Archive for 'Linux performance'

Getting an accurate view of process memory usage on Linux hosts

Having debugged a number of memory-related issues on Linux, one thing I’ve always wanted was a tool to display proportional memory usage. Specifically, I wanted to be able to see how much memory was unique to a process, and have an equal portion of shared memory (libraries, SMS, etc.) added to this value. My wish […]

Why isn’t Oracle using huge pages on my Redhat Linux server?

I am currently working on upgrading a number of Oracle RAC nodes from RHEL4 to RHEL5. After I upgraded the first node in the cluster, my DBA contacted me because the RHEL5 node was extremely sluggish. When I looked at top, I saw that a number of kswapd processes were consuming CPU: $ top top […]

Tuning network and vm settings on CentOS Linux servers with ktune

While poking around the CentOS package repository, I came across the ktune package. Ktune comes with a set of kernel tunables that are useful for network and disk intensive workloads, and provides the ktune service to apply these settings during system startup. Ktune includes settings for TCP/IP buffers, setting the deadline scheduler as the default […]

Monitoring Linux server performance with procallator

I manage a fair number of Linux hosts, and like to keep tabs on how my systems are performing. One way I accomplish this is with procallator, which is a Perl script that collects performance data that can be graphed by orca. The graphs that orca produces are great awesome for trening server performance over […]

Speeding up Oracle disk I/O on RHEL4 systems

While poking around the web last wek, I came across a good paper from Redhat that describes how to utilize asynchronous and direct I/O with Oracle. I have been using the Oracle filesystemio_options=”SetAll” initialization parameter on a few RHEL 4 database servers to efficiently use memory, and had no idea idea that it provided the […]