Geoscada - reduce system memory

[Valentino]

I have a question about GeoSCADA.

The costumer has 10 years (2011-2021) of historical data online and wants to archive 7 (2011-2018).

Can I create multiple archives?

archive 1 (2011)

archive 2 (2012)

archive 3 (2013)

archive 4 (2014)

Etc...

How can I do it?

In case I can only create an archive therefore of 7 years.

can I divide them and create 7 archives for a year manually?

I know that it cannot be archived for more than 6 months. For what reason?

However this data must remain accessible to trends and queries. For example by mounting the corresponding archive.

This is because I have to reduce the memory of a system that has 10 years online and no longer has available memory.

(the system has 90GB and occupies about 9GB each year)

is there another solution?

what is the ideal solution without implementing a server in stendby?

[AdamWoodland]

Can you confirm what memory you are referring to? Virtual memory/RAM or hard disk usage? You mention 9GB a year, that seems like a lot of virtual memory being used by the historic index so could instead be disk space you refer to, but then 9GB is pretty low in terms of disk space usage per year.

Either way, I believe the cheapest, quickest and best result for the users of the system would be to buy and install more RAM and/or disk space rather than messing about with archives or other possible answers. RAM and disks are pretty cheap these days, unless you've got some special setup.

Archives could probably do what you want (along with trimming the historic storage period after the archive) but I generally avoid archives due to personal preference and haven't used them in 15 years. Usually the media used is slower so user experience is impacted. Plus the effort used to swap media around as necessary to access the relevant data period.

Another option could be using a dedicated historian, but then you're looking at another machine and potentially just shifting the same problems elsewhere.

[BevanWeiss · Accepted solution]

Do you mean 'memory' (i.e. RAM)?

Or do you mean disk space?

Based on this.. 

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(the system has 90GB and occupies about 9GB each year)

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I suspect you mean disk space.

Archives are a possible option, but they are quite difficult to use.  You need to create new volumes with unique names for them to work correctly.  I've never really used them, since disk space is so cheap (and in virtual environments easy to provision).

Is there a reason that you can't just increase the disk space available to store historic data?

If you install a new hard drive (or provision a new virtual drive) then you can move the existing historic data to this drive just by changing the directory to use in the Server Settings.  Of course doing this is slightly risky, because that sounds like an awful lot of historical data to be moving, and it will result in the system performance really suffering at that time.  If you have hot standby servers, you might want to investigate doing this on the standby server, potentially even shutting down the standby, and changing the path, then just having it resynchronise everything to the new volume.  It would be a long time to synchronise, and would need risk mitigations to ensure availability during that time.. but it's possible.

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I know that it cannot be archived for more than 6 months. For what reason?

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What do you mean by this?  I'm unaware of any '6 month' limitation in regards to Geo SCADA Expert historical data at all.  So I'm unsure how you 'know that it cannot be archived for more than 6 months'...

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what is the ideal solution without implementing a server in stendby?

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Also unsure how standby server relates to historical data here.  Obviously a standby server provides higher availability in the event of a failure for a single server.  And it certainly makes certain activities more reasonable, like deploying a new server with a larger hard drive... since you could then have it as standby on the new hardware, synchronise everything up and then fail across to it whilst you take the other server out of service (or upgrade its hardware).

You could do a similar process without the standby server however.  Depending on your hardware, you may be able to hot-add additional hard drives, you could then repoint your Geo SCADA Expert locations to use the new hard-drive as the historical storage location.  This is where you may have a challenge, since moving all that data will make the server performance terrible until it is all migrated.  I'm unsure whether Geo SCADA Expert will do this nicely, I'd definitely test it on an offline system first.  My suspicion is that it won't be very nice.. and database lock % will skyrocket, response latency will go super high, connected ViewX applications may freeze up or crash, and outstations won't be polled at the configured frequencies.  It's why I'd recommend doing this on the standby server...

[Valentino]

Thanks for your kind replies. I am referring to the memory used on the hard disk which is now full.
I understand that the most suitable solution is to act on the hardware instead of on the software.

@BevanWeiss  @AdamWoodland 

[Ambartsum]

9Gb Data per year is reasonable I guess, so yes you dont need to touch the software.

If i understood well, you are running with 90Gb of Hard Drive Disk memory wich is very low nowadays ( Phones have more memory than that). Buying an 500Gb HDD is very cheap and it will be 50 year storage with your actual consumption rate.

Your best option is to upgrade the Drive memory but the difficult part is to transfer files from old drive to the new one. There are risks that you need to take into account.

One of the best solution would be to do that while your process/system is offline. Is it possible to turn it off ?

[Valentino]

@Ambartsum 

Unfortunately I don't think it's possible to turn it off. The customer should arrange to have a day off duty.
To transfer data from the old hard drive to the new one, do I have to use a software to clone the hard drive? if so, it can also be done with the server logged on

[Ambartsum]

I dont have a good knowledge of GeoSCADA system so I cant help you that much. I dont think you need to clone the whole disk but just the data you need ? Also maybe there is a precise process to follow if you want to copy datas while your system is online... Better wait @BevanWeiss or @AdamWoodland answer, they might have already done what you are looking for. 

[BevanWeiss]

I already discussed this in my response.

You can do this online.  You just go to the Server Configuration and change the Location specified for the Historic Data (and Files most likely also).  This will perform a move of the files... but it will likely have a very bad performance impact.  Hence why I would recommend doing this only on the Standby server.

This of course assumes that you can get the computer to have additional storage 'online' also.  Such as if the server is virtualised, and you are just provisioning extra space (or another volume), or if the server supports hot-add of harddrives (which most SATA interfaces support.. but it does depend on motherboard).  If you need to turn the physical server off to install the harddrive, then of course you're going to lose the availability of that server.  If you don't have a standby server, then you will lose availability of your SCADA system.