Excessive disk activity by kernel_task?

Question

I have a weird problem that I think only started with the upgrade to 10.9.2.  I have a mid-2010 MBP, 15", 8GB RAM.  I have a Seagate hybrid disk in it.  It didn't used to do this, but now, after a few minutes, it becomes sluggish.  Looking at Activity Monitor, it's doing about 300 writes/second, and about 3MB/second.  Eyeballing the process list, it looks to me like it's kernel_task itself that's doing the writes.  There isn't memory pressure, so I have no idea why it would be writing so furiously.
Has anyone seen this before, or do they have a suggestion for how to dianose what would be making the kernel write to disk so furiously?
Thanks!

Answer 1

it becomes sluggish
When you have the problem, note the exact time: hour, minute, second.
These instructions must be carried out as an administrator. If you have only one user account, you are the administrator.
Launch the Console application in any of the following ways:
☞ Enter the first few letters of its name into a Spotlight search. Select it in the results (it should be at the top.)
☞ In the Finder, select Go ▹ Utilities from the menu bar, or press the key combination shift-command-U. The application is in the folder that opens.
☞ Open LaunchPad. Click Utilities, then Console in the icon grid.
Make sure the title of the Console window is All Messages. If it isn't, select All Messages from the SYSTEM LOG QUERIES menu on the left. If you don't see that menu, select
View ▹ Show Log List
from the menu bar.
Each message in the log begins with the date and time when it was entered. Scroll back to the time you noted above. Select the messages entered from then until the end of the episode, or until they start to repeat, whichever comes first. Copy the messages to the Clipboard by pressing the key combination command-C. Paste into a reply to this message by pressing command-V.
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