There have been some great IT technologies and products released over the past few years with many linked with virtualization. For me one product that has really caught my imagination because of its ability to easily present and scale storage through to virtualization hosts is HP’s LeftHand iSCSI SAN product.
HP’s LeftHand iSCSI SAN offering comes from an acquisition they made just over a year ago of LeftHand Networks. This addition to HP’s StorageWorks portfolio means that they have a product to compete with the likes of Dell’s EqualLogic iSCSI offering which offers similar functionality though no Virtual SAN Appliance (VSA) option.
Whilst at the recent HP StorageWorks TechDay I had the opportunity to catch up with LeftHand co-founder John Spiers and LeftHand expert George Wagner who kindly agreed to explain what HP LeftHand is about and some of the features it provides. I’m sure you’ll find it interesting:
I particularly like the LeftHand VSA, as looking around your server room how many servers do you have containing significant amounts of disk that just aren’t being utilised? If these servers are yet to be virtualized, assuming they are able to, then here’s a good excuse to do so. After P2V’ing the server simply install VMware ESX/ESXi on it and run the HP LeftHand VSA, which will share this local disk out and combined with other servers, also running the VSA, creates a pool of shared storage for your VMs. As you probably know running your VMs across ESX hosts on shared storage means that you can start to use useful ESX functionality such as DRS, HA and FT.
So not only do you get the benefit of running your servers virtualized but the same physical server hardware they are running on is providing the shared disk storage.
Another benefit is that as HP LeftHand is running as a Virtual SAN Appliance the servers running the VSA don’t need to be the same make or model though would need to be on the VMware Hardware Compatibility list.
Through using either the LeftHand Appliance or LeftHand VSA you are given the ability to cluster together the disk storage available in each of the LeftHand nodes into pools of storage which is then in turn presented through as shared storage to servers, as mentioned above, making it ideal for server virtualization data stores.
Via network RAID the LeftHand product stripes the data across the cluster of storage nodes providing resilience against hardware failure or similar at a storage node (ie: the LeftHand Appliance or the ESX/ESXi host running the VSA) level. If you have a requirement to add more disk space to one or more of your pools of storage or you need additional storage throughput performance then simply add an extra LeftHand node. This node’s storage can then be unobtrusively added to any existing storage pools or can be used to create new pools. As this is an iSCSI based SAN when reading or writing data to a storage pool the more nodes (physical or virtual (VSA)) you have the more physical network connections you have to carry the iSCSI based traffic and this combined with there being more disk controllers to distribute the load over results in providing increased storage performance.
Add to this the fact that when you buy HP LeftHand you get licenses to enable all of its features, so there is none of the buy the base product and then pay through the nose to turn on the useful additional features, makes it an attractive storage option in my opinion.
Here’s an example of what you get when buy HP LeftHand:
Thin Provisioning – space is allocated on an as-needed basis so there is no need to pre-allocate storage.
Remote Copy – This feature provides companies with a disaster recovery (DR) and centralised management solution. The Remote Copy takes thin provisioned snapshots and replicates them between HP LeftHand SANs located at different locations (eg: same building, across town or continents).
SnapShots – This creates volume level thinly provisioned snapshots from which individual files or the entire volume can be recovered to its previous state.
For me there isn’t much to not like about HP LeftHand due to the storage flexibility and options it gives to companies. They can start small and grow their storage cluster as required or as budget becomes available.
I acknowledge that there are similar competing products out there such as Dell EqualLogic and I hope to have time to get some hands-on time with these sometime soon.
In the meantime watch this space as I have an article coming up which demonstrates the HP LeftHand VSA running across a mix of HP Proliant ML110/ML115’s. I think you’ll be impressed with what it can do even on these entry level servers.