Bug #1854
closed
  
Bugs while using encrypted HAMMER root fs
 
        
        Added by matthias about 15 years ago.
        Updated over 3 years ago.
        
  
  
  
  Description
  
  Moin,
	I installed a recent master (2.7.3.1095.g4cdde1) on my old IBM Thinkpad T42 and I installed the system on an encrypted HAMMER root volume.
While installing packages and using X I made some observations:
	
	- After a crash, the "loader" in the initial ramdisk is no longer able to load the real init.  It displays all HAMMER related messages about an unclean file system and stops right after "recovery complete".  I can move the cursor and panic the system, but nothing else happens. Rebooting the live CD and mounting the partition fixes the problem.
 
	
	
	- The systems tends to freeze regularly during heavy disk activity.  No crash dump, no messages, just everything stops working.  Not sure if thats related to the crypto stuff ...
 
	
	Anybody an idea whats going on?
	Cheers
	Matthias
   
 
 
  
  
    
    
    
    
	Moin,
	I installed a recent master (2.7.3.1095.g4cdde1) on my old IBM Thinkpad
T42 and I installed the system on an encrypted HAMMER root volume.
While installing packages and using X I made some observations:
	- After a crash, the "loader" in the initial ramdisk is no longer able
to load the real init.  It displays all HAMMER related messages about
an unclean file system and stops right after "recovery complete".  I
can move the cursor and panic the system, but nothing else happens.
Rebooting the live CD and mounting the partition fixes the problem.
	I can reproduce it.  Every time I run "hammer cleanup" the system
freezes.
	Cheers
	Matthias
 
     
   
  
  
    
    
    
    :
:* Matthias Schmidt wrote:
:> Moin,
:> 
:> I installed a recent master (2.7.3.1095.g4cdde1) on my old IBM Thinkpad
:> T42 and I installed the system on an encrypted HAMMER root volume.
:> While installing packages and using X I made some observations:
:> 
:> - After a crash, the "loader" in the initial ramdisk is no longer able
:>   to load the real init.  It displays all HAMMER related messages about
:>   an unclean file system and stops right after "recovery complete".  I
:>   can move the cursor and panic the system, but nothing else happens.
:>   Rebooting the live CD and mounting the partition fixes the problem.
:
:I can reproduce it.  Every time I run "hammer cleanup" the system
:freezes.
:
:Cheers
:
:    Matthias
	How much memory does this system have?  The problem is almost
    certainly buffer cache / memory-exhaustion.  The crypto layer
    uses memory heavily.  We need a kernel panic / kernel core
    when it gets stuck to verify that is the issue.  Swap cannot
    be encrypted if you want the kernel core to have a chance of
    succeeding in this situation.
	Both hammer cleanup and crypto are heavy kernel memory users.
	-Matt
                    Matthew Dillon 
                    <dillon@backplane.com>
 
     
   
  
  
    
    
    
    Moin,
	
	How much memory does this system have?  The problem is almost
certainly buffer cache / memory-exhaustion.  The crypto layer
uses memory heavily.  We need a kernel panic / kernel core
when it gets stuck to verify that is the issue.  Swap cannot
be encrypted if you want the kernel core to have a chance of
succeeding in this situation.
	Both hammer cleanup and crypto are heavy kernel memory users.
	1GB RAM.  The swap partition is not encrypted, only the HAMMER root fs.
The machine froze various times in the last days, but I didn't get a
dump ... any ideas?
	Do you have any idea why the system cannot load the real init process
when the HAMMER fs is unclean?
	Cheers
	Matthias
 
     
   
  
  
    
    
    
    
	How much memory does this system have?  The problem is almost
certainly buffer cache / memory-exhaustion.  The crypto layer
uses memory heavily.  We need a kernel panic / kernel core
when it gets stuck to verify that is the issue.  Swap cannot
be encrypted if you want the kernel core to have a chance of
succeeding in this situation.
	Both hammer cleanup and crypto are heavy kernel memory users.
	I was able to crash the system but I didn't get a crash dump again.  I
started dozens of applications in X (including FF and soffice) and ran
hammer reblock while on syscons.  The last message I saw before the
system freezed was:
	td 0xc04a24c0 (ithread 69) unexpectedly rescheduled
	Cheers  
	Matthias
 
     
   
  
  
    
    
    
    Maybe you could write a script that continuously (every 500ms?) refreshes a vmstat 
-m output of dm and dm_crypt malloc tags and then run hammer reblock in the 
background?
 
     
   
  
  
  
  
    
    
    
    
       - Description updated (diff)
 
       - Assignee deleted (
0) 
    
    
     
   
  
  
    
    
    
    
       - Description updated (diff)
 
    
    
     
   
  
  
    
    
    
    
       - Status changed from New to Closed
 
       - Assignee set to tuxillo
 
    
    Assuming the mentioned commit fixes the problem.
 
     
   
  
 
  
  
 
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