What do you like best?
This solution allows the use off-the-shelf hardware and charges by the TB of storage. So we can throw in our own enterprise-class hardware (including SSDs) and not pay any extra based on the type of storage we use. This is the same model used with server virtualization. Keep the hardware separate from software. This is true "storage virtualization" at it's finest. The software over the years has matured to be a very robust and allows you to build a very high performing storage platform. It has all the features of any high-end SAN such as fibre channel, iSCSI, thin provisioning, storage tiering, snapshots, continuous data protection/recovery synchronous and asynchronous mirroring, performance reporting/graphing, true HA design.
You can utilise just about any storage you wish with this product such as another SAN, NAS, JBOD, FusionIO etc. If Windows can see it as a non-removable drive, you can use it with SANsymphony. Also, you can use this to mirror any of these various types of storage which is awesome for migration. Say you have an HP SAN and you want to migrate off it to your own JBOD type storage or you have 2 sites with 2 different storage SANs that you want to replicate data between. With DataCore, it is possible to mix and match just about any storage platform you want to use.
The system is designed to run on top of Windows Server OS (which can be virtual or physical) and can utilise the server's RAM to provide disk cache. This makes our 7.2K storage run really fast and allows us to use a bottom tier class of drive and get the performance of a much higher class of drive. Alos if we have to add capacity or replace drives we can just order replacement drives off the web saving us quite a bit of money. Of course, we still use "enterprise-class" drives but we don't pay through the nose to buy hardware. If we want to upgrade the Ethernet ports from 1Gb to 10Gb we just do it. Same goes for FC. If we want to upgrade from 4Gb FC to 16Gb, we don't have to do a forklift upgrade. We just buy the HBAs and we're off the to races.
The other great thing is DataCore keeps their product on VMware's approve HCL. So even if you have a SAN that falls off the HCL with VMware. If you put the storage behind DataCore you won't have to worry about VMware's HCL any longer. Because of this fundamental practice, DataCore was one of the first storage vendors to support vVOLs.
Support is OUTSTANDING and they release new updates and features frequently (sometimes almost too frequently).
What do you dislike?
There's very little that I can find in their software that I would say I dislike. Sometimes the updates are too frequent and just as we finish updating all our sites another update comes out. Due to the many, many various options for what hardware to use, sometimes it is difficult trying to figure out what hardware options are the best for the money. DataCore can help a bit with this but because they only are the software side of the solution they tend to not prefer one hardware vendor over another (they get along with everyone). They do have good documentation that covers known issues with various hardware items.
Currently, SANsymphony does HA with just 2 sets of mirrored drives/RAID sets over FC or iSCSI. It would be interesting to see if in the future they can stripe the data across 3 or more nodes to create an n+1 type configuration.
While their console allows you to connect to each of the nodes without closing the interface you have to log out and in when you switch between a different storage server groups. It would be nice if they had an interface more like vCenter to where you see all server group in a list and can just click on each group. It would be nice to be able to see multiple groups at the same time.
Recommendations to others considering the product
Obtain DCIE certification before installation, provide ample time for hardware testing/storage burn-in. Follow all DataCore's procedures for testing and certification the installation.
If possible, use Fibre Channel. iSCSI is OK but more complex and not as fast due to the overhead of TCP headers.
If it's a small site with only a couple of ESX hosts and 2 DataCore storage servers running in HA use direct connect Fibre Channel (FC switches are not needed for smaller configurations as long as you have enough ports. With quad-port HBAs that's easy to do).
Pick a storage server with lots of PCIe slots, decent CPUs and as much RAM as you can afford to help with disk caching.
Use a dedicated UPS on each of the storage servers to protect disk caching.
Don't bother with non-mirrored drives. At this cost, HA is the only way to go in my book.
What business problems are you solving with the product? What benefits have you realized?
Flexibility, performance and cost savings are the three biggest benefits for us. For sure, we would not have been able to afforded to virtualize all our locations without this product.