OpenVZ VM go frozen (Cannot allocate memory -- throttling) ?

[circut_breaker]

Welcome,

From 2 days i'm getting trouble with my VM working on Debian (5.0) - web-server.

First i will give some Symptoms.

1) Apache throw error: 503 (service unavailable)
2) Can't connect to VM via SSH ( ssh root@xxx
ssh_exchange_identification: Connection closed by remote host
)
3) Can't connect to VM via console in Proxmox
4) VM not hang, it's working... i can log in'to mysql, some apache process also running because i can visit some websites but not all.

I get only one option... i have reboot VM from Proxmox panel...
I can't see what's going on VM right now (display atop) because it's frozen and don't let me in.

In Proxmox on VM syslog i see that errors.

Mar 17 08:45:01 admin /usr/sbin/cron[727]: (CRON) error (can't fork)
Mar 17 08:45:11 admin postfix/master[678]: warning: master_spawn: fork: Cannot allocate memory -- throttling
Mar 17 08:45:11 admin postfix/master[678]: warning: master_spawn: fork: Cannot allocate memory -- throttling
Mar 17 08:46:01 admin /usr/sbin/cron[727]: (CRON) error (can't fork)
Mar 17 08:46:01 admin /usr/sbin/cron[727]: (CRON) error (can't fork)
Mar 17 08:46:11 admin postfix/master[678]: warning: master_spawn: fork: Cannot allocate memory -- throttling
Mar 17 08:46:11 admin postfix/master[678]: warning: master_spawn: fork: Cannot allocate memory -- throttling
Mar 17 08:47:01 admin /usr/sbin/cron[727]: (CRON) error (can't fork)
Mar 17 08:47:01 admin /usr/sbin/cron[727]: (CRON) error (can't fork)
Mar 17 08:47:11 admin postfix/master[678]: warning: master_spawn: fork: Cannot allocate memory -- throttling
Mar 17 08:47:11 admin postfix/master[678]: warning: master_spawn: fork: Cannot allocate memory -- throttling
Mar 17 08:48:01 admin /usr/sbin/cron[727]: (CRON) error (can't fork)
Mar 17 08:48:01 admin /usr/sbin/cron[727]: (CRON) error (can't fork)

Do you have any idea what can be wrong ?
Cpu say's 0 %
Memory of VM:
Memory/Swap (MB): 1442 / 6124


Regards

 

[dietmar]

You run out of memory.

 

[circut_breaker]

Hello,

Did you read my post ?

Memory usage VM 1400 MB / 6 GB

Proxmox server:

Physical Memory (5.22GB/1.51GB)
1.51GB

Still it's memory ?

BTW: 3 days ago i don't have any troubles.
That server runing in that configuration few months.

Any other idea ?

 

[dietmar]

Did you read my post ?

yes

fork: Cannot allocate memory

This indicates that you are out of memory.

 

[Nemesiz]

Add more ram memory to your VM (guest not host)

 

[circut_breaker]

Hi,

Thank You for reply.
I'm sorry if my previous message was rude but I'm little nervous... everyday i have remember to reboot VM.

First what i wan't to show... this is that VM... it's hanged... can't connect... "run out memory".



She use 30 % of allocated memory...
She have 4,5 GB real memory, 1,5 GB in swap.
She don't use it... so that's not memory problem...

Now i attach screenshot from ssh (Proxmox kvm server)



As you can see, no memory issues... 3,2 GB in cache.. no swap use...

And the free -m






Please help, i need better answer than put "reboot" in daily cron.... :/

 

[circut_breaker]

You had right.
That was memory apache (php5) issue.

I don't know why i don't show allocated memory.


Regards
Topic closed

 

[SamTzu]

We too had this problem in the beginning when we started to use OpenVZ. The concept of 'Swap' in OpenVZ world is a bit confusing since the Host harddrive's real file system is shared by all the VM's.
Just add more "swap" to your OpenVz VM's. Its shared memory anyway so it has very little adverse affects to the overall performance.