that I shouldn't have, I can use an
older backup such as the one from March 1st, to restore
my PI Data Archive as long as it was taken before the
configuration change or deletion occurred.
This local and remote backup procedure via
automated tasks, is part of our recommended comprehensive
backup strategy for your PI Data Archive. However,
we recognize there may be times outside of this
regularly scheduled backup process where you'd like to take a
backup. For instance if I'm on the phone with a tech support
engineer performing troubleshooting or
testing steps, they may request we take a backup of the PI Data Archive right
then. In situations like this,
you can perform what is known as an on demand backup.
Here you can specify a subset
or all files in your PI Data Archive to be copied and
backed up to a particular location
that you can then use to restore your system on a new machine.
This on demand backup can be easily
performed through a plug-in to PI System Management Tools.
It is important to also note
that this on demand backup will not interfere with your regularly
scheduled automated backups.
Overall, a full backup strategy will include taking a
local backup of your PI Data Archive on a
dedicated disk drive. This backup should include
both your archive files as well as the
configuration information that is specific to your
PI Data Archive. Then your backup
strategy should include copying your local backup
directory to a remote
medium, ideally creating a repository of different backups from your
PI Data Archive over time. For more
information, please check out the following videos to
learn more about how to configure an automated backup test as well as
perform an on demand backup.