VPS freezes everyday no SSH access.

June 27, 2016 271 views
LEMP WordPress Ubuntu 16.04

I have a Ubuntu 16.04 VPS running LEMP (512MB Droplet). This server hosted 3 WordPress sites. Which has 500 daily traffics to 2 sites, other one doesn't have any traffic. All the time RAM usage bellow 300MB and CPU usage also bellow 50% (according to the NewRelic Server monitor)

Problem is everyday after the backup (wordpress backup plugin) run or while running all the sites goes offline and can't connect via SSH (guess server goes offline). All the 3 sites backup are not run at the same time. But digital ocean control panel display that server Up (a green icon in droplet). But if I run CamAV scan, (it use higher memory, CPU than other) there's no such a issue.

To fix this issue every time I have to use Digital Ocean "Power Cycle" option. After that again sites are Up and SSH working.

If I reboot the VPS daily (before the site backup) then there's no such a issue. After that plugin started and completed backup no such a issue.

How do I identify the real reason for this matter? If this is a PHP issue, does it case such unable to connect SSH issue?

*This is NewRelic last 24 hours memory usage (including the this issue occurred time period) *
Click here View Memory Usage Screenshot

Thanks in Advance.

1 Answer

I would strongly recommend reviewing your log files. Generally for multiple services to become unresponsive indicates something like a kernel panic or exhaustion of available memory. If the memory use spiked quickly the server may have become unresponsive before the agent reported the change to NewRelic. You can try adding a swap file on your droplet. If the issue is memory related this should resolve it but step one should be to review the logs in /var/log/ around the time the droplet became unresponsive.

by Justin Ellingwood
Swap space can be used as an "overflow" area for your system when you run out of RAM. The operating system can store data that would normally be kept in RAM on the hard drive in a specially formatted file. In this guide, we'll demonstrate how to create and use one of these files in Ubuntu 14.04.
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