To install iFilters on Azure Cloud Services you need to perform the following steps:
%windir%\system32\inetsrv\appcmd set config -section:applicationPools -applicationPoolDefaults.processModel.idleTimeout:00:00:00"
ECHO Installing IFilters
start %RoleRoot%\approot\ExternalComponents\FilterPack64bit.exe /passive /norestart /quiet
Note: The Windows Search Service should be enabled on the Farm. You can do it manually or using the following PowerShell script:
Import-Module ServerManager
$check2 = Get-WindowsFeature Search-Service
If (!$check2.Installed) {
Add-WindowsFeature Search-Service
}
Enabling Search Services requires server restart. You can do it using suspend/start webrole using the Azure module or add "-restart" command to the above-mentioned powerShell script.
The solution was originally developed by Vicent Galiana and provided via the following blog post:
http://www.galysoft.es/post/2013/04/25/Enable-Ifilters-on-Sitecore-farm-on-Azure