Archive for the ‘FOSS/GNU/Linux’ Category

gam_server ruining your IO throughput? Context switches hitting 8,000 a second?

Monday, November 5th, 2007

This hit me today.

The “gam_server” process. Set to identify when any file in the system is changed. A useful action that has benefits. But not when it does it 3-5 times per second and the sever is serving NFS and PostgreSQL!

To fix it, just ensure that somewhere in /etc/ (RedHat Base) or /etc/gamin/ (Debian Base) has a file called:

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When 73GB is not 73GB! Enter LVM

Sunday, October 7th, 2007

Thought I should write something tech for a change! ;-)

It is golden week here and all are away on break. So instead of forcing a staff member to come back, I thought I would take care of some stuff myself.

My problems started when a client who has a large advertising cluster, was running their main statistics database (for click fraud detection) on a Dell 1950 with only 1 SAS 15K drive.

I had suggested that this node, not being redundant like the tomcat servers be individually redundant, so DRAC card, redundant power and RAID.

Anyway, some new blades, Dell 1955′s arrived for the cluster and I thought, well, lets save the client some money, image the old 1950 DB server and load it onto a new 1955 server?

I thought this would be simple with Acronis.

No it wasn’t.

It turns out that a 3.5 Inch 73GB SAS drive is not the same size as a 2.5 Inch 73GB SAS drive. So I could not write my system image to the blades raid 1 array of 2 x 15K 73GB SAS drives.

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