Extra ram not recognised

[avalon60]

I have a supermicro X9SCM(-F) motherboard with x2 8Gb Kingston ECC 1600Mhz Value select ram to give 16Gb. These ram sticks are in slots DIMM2A and DIMM2B, blue slots

I have just bought x2 Kingston KVR16R11S8/4I RAM 4 GB 1600 MHz DDR3 ECC Registered CL11 DIMM 240-Pin, Intel Certified ram stick and put them in DIMM1A and DIMM1B.
I booted up my FreeNAS and the extra x2 4Gb ram is not recognised by FreeNAS.
Any ideas as why this is, because in a desktop PC I'm pretty sure it would be recognised.

Thanks

 

[Johnnie Black]

ECC Registered

X9SCM is unbuffered ECC only.

 

[avalon60]

Aah right, I didn't realise that.
Will this be ok:

Kingston Kth-pl316es/4g 4gb Pc3-12800e ECC Unbuffered

It's 1600Mhz , the same speed I have
Thanks

 

[joeschmuck]

When it comes to recommending RAM, the safest advice is always to refer to the vendor QVL list for your motherboard. If you want to take a chance and use a different brand, speed, etc... than on that list then you are taking a chance it will not work or may not be reliable. Many of us check out that list and then we buy something that may use the same chipset type/brand. Heck, on one system I purchased 8GB sticks where the QVL only listed 4GB sticks, but same vendor and brand and speed. RAM prices were high for ECC RAM but I took the risk and it worked great.

Remember to run MemTest86 on your RAM, ensure you have a solid base before running FreeNAS and risking your data. Run the CPU burn-in test of your choice as well to ensure you know all is good.

 

[avalon60]

Thanks for the advice, and well taken.

My FreeNAS box has ran happily for 6 years on its' present 16Gb of ram, and recently I've noticed that it has been near enough maxing out. But that's only because I have looked at that time. I just thought it might be a bit better with another 8gb, but again maybe not required

 

[joeschmuck]

Thanks for the advice, and well taken.

My FreeNAS box has ran happily for 6 years on its' present 16Gb of ram, and recently I've noticed that it has been near enough maxing out. But that's only because I have looked at that time. I just thought it might be a bit better with another 8gb, but again maybe not required

First of all, reading RAM usage is tricky when it comes to FreeNAS and Linux in general, mainly because RAM does not look like it gets freed up when not in use. For your concern I point you to SWAP Space.

So what you can do to figure out if you need more physical RAM, check the SWAP file size. If you are using the SWAP file then you have run out of RAM. But let's temper that statement a little bit with it does depend on how much SWAP space you are using. If your SWAP usage is less than 500KB (I pulled that number out of my butt and it's just a value where I would personally be concerned), I wouldn't worry about it much, but if your SWAP usage in MB range and often, then you have a hardware limitation problem and should either add more RAM or possibly look into any jails/plugins you have to remove/disable what you can.

If you have 500KB or less of SWAP usage then adding RAM would basically make cached files (files accessed frequently) available quicker. There is more to it than that to be honest with you but making your system overall faster, generally it will not but it does depend on your use case. I'm sure there is a lot you could read about RAM shortages with FreeNAS, look up "SWAP space RAM FreeNAS" on the internet or something like that and I'm sure you will find something, it could take a while to filter through some garbage.

I will always promote adding more RAM if it's available but in your case since your system has been working for such a long time without complaint, I'm not sure I'd add any more without good reason. I'd save the money for next set of hard drives you will need to buy.

Also, I run my FreeNAS on ESXi 7.0 with 16GB RAM and it runs great so you are not the only person running 16GB RAM. I'm only running Plex in a jail and I do not use any SWAP space so maybe you really don't need the extra RAM.

Good luck.

 

[avalon60]

Thanks, and when I do 'top' in a FreeNAS shell I see the swap is listed as: SWAP: 8192M 8192M Free, so the swap file is not being used in this case.
On the dasboard gui for Memory I have 0.4Gib free and ZFS cache is using 13.1Gib, while service are using just 2.3GiB

Would extra memory make any difference to the ZFS cache, ie , would it stay at 13.1 Gib, or go up accordingly, or am I barking up the wrong tree.

 

[joeschmuck]

SWAP: 8192M 8192M Free, so the swap file is not being used in this case.

Correct.

On the dasboard gui for Memory I have 0.4Gib free and ZFS cache is using 13.1Gib, while service are using just 2.3GiB

Would extra memory make any difference to the ZFS cache, ie , would it stay at 13.1 Gib, or go up accordingly, or am I barking up the wrong tree.

To answer your question would mean I'd need to know how you use FreeNAS. If you are hosting files that are frequently accessed (the same files such as a busy database) then yes a larger cache could help. If you are hosting video files (movies) or music files where you are randomly accessing data then no a larger cache won't really help. Also understand that FreeBSD (what FreeNAS is built on) will use as much RAM as it can get so it looks like it's eating up all the RAM, as opposed to Windows where it only consumes RAM it needs and leaves the rest free.

The key takeaway here is your SWAP space is not being used so you have not run out of RAM. If you want to add more RAM, no one will tell you not to but when you ask if you need more RAM, then I'd say the answer is no. There are a lot of postings on this topic, you just need to search the internet for it and do some leg work, you will find it.

 

[avalon60]

My FreeNAS machine just hosts video files which are streamed to my TV just now and again. It also has pictures and video files sent to it / recorded to disk from my CCTV system 24/7 but on motion detection, rather than continuous.

Overall I'd say extra ram wouldn't make much of a difference , so I'll do as you say and save my money. Looking at the dashboard gui now, the memory section shows: Free 1.8GiB, ZFS Cache 11.6GiB and Services 2.4Gib

I take your point about FreeNAS using as much ram as it can get, so if there was more it would use it.
Just out of interest my linux desktop has 16Gb of ram and 8Gb of that is used as cache.
Thanks

 

[joeschmuck]

No problem, just trying to help someone out, that's what we do here. Well sometimes we make someone miserable but those are just the perks