Below is a collection of statements I have came across whilst doing a technical due diligence on Nimble Storage, along with some observed after becoming a Nimble customer.
They are listed here to benefit people performing a similar exercise.
As an aside, when performing due diligence on any product, I strongly advise anyone to obtain information direct from the manufacturers (not resellers) and if possible speak to existing customers.
“It only uses commodity hardware so why does it cost that much?" Outwith their being one set of hardware that is all designed and tested to work together, their value, which is a growing trend across all storage vendors, is primarily in software (how well they handle SSD caching, the quality of the disk subsystem) in addition to all the backup support.
“They are a startup company so not as mature as existing providers” Nimble was founded in 2008 by veterans from NetApp and shipped their first array in 2010. Their product has been in the field for 5 years.
“It uses Supermicro hardware so won’t be as reliable as custom hardware” Supermicro is enterprise grade, who are even partners in VMware’s EVO:RAIL product.
Reliability stats:
99.9997% uptime across their entire customer base (excluding issues that are not related to the Nimble such as power cuts, human error - data between July 2012 to November 2013).
“Their controllers are not active / active” The traditional reason for having active / active (to minimise latency) just don’t apply to Nimble as the SSD already provides ultra low latency performance.
Further information: http://www.nimblestorage.com/blog/technology/performance-data-integrity-and-controller-architectures/
“It doesn’t do de-duplication” This is true. It does, however, do compression, and you can use it without worrying about it degrading system performance.
Compression ratios vary as it does with de-duplication, 30-40% savings are typical.
It does also have full space efficient snapshot capabilities, to reduce disk space utilisation further.
“It doesn’t scale” Nimble is one of the most scale up or out product I have come across. It is fully modular so you don’t have to replace the entire unit to upgrade capacity or performance.
With the recent addition of fibre channel, it can scale all the way up to large enterprises in terms of capacity, IOPS and consistent latency.
“It doesn’t do NFS so won’t work as well in VMware” Whenever I have seen people say NFS is best for VMware, the main reason they give is the ability to make storage volumes smaller or larger, and to add the volumes to all hosts at the same time.
For the past 1 year I have used NFS within VMware, having used iSCSI previously.
Adding the volumes to all hosts at the same time was a much welcomed feature with NFS. Nimble can also do this, using its vSphere integration.
Making volumes smaller on the fly was also welcome initially, but it is very rare that this was an operational requirement, thus it is a feature that I will not miss.
Sometime in the next 12-18 months VVols from VMware will be mature enough to use, and give iSCSI additional management capabilities.
“It uses cMLC SSD drives” Nimble use SSD drives from the manufacturer widely recognised as being beet in class for reliability, Intel (http://info.nimblestorage.com/rs/nimblestorage/images/nimble-storage-sb-intel.pdf).
SSD technology is constantly evolving, cMLC is now the choice of several storage vendors including established players such as HP 3PAR, and newer players such as Pure (which is an all flash array, give a good explanation on why here http://www.purestorage.com/blog/pure-mystery-series-part-2-emlc-vs-consumer-mlc/).
Before any optimisations that vendors make that to extend this (e.g. 3PAR got this to 2.5 full writes/day), cMLC drives have a 5 year lifetime rating when performing 1 full drive worth of writes per day (it is writes that determine SSD life as each cell can only be written to so many times before it can not use that cell anymore).
In relation to Nimble, which has arrays in the field that are 5 years old, it is designed to use SSD drives efficiently, SSD is used principally as a read cache which don’t shorten lifespan, with a lower write activity (which primarily go to NVRAM then written sequentially to physical disk, with rlelevant data written to cache where required ref www.nimblestorage.com/blog/technology/write-cache-vs-sequential-layout/).
