Running sync on ext4 filesystem causes soft lockups on Red Hat Enterprise Linux 5.4

Solution Unverified - Updated -


  • typing 'sync' causes ext4 writes to effectively stall.

  • ext4 filesystem write performance drops to 1/100th or less if there are dirty pages and you simply type 'sync'.  'top' shows kjournald2 and sync both taking 100% CPU.


  • Red Hat Enterprise Linux 5.4

Subscriber exclusive content

A Red Hat subscription provides unlimited access to our knowledgebase, tools, and much more.

Current Customers and Partners

Log in for full access

Log In

New to Red Hat?

Learn more about Red Hat subscriptions

Using a Red Hat product through a public cloud?

How to access this content