I’m not familiar with how swap works, but by looking at the system information upon login, it appears my memory usage is far lower than what Digital Ocean shows. Is this because of the usage of swap? I’m trying to gauge how this 1GB instance will hold up with my current and future users.
It’s really hard to make any sense of “free memory” because it’s a flexible resource which gets used for different purposes.
That said, you are a bit short - but so am I, in the same situation (78 active users in 7 days and 114 active in 30 days):
total used free shared buff/cache available
Mem: 985M 780M 63M 23M 141M 53M
Swap: 2.0G 1.1G 964M
I’ve written elsewhere and recently, perhaps follow up these other comments:
Also
You have two things to worry about, day to day: the performance of the forum, and the likelihood of a crash because you actually ran out of memory (meaning, your swap all got used and wasn’t enough). If you can monitor swap activity, using a provider’s dashboard or using ‘vmstat 5 5’ on the command line, I’d say do that. If you can monitor your forum’s responsiveness, maybe do that too.
And then month to month you find yourself performing an update, and that will need more memory than the day-to-day forum operation. If you are swapping heavily during an update, the update will take longer than usual. If your swap gets exhausted, you could have a crash and that could be really bad.
Your swap is already half-used - if you have the disk space to double it, do that.
Great information and link at the bottom of your post!
In my instance, I see I have 74MB available, but I do see 165MB is being used for buffer/cache. Which, if I understand correctly, can be used by the system. This is part of disk caching… In your link, it seemed like the idea was “available” is everything available to you including buff/cache. So I’m still confused there.
However, I see I am using 723MB out of 968MB total, which tells me I still have 245MB to spare…
Do I follow?
If so, then the last screenshot I shared with “System information” showing 83% memory usage would appear correct, and mean I’m not really close to any danger…
If you want to write down on paper the answer Ed gave you, the ability of memorizing only one word is enough. You just have to write it down and look up at your screen to memorize the next word, and so on. It will even work if you can only memorize one single character. But you would save time by being able to memorize the whole post at once. You wouldn’t have to waste time looking up a lot of times to do things in small batches.
If I’m not mistaken, when a program has access to more available memory, it will use more and it will improve its performance. It isn’t a strict fixed value usage. Also, RAM is quite faster than a disk: Using RAM rather than swap is better.
I don’t know what makes you say that. Did you maybe look at the wrong line? Or maybe I’m misinterpreting the “far”. It might be the small tick lower at the end of the graph?
Because any in-use memory can be swapped out, it can be freed if needed. So measuring what’s in use doesn’t tell you how much could be in use, if there were more RAM available, or if there were memory pressure. It’s like trying to measure how much air is in a ballon by seeing how large it is. Well, it isn’t, but I’m sure there’s an analogy somewhere. Maybe it’s like measuring the success of a retail outfit by seeing how much cash is in the till.
It’s important to note that there’s two quite different senses of “not enough memory” - one is “my forum is slow” and another is “my forum crashed.”
For a small and low-traffic forum, 1G still seems to be enough, although each new version of the software will potentially make it more marginal.
