Amazon EC2 linux web server maintenance & setup for magento website

Currently I have a new magento website hosted with amazon web services. We have been working with a development team putting the website together and building the product catalog for the last 2 months and are looking to launch the website "live." We have 18,000 products right now in the catalog and we plan to take this to over 100,000 products with a good amount of website traffic so we are looking for an experienced freelancer who can work with us to maintain the server with amazon and make the necessary changes when needed. Recently I was using the medium size server with amazon and I just changed this to the large server on the weekend because our website has been going "down" during CPU usage spikes. I believe this is happening when we are trying to mass upload products. Currently we are getting this error There has been an error processing your request SQLSTATE[HY000]: General error: 3 Error writing file '/tmp/MYTpdHkE' (Errcode: 28) Trace: #0 /var/www/lib/Varien/Db/Statement/Pdo/[login to view URL](110): Zend_Db_Statement_Pdo->_execute(Array) #1 /var/www/app/code/core/Zend/Db/[login to view URL](291): Varien_Db_Statement_Pdo_Mysql->_execute(Array) #2 /var/www/lib/Zend/Db/Adapter/[login to view URL](480): Zend_Db_Statement->execute(Array) #3 /var/www/lib/Zend/Db/Adapter/Pdo/[login to view URL](238): Zend_Db_Adapter_Abstract->query('SELECT `catalog...', Array) #4 /var/www/lib/Varien/Db/Adapter/Pdo/[login to view URL](428): Zend_Db_Adapter_Pdo_Abstract->query('SELECT `catalog...', Array) #5 /var/www/lib/Zend/Db/Adapter/[login to view URL](737): Varien_Db_Adapter_Pdo_Mysql->query(Object(Varien_Db_Select), Array) #6 /var/www/lib/Varien/Data/Tree/[login to view URL](183): Zend_Db_Adapter_Abstract->fetchAll(Object(Varien_Db_Select)) #7 /var/www/lib/Varien/Data/Tree/[login to view URL](192): Varien_Data_Tree_Dbp->load(Object(Varien_Data_Tree_Node), 0) #8 /var/www/app/code/core/Mage/Catalog/Model/Resource/[login to view URL](573): Varien_Data_Tree_Node->loadChildren(0) #9 /var/www/app/code/core/Mage/Catalog/Model/[login to view URL](818): Mage_Catalog_Model_Resource_Category->getCategories('2', 0, false, false, true) #10 /var/www/app/code/core/Mage/Catalog/Helper/[login to view URL](82): Mage_Catalog_Model_Category->getCategories('2', 0, false, false, true) #11 /var/www/app/design/frontend/xtremo/default/template/catalogsearch/[login to view URL](4): Mage_Catalog_Helper_Category->getStoreCategories() #12 /var/www/app/code/core/Mage/Core/Block/[login to view URL](241): include('/var/www/app/de...') #13 /var/www/app/code/core/Mage/Core/Block/[login to view URL](272): Mage_Core_Block_Template->fetchView('frontend/xtremo...') #14 /var/www/app/code/core/Mage/Core/Block/[login to view URL](286): Mage_Core_Block_Template->renderView() #15 /var/www/app/code/core/Mage/Core/Block/[login to view URL](919): Mage_Core_Block_Template->_toHtml() #16 /var/www/app/code/core/Mage/Core/Block/[login to view URL](637): Mage_Core_Block_Abstract->toHtml() #17 /var/www/app/code/core/Mage/Core/Block/[login to view URL](581): Mage_Core_Block_Abstract->_getChildHtml('topSearch', true) #18 /var/www/app/design/frontend/xtremo/default/template/page/html/[login to view URL](52): Mage_Core_Block_Abstract->getChildHtml('topSearch') #19 /var/www/app/code/core/Mage/Core/Block/[login to view URL](241): include('/var/www/app/de...') #20 /var/www/app/code/core/Mage/Core/Block/[login to view URL](272): Mage_Core_Block_Template->fetchView('frontend/xtremo...') #21 /var/www/app/code/core/Mage/Core/Block/[login to view URL](286): Mage_Core_Block_Template->renderView() #22 /var/www/app/code/core/Mage/Core/Block/[login to view URL](919): Mage_Core_Block_Template->_toHtml() and so forth... Our previous developer set everything up on one server and amazon has suggested that we switch this to split up the architecture and have the web components separate to the database and to use the load balancing. Send a bid to discuss further.