I have a CentOS 6.5 x86_64 system that's been running problem-free for quite a while.
Recently, it's locked-up hard several times. It's a headless server, but I do have IP KVM. However, when it's locked up, all I can see are a few lines of kernel stack trace. No hints to the problem in the system logs. I even enabled remote logging of syslog, hoping to catch the errors that way. No luck.
I ran memtest86+ for about 36 errors, no problems.
I've tried to strip away just about all running services. It's just a home file server. I haven't had a crash in a while, but I also haven't had it running very long.
But even while it's up, I have severe input lag in the shell. I'll type a few characters, and two to 10 or so seconds pass before anything echoes to the screen.
I've checked top, practically zero CPU load.
It's not swapping - 16 GB of RAM, 0 swap used. Most memory heavy process is java (for CrashPlan backups).
iostat shows 0% disk utilization.
Anyone seen anything like this? Where else can I check to try to determine the source of this lag (which I suspect might be related to the recent crashes)?
Thanks, Matt