Huge Analysis Services log file: msmdsrv.log
You can't recycle the SSAS log in a similar manner to SQL Server. You need to do this manually by building a script and then scheduling it to run either inside of SQL Agent or Windows Task Scheduler. 

Here is a sample Powershell script you can use:

[Reflection.Assembly]::LoadWithPartialName("Microsoft.AnalysisServices")

#Get a list of installed SSAS instances on this server that are running
#We need a service to be started in order to rename the log file
$SSASServices = Get-WmiObject -query "select * from win32_service where DisplayName LIKE 'SQL Server Analysis%' and State = 'Running'"

#for each installed instance, update the logfile name

ForEach ($sname in $SSASServices)

{

# Connect to the SSAS server
$SSASServer = New-Object Microsoft.AnalysisServices.Server
$SSASServer.Connect($sname.SystemName)

#gets current filename
$SSASErrorFileName = ($SSASServer.Serverproperties | where-Object {$_.Name -eq "Log\File"}).Value

#split out the .log extension
$SSASErrorName=$SSASErrorFileName.Split(".")[0]

#rename the errorlog, appending the current date
$ErrorLogName = "msmdsrv_{0}.log" -f (Get-Date -Format 'MM_dd_yyy_hh_mm_ss')

$SSASServer.ServerProperties['Log\File'].Value = $ErrorLogName
$SSASServer.ServerProperties['Log\File'].PendingValue = $ErrorLogName
$SSASServer.Update()

Restart-Service $SSASServices.Name

}


I blogged about it at http://thomaslarock.com/2015/01/how-to-recycle-the-sql-server-analysis-services-msmdsrv-log-file/ as well.

HTH