Site Error - Zope and other services crashing - Zenoss 5.0.2

The last few days when I've come in, I've found Zenoss in an unresponsive state. The main page dumps the below error. The Control Center showed several services in a down state, including CentralQuery, Zope, redis, collecttoredis, and a few others that I do not recall at the moment. CC was all-in-all relatively unresponsive, including Logs. Running 'serviced service restart Zenoss.core' hung. I was forced to restart serviced to get things back up and running.

This install has about 300 devices and otherwise is working pretty well. Disk space was not the issue.

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Site Error

An error was encountered while publishing this resource.

Sorry, a site error occurred.
Traceback (innermost last):

Module ZPublisher.Publish, line 237, in publish_module_standard
Module ZPublisher.Publish, line 165, in publish
Module Zope2.App.startup, line 230, in __call__
Module Products.ZenUI3.browser, line 103, in __call__
Module Products.ZenWidgets.FileGzipper, line 82, in __call__
Module Products.Five.browser.pagetemplatefile, line 59, in __call__
Module zope.pagetemplate.pagetemplate, line 113, in pt_render
Module zope.tal.talinterpreter, line 271, in __call__
Module zope.tal.talinterpreter, line 343, in interpret
Module zope.tal.talinterpreter, line 858, in do_defineMacro
Module zope.tal.talinterpreter, line 343, in interpret
Module zope.tal.talinterpreter, line 852, in do_condition
Module zope.tal.talinterpreter, line 343, in interpret
Module zope.tal.talinterpreter, line 533, in do_optTag_tal
Module zope.tal.talinterpreter, line 518, in do_optTag
Module zope.tal.talinterpreter, line 513, in no_tag
Module zope.tal.talinterpreter, line 343, in interpret
Module zope.tal.talinterpreter, line 742, in do_insertStructure_tal
Module Products.PageTemplates.Expressions, line 218, in evaluateStructure
Module zope.tales.tales, line 696, in evaluate
URL: /opt/zenoss/Products/ZenUI3/browser/error_message.pt
Line 71, Column 0
Expression:
Names:
{'args': (),
'container': InternalError(3, "Error writing file '/var/tmp/#sql162_90_17ab4.frm' (Errcode: 28)"),
'context': InternalError(3, "Error writing file '/var/tmp/#sql162_90_17ab4.frm' (Errcode: 28)"),
'default':

Troubleshooting Suggestions

The URL may be incorrect.
The parameters passed to this resource may be incorrect.
A resource that this resource relies on may be encountering an error.
For more detailed information about the error, please refer to the error log.

If the error persists please contact the site maintainer. Thank you for your patience.
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Any thoughts