4.0 ice cream sandwich - How can I get rid of the low disk space notification?

The low disk space notification frequently comes up. I can't get rid of it; the clear button doesn't clear it, and neither does tapping it. It's just taking up space. How can I get rid of it?

I've got 20 MB of free space on my phone, which isn't a lot, but it's sufficient. I already know how much space is available, so a constant reminder serves no purpose, as there's nothing I'm willing to delete to free up space.

This is a Google/HTC Nexus One running Android 4.0. (Quite an old phone to be running ICS, but it was like that when I aquired it secondhand.)

Edits in response to the comments and answers:

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  I've already moved all possible apps to the SD card, and even a few that weren't supposed to be moved there. Unfortunately, Android insists on keeping some stuff on the phone, even when the apps are moved off. As a Linux user, I can't understand this. By a combination of choosing the $PATH well and manipulating mount points and symlinks appropriately, I can't see why it should make any difference to the system where the app is installed.

  
  


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  I've already cleared the cache. There's not much there, since I've been aggressive in my cache management. I've even cleared out several apps' data.

  
  


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  I haven't yet gotten around to moving my data to the SD card, as I asked about here. I think it'll only amount to a few MB of savings, though.

  
  

Answer

It is enormously annoying, isn't it? There's no way to suppress it on an unmodified system that I know of, but you can at least free up more internal disk space by emptying system and app caches using an app like SD Maid or by going into the application management section (Settings->Applications->Manage Applications->All, then click on an app name) and manually clearing out app data for hogs like Google Maps and the like using the Clear cache button (note: don't clear the app data! just the cache).