[solved] How to check memory usage?

[Johnm]

I had a quick question.

 

I just clicked the memory info button in umenu on my 5b6a build.

 

Memory Info

(from /usr/bin/free)

            total       used       free     shared    buffers     cached
Mem:       8298724    4837756    3460968          0      54112    4681864
-/+ buffers/cache:     101780    8196944
Swap:            0          0          0

 

I am interpreting this as over 50% of my 8gig is in use.

I am assuming that is from directory_caching.

 

It is pretty much the only add-on i am running besides apcupsd.

 

I got the extra memory for things like directory caching so that is fine.

 

I was just looking for a console command to get a more itemized report of what is resident in RAM.

 

 

EDIT:

 

Ok so i started a movie on my XBMC. and looked at the memory again.

 

Memory Info

(from /usr/bin/free)

            total       used       free     shared    buffers     cached
Mem:       8298724    8033804     264920          0      54300    7875892
-/+ buffers/cache:     103612    8195112
Swap:            0          0          0

 

this is just 15 min after the last reading. and it is still counting.

 

all my drives are asleep except the cache drive.

where the movie i am watching is resident.

 

EDIT 2 attached syslog.

the only thing that really caught my attention were the files that failed rsync because i had them opened.

the server has been on for less then 24 hours.

cache_dirs is set to only cache my movie directory.

syslog-memory.txt

[Johnm]

not sure if this will help.

 

it is a capture of "slabtop"

 

 

EDIT

 

Jun  1 18:07:00 Goliath cache_dirs: ==============================================
Jun  1 18:07:00 Goliath cache_dirs: command-args=-w -m 3 -M 10 -d 9999 -e *backup* -e *Backup* -a -noleaf
Jun  1 18:07:00 Goliath cache_dirs: vfs_cache_pressure=10
Jun  1 18:07:00 Goliath cache_dirs: max_seconds=10, min_seconds=3
Jun  1 18:07:00 Goliath cache_dirs: max_depth=9999
Jun  1 18:07:00 Goliath cache_dirs: command=find -noleaf
Jun  1 18:07:00 Goliath cache_dirs: version=1.6.5
Jun  1 18:07:00 Goliath cache_dirs: ---------- caching directories ---------------
Jun  1 18:07:00 Goliath cache_dirs: Media
Jun  1 18:07:00 Goliath cache_dirs: ----------------------------------------------
Jun  1 18:07:00 Goliath cache_dirs: cache_dirs process ID 3250 started, To terminate it, type: cache_dirs -q
Jun  1 19:06:01 Goliath crond[1220]: ignoring /var/spool/cron/crontabs/root- (non-existent user) 

 

max_depth=9999 looked deeper then I needed so i did a  "cache_dirs -q" and stopped it.

no change in RAM usage.

[Johnm]

well, now I'm confused.

 

I rebooted to see what happens. everything was back to normal.

 

I start watching a movie on my XBMC box (just a samba read, "top" shows it as smbd) and the memory starts getting chewed up again.

 

I pause the movie... the memory stops counting down.

 

i resume the movie... the memory starts getting eaten again.... and so on.

 

any ideas?

[kizer]

Just keep in mind Linux by nature will eat all the Ram it can. Is that bad? Not really it just means its not swaping drive space its using Ram which is a lot faster. Of course we are not using drives so its kind of a moot point, but I wouldn't worry about the Ram usage unless your machine starts having performance issues.

[Johnm]

thanks for the info...

[graywolf]

if you are worried about memory though, pay attention to the -/+ buffers/cache: line

 

As mentioned, *nix systems will use as much memory as it can for buffers and cache which is a good thing.

if your FREE memory on the -/+ buffers/cache: starts getting low, then you might start getting concerned.

 

In your examples, after starting XBMC, it used up 1832 memory, the rest of the increase was a little in buffers and a huge amount in cache (as would be expected)

 

[Johnm]

And this is why i am a windows admin.

 

Thanks guys.

[Joe L.]

And this is why i am a windows admin.

 

Thanks guys.

unless you have a HUGE amount of ram, it will almost all get used in the course of watching a movie, especially if you have ISO images that are multiple gig in size.

 

Unfortunately, unless you are backing up a chapter, the disk blocks read from earlier chapters in the movie are never read again until the next time you watch that movie again.  The disk buffer cache will use as much memory as it can, and will free it if needed.  At some point, additional memory will SLOW you down, as it is searched first for a requested block.  I think that is way more that we need to worry about, but it is theoretically possible once we get to where we have SSD drives and terabyte memory.

 

When a disk is accessed, if the block is not already in the buffer cache, once the buffer cache is full, the least-recently-used block of cache is re-used for the new access.

[Johnm]

I have 8 gigs of ram and I am seeing 7 gigs used at any given time.

 

I have actually been playing with virtualizing my unRAID the last few days.

 

I am now testing unraid,  my 2008 DC, a propriatary 2008 APP and WHS2011 clients on the same BOX.

 

I'll definitely assign less ram to unRAID if i go that route.