Flash storage widely used, with 60% running an SSD tier

Flash use in storage is now common, with 60% using an SSD tier, but where to put that flash – server, array or appliance – is still a dilemma

Flash storage is now used by the majority of organisations, with 60% reporting the presence of a flash solid-state drive (SSD) tier in their storage infrastructures, according to an exclusive TechTarget survey published in Storage magazine.

The survey found that 53% of the respondents had tiered storage in place, 60% of which used flash as an SSD tier 0. That figure has more than tripled from 17% in 2009.

The survey also asked, for the first time, where organisations had implemented their SSD tier. This is a common question for IT managers. The choices available are to put flash in the server in PCIe card format; install it in a discrete all-flash array; or incorporate it into an existing array with spinning disk or purpose-built HDD/SSD array.

Flash SSD tier

The most popular choice among survey respondents was the latter, with 67% reporting that they had introduced an SSD tier alongside spinning disk.

Given that the market for purpose-built hybrid flash arrays is quite immature, that probably means they have installed flash into existing storage arrays. That in turn probably means it is something of a stop-gap measure. 

There are performance benefits, but these are likely to be limited as existing storage array backplanes and controller architectures are not designed for the speeds of flash.

Server-based flash

The second most popular location for flash was in the server, cited by 33% of respondents. 

The advantages of this approach are that flash is located close to the server that requires the data, rather than at the other end of the storage network. In some cases flash can reduce latency even further by operating as server memory. 

Disadvantages include that server flash can become siloed in a server, which raises potential data protection issues, although this is changing with the development of ways to share server flash.

All-flash array

The third most popular location for an SSD tier was in a dedicated all-flash array, cited by 20% of those surveyed. 

These have become a significant choice for users that want guaranteed performance from their flash, but products are only available from start-ups currently, though a shakeout in the market is likely to take place.

Most users now utilise automated storage tiering functionality to move data between tiers. More than half (54%) do this, which is slightly more than double the number that did in a similar survey in 2011.

The most common spinning disk drive type, according to respondents, was 15,000rpm SAS (40%), with 15,000rpm Fibre Channel the second most popular (20%).

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