Increasing Performance By Using "Small File Caching"
Posted by , Last modified by on 08 August 2013 03:27 PM
IceWarp is almost completely database driven with the main exception of the actual mail files themselves. In larger mail stores this can lead to a higher disk I/O as the mailboxes are being loaded through various services. Along with the actual mail file itself there are other files such as the index file, flags file, and others that keep track of the mailbox and message properties. Each of these files can be opened in a single IMAP call when retrieving mail and folders or loading the account. On a busy server this can add up and potentially cause performance decreases since the disk I/O is higher than normal.
To combat this possibility we implemented the "Small Files Cache" so the calls would no longer call the disk directly and instead just receive the data from memory. For increased performance it is recommended to use the cache if you have at least 8GB of memory on the server. To enable small files caching please follow the steps below.
** Please keep in mind this cannot be done if the servers are in a load balanced or clustered setup **
1. Open the administration console
2. Go to [File, API Console]
3. In the search field type "small". This will bring up three results.
4. The first entry returned would be "smallfilescache.size", in the value field double-click and now enter the amount of memory you wish to allocate for this cache. ** We recommend 1GB **
5. You then can save the changes by pressing OK.
You will see other options such as:
Smallfilecache.Maxsize - This will be the maximum allowed size of any file to be cached. This is currently set to 3MB and is the recommended size.
Once the settings are saved you should restart your SMTP service to apply the changes. Once this is done you will no longer be calling these mailbox files directly and instead will be pulling the data from memory.