Here are a few things to check if your VM-based CacheDrive is slower than expected.


  1. Make sure that your VM host has adequate hardware.  If CPU load or memory usage is consistently high, it may be time for an upgrade.  If you have access to Morro Audit, you may check CPU load and memory usage for the CacheDrive itself in the Devices -> Status page.
  2. Use the fastest (random read/write) available storage for the OS disk.  Two-disk installations can have separate OS and data disks, so for optimal performance, use direct attached SSD for the OS disk.  The data disk can use slower storage.  We highly recommend against using SAN for the OS disk.
  3. Some customers have seen a significant performance increase when switching from thin to thick provisioned drives.  If you have sufficient space for your VM images, try using thick provisioning, which will pre-allocate the needed disk space.
  4. Run diagnostics software on the storage backing the VM.  Storage issues, such as degraded RAID arrays or high reallocated sector counts, can have a huge effect on CacheDrive performance.
  5. Check if any security or anti-virus software may be scanning the VM disk image.
  6. If the CacheDrive seems to be operating normally but transfer rates are lower than expected, make sure that the virtual network switching is properly configured.  For example, the VM may be on a 10 GigE virtual switch, but if a 1 GigE switch sits between the VM and client PC, then performance will be limited to 1 GigE speeds.  If the virtual switch has a 1 GigE management port, verify that CacheDrive traffic is not routed through this port.