Archive for June, 2005

Finding busy disks with iostat

The iostat(1M) utility provides several I/O statistics, which can be useful for analyzing I/O workloads and troubleshooting performance problems. When reviewing I/O problems, I usually start by reviewing the number of reads and writes to a device, which are available in iostat’s “r/s” and “w/s” columns: $ iostat -zxnM 5 extended device statistics r/s w/s […]

mpstat’s wi (wait on I/O) statistic

I have used mpstat over the years to check system performance metrics, and always wanted to know what went on behind the scenes. With the recent release of opensolaris, I can finally find out how mpstat gathers the statistics it displays (it uses the kstat interfaces). One statistic that has always been confusing is “wt.” […]

Veritas hostid debugging

I was approached by a colleague last week to investigate a problem with Veritas Volume Manager simultaneously importing a disk group on two different nodes (this is ok if your using CVM, but we weren’t). As you can imagine, this is a BAD thing, and can lead to chaos and data corruption (depending on what […]

Printing PICL information

The Solaris operating system comes with the picld daemon, which allows hardware specific data to be presented in a general way. When clients read data from a PICL implementation, they can be ensured that “temperature” (or any counter value for that matter) means the same thing across different hardware implementations. To print the PICL tree, […]

Making Solaris DHCP server IP addresses usable

While working through a few issues with our x86 jumpstart setup, I saw the following error messages when one of the clients was attempting to PXE boot: 429f62d0: Datagram received on network device: ge0(limited broadcast) 429f62d0: (01000D609C8888,1.2.3.4) currently marked as unusable. To make the IP address usable again, I used the Solaris pntadm utility: $ […]