No doubt you may have heard about the bidding war for SAN storage vendor 3PAR between HP and Dell. In case you missed it, a high-end block storage vendor (3PAR) is fetching a spectacular acquisition price that has continued to climb in a bidding frenzy, perhaps culminating this week at an astronomical $2.4B.
While there is certainly more to 3PAR than block storage, all this fuss may lead you to ask what makes block storage so desirable in customer data centers. And in the same vein, does block-access make sense for cloud storage? After all, file storage can run on similarly fast networks and offers native file sharing capability. Who needs blocks, right?
Well, the reality is that thousands of customers are purchasing block storage with good reason. While the argument between block and file can sometimes be as insightful (or uninsightful) as arguing about what type of bag to package your groceries in, I offer three of the inherent advantages of block storage that make it attractive for a variety of customer environments:
1. The ability to support any file system
Block storage supports any file system: NTFS, ZFS, Ext3, NFS, CIFS. The choice is yours for a filesystem optimized to your applications. If you are considering an on-premise gateway to cloud storage, wouldn’t you prefer to keep using the file systems you already have? With block storage, you can do just that as no “rip and replace” is required.
2. The ability to provision raw data volumes directly to applications
Many applications such as databases benefit from raw volumes that do not have the overhead of a file system. In fact, without the additional overhead, performance naturally improves. If you are using local copies of data that are replicated to cloud, it makes sense to optimize the performance of local access. If you are using server virtualization, VMware allows raw device mappings (RDM) from SAN attached raw volumes that minimize the I/O stack to maximize performance.
3. Benefits of block level granularity
When you are replicating data, say from a local copy of data to cloud copy, it is not always efficient to copy entire files to the cloud when only a small portion of the file is modified. For larger files especially, it is more efficient to send block level updates where a block represents only a small portion of the file. Also, with technology such as deduplication, it is more efficient to identify and consolidate duplicate blocks within files than duplicate files. See our deduplication performance blog post for more about this.
In summary, when considering deploying cloud SAN solutions or cloud storage gateway solutions, you’d be wise to consider the solution that has the maximum flexibility to meet all of your application needs, both present and future.
File or block storage? Which works best for you?
