Comments on: Linux’ kscand

By: Scott Alan Miller

Scott Alan Miller — Tue, 23 Mar 2010 13:48:10 +0000

In reply to Sumit. RHEL 4 and later, which use a 2.6 kernel, do not have kscand. On your system which is older than RHEL 4 (2.4 kernels end with RHEL 3) you will see both kscand and kswapd. RHEL is not versioned 2.4.x, that is a kernel version. Even if 2.4 was a RHEL version, it would still be older than 4.

By: Sumit

Sumit — Thu, 18 Mar 2010 07:42:00 +0000

Thank you for this nice article on kscand.

One thing you mentioned is that with RHEL 4 and later, kscand has been replaced with kswapd. However, on RHEL 2.4.21-47, I see both kscand and kswapd running.

By: Aditya

Aditya — Wed, 17 Mar 2010 14:22:15 +0000

It was a simple and thorough explanation of kscand process. We had to reduce the work_percent param in our RHEL 3 system for fixing node reboots after Oracle CRS upgrade. our case of because of high latency periods when kscand was running (It was running at 100%).

By: Scott Alan Miller

Scott Alan Miller — Mon, 09 Nov 2009 21:54:06 +0000

You are correct. You will not see kscand in the 2.6.9 or 2.6.18 (RHEL 4 and RHEL 5) systems. kscand was removed with the 2.6 kernel series. Similar functionality will be found split between kswapd and pdflush processes in these more modern systems.

By: Jia Rao

Jia Rao — Sun, 08 Nov 2009 04:57:52 +0000

It seems that kscand is removed from the newer linux kernel. I have several linux machines with 2.6.9 or 2.6.18 kernels. I can not find kscand running. The systems were left idle for several hours, but the active metric in meminfo does not change at all. I dont see a kscand_work_percent in /proc/sys/vm folder.