[Users] vzubc, memory, and buffers

[Keith Keller]

Hi again users,

I wanted to ask a quick question about the vzubc utility and buffers
inside a container.  I have a container which has a lot of disk buffers
currently being stored in memory:


$ free
             total       used       free     shared    buffers     cached
Mem:       4194304    4116528      77776          0          0    3591588
-/+ buffers/cache:     524940    3669364
Swap:       524288          0     524288

This is IME a perfectly normal and acceptable situation (and the
container is behaving normally).

However, vzubc thinks that this is a warning situation:

# vzubc -q  -r 
----------------------------------------------------------------
CT 1018      | HELD Bar% Lim%| MAXH Bar% Lim%| BAR | LIM |+FAIL
-------------+---------------+---------------+-----+-----+------
    physpages|3.93G   -   98%|   4G   -  100%|   - |   4G|    - 
----------------------------------------------------------------

What do people normally do in this situation?  Would you simply ignore
warnings on physpages, or actively check the free buffers situation in
that CT?

In what might be a related question, I saw that vzcfgvalidate reports a
somewhat strange error in this CT:

# vzcfgvalidate 1018.conf 
Warning: swappages.lim should be <= 0 (currently, 131072)
# grep SWAP 1018.conf 
SWAPPAGES="0:512M"

But isn't swappages.lim set to 512M here?  And why should it be set to
less than or equal to 0?  And why does vzcfgvalidate think it's some
number not 0 or 512M?

If it's helpful, here's my list of packages (this is a CentOS 6 box):

vzctl.x86_64                    3.3-1 @openvz-utils       
vzctl-lib.x86_64                3.3-1 @openvz-utils       
vzkernel.x86_64                 2.6.32-042stab055.10 @openvz-kernel-rhel6
vzkernel-firmware.noarch        2.6.32-042stab055.10 @openvz-kernel-rhel6
vzquota.x86_64                  3.0.12-1 @openvz-utils       

And kernel (yes, I know it is not the latest):

# uname -a
Linux xxxxxxxxxx 2.6.32-042stab055.10 #1 SMP Thu May 10 15:38:32 MSD 2012 x86_64 x86_64 x86_64 GNU/Linux

Thanks for any advice you have!


--keith


-- 
kkeller at wombat.san-francisco.ca.us