![]() ![]() We've run into the biggest problems with that when running CHECKDBs or when customers have very large active data sets that can overrun the cache. If a significant bit of IO ends up coming from the back-end SATA disks, whether because you're churning through the cache or the IO is classed as sequential and goes straight there, performance can tank, since 12 SATA disks can only deliver so much performance. The auto-tuning is just moving data in and out of the cache and directing sequential IO to the SATA.Īs iannoble pointed out, write performance is generally very good, since it writes to NVRAM, and reads are also fantastic provided they come from cache. There are back-end SATA disks (12 unless you add a capacity shelf, I believe), and then an all-flash cache. Having said that, there are not "tiers", per se, at least not in the sense of traditional tiered storage like EMC. We have a bunch of Nimbles in our customers' environments, and depending on your performance requirements, they can be hard to beat for performance/price. It's 8kb as that's the paging size that SQL uses, they work off that not the allocation unit size to maximise performance.Ĭompression rates and cache hit % are very high, highest out of all the types of workload that have going to it. Those profiles are optimised to get maximum perf for SQL for their hardware, they've been collecting data via their cloud service for 5 yrs now so they've tuned these over the years to optimise performance. ![]() Performance profiles wise, you store SQL data on volumes set to use SQL data profile (diff profiles for diff versions of SQL) and same for log files. I have Nimble for general workload and SQL / databases is one of the biggest areas of improvement vs enterprise storage that didn't have any flash.ĭata is written to NVRAM then flushed to disk, so has very fast write performance (good for SQL, it uses same type of filesystem as NetApp, but wrote themselves to overcome some of the shortcomings / optimise for flash), reads are either from flash cache (has various clever stuff going on to maximise cache hit rates) or spinning disk. ![]()
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