If high availability is a requirement, we recommend using a CacheDrive VM on a host with adequate levels of redundancy (RAID storage, hot swappable redundant power supplies, etc.)  High availability solutions may also be available from your virtualization software provider.


Here are some general tips when using configuring a CacheDrive as a spare.


  1. Use warm/hot spares instead of cold spares.  With a cold spare (device is powered off until needed), the filesystem may be far out of sync when it is brought online, so it may take hours before the device is ready for use.
  2. Map all critical shares on the spare device before it is needed.  When a share is enabled on a device, the CacheDrive will need to download all of the metadata for the contents of the share before the share can be made available.  Depending on the number of files and folders in the share, this can take many hours.
  3. Consider using the spare device as an active CacheDrive.  If you have two CacheDrives and ten shares, for example, you will see better performance if one CacheDrive gives read/write access to five shares and the other CacheDrive gives read/write access to the other five.  Each CacheDrive can map the other five shares as read-only making them ready to act as a spare.