[Olpc-sysadmin] Machine status of OWL and proposed reconfiguration

Ed McNierney ed at laptop.org
Thu Jul 23 16:32:27 EDT 2009


Folks -

If anyone is interested in following up on the wiki work being done to  
accurately document our physical servers, virtual machines, DNS names,  
services, and the connections/relationships among them it would be  
immensely valuable to OLPC.  Even getting a firm answer to questions  
like "on what hardware is the www.laptop.org site hosted?" is not  
easy, and the wiki documentation is sometimes misleading or simply  
wrong.

I am trying to tackle a tiny piece of that puzzle by understanding OWL  
well enough to reconfigure it.  Here's the motivation.  Our large,  
production servers seem to be generally configured with RAID 5  
arrays.  This is not an especially good choice for database storage,  
especially with concurrent writes and reads, and I've learned that our  
wiki generates a surprising amount of database updates and deletions.   
Our wiki server itself (separate from squid and download links to  
crank) is having performance problems under load.  In addition, we  
have several MySQL instances floating about.  I would like to set up  
one, solid, well-designed and well-documented MySQL server machine,  
and migrate the wiki databases to it.

OWL is both a good physical candidate and lightly used.  It is  
configured as a RAID 5 array and I would like to reconfigure it (or at  
least part of it) as a RAID 10 array for database storage.  This is a  
much better performance choice, and even with a RAID 10 config the 8  
750 GB drives in that machine will give us 4 TB of storage.  Since  
that will blow away everything on the machine, I'd like to move  
carefully.

As far as I can tell, there are basically three things happening on  
OWL.  Please take a moment to review these and let me know if I'm  
missing or misunderstanding something.

1. There is a virtual machine called TEST and it appears to be the  
machine that serves http://test.laptop.org.  That site seems to serve  
only the page "It doesn't works!".  I cannot log in to this VM and  
cannot learn anything else about it.

2. There is a virtual machine called WWW2 that was alleged to be (see http://vig.laptop.org/wiki/index.php/Machine:www2) 
  the machine hosting www.laptop.org, but it's not.  I have suspended  
this VM and I can't figure out what it does.  I cannot log into it, as  
I don't know its IP address, DNS name, or whether I have any account  
on it at all.

3. There are 40 GB of backup files in the directory /home/sugarbackup/ 
backup/sunjammer and more are added daily.  There is no documentation  
whatsoever on the internal wiki or the VIG wiki about these files,  
this directory, or what is supposed to be happening here.

The documentation at http://laptop.org/internalwiki/index.php/Machine:owl 
  claims this machine hosts VMs named wwwseth and vm_test, but it  
doesn't.  The VM test seems to slightly resemble the machine vm_test  
documented at http://vig.laptop.org/wiki/index.php/Machine:vm_test but  
it's not the same.

PLEASE look over this information and - especially if you know  
anything about 1, 2, or 3 above  - let me know what you know.  It  
seems to be that #1 and #2 are indeed unimportant and can just go  
away.  I'm not sure about #3, but no one seems to have written  
anything down about it so I can't tell.

If you have thoughts on the topic of creating an optimized MySQL  
server machine (see http://laptop.org/internalwiki/index.php/ 
Machine:owl for the hardware specs) or on the proposal to create a  
single MySQL server to serve our various needs, I would appreciate  
hearing them.  Thanks!

	- Ed


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