VirtuCache Reduces Latency of Dell ME4024, ME4084, and ME4012 Storage Arrays

The Virtunet Difference

The customer selected VirtuCache because:

VirtuCache is the only solution in the market that improves storage performance without requiring a replacement of customer's storage arrays.

The other alternative was to replace all their Dell ME4 storage arrays with a faster All-Flash array like the Dell EMC PowerStore, which would have been very expensive.

February 18, 2022: United Arab Emirates.

Virtunet Systems develops VirtuCache software. VirtuCache improves the storage performance of VMware VMs by caching all VM data (read and write operations) to in-host SSD or RAM.

We deployed VirtuCache software at the Al Futtaim Group to improve the storage performance of their Dell ME4 appliances – ME4024, ME4012, and ME4084.

Based in Dubai, Al Futtaim is one of the largest trading companies in the Middle East.

They have a number of satellite offices that require only two ESXi hosts but large amounts of storage, at each location. Dell ME4 is a reasonably priced storage array on the market. Depending on the satellite office’s capacity needs, Al Futtaim went with either a 12-disk 2u Dell ME4012, 24-disk 2u ME4024 or 84-disk 4u ME4084 storage appliance per location. All storage appliances are connected to a 2-host ESXi cluster at each office.

High VMware Disk Latency in Dell ME4 Because of a Weak Controller

The customer’s ME4012, ME4024, and ME4084 appliances were all-Flash, yet they were experiencing high disk latencies. This was because the controller on Dell ME4s are not very powerful. Typically, storage appliance controllers use powerful x86 processors, however to keep the ME4 appliances cheap, the controller processors in the ME4s are weaker ASICs manufactured by Seagate and not x86 processors. As a result the ME4 controllers choke when large amounts of small block IO is transmitted through it, as was the case at the customer.

How VirtuCache Reduces LatencY of Dell ME4 Appliances?

VirtuCache automatically caches all storage IO (reads and writes) from VMware VMs to ESXi host SSD or RAM. So all reads requested by VMs are serviced from in-host SSD or RAM and all writes from VMs are written to the same in-host SSD / RAM as well. So most of the storage IO processing is offloaded from SAN array controllers to ESXi host CPUs. Since ESXi host CPUs are more powerful and usually underutilized, this strategy of using VirtuCache to relieve pressure on SAN array controllers and improve IOPS and latencies works very well for Dell ME4 appliances.