Sun Adding Flash Storage to Most of Its Servers

BobB-nw writes "Sun will release a 32GB flash storage drive this year and make flash storage an option for nearly every server the vendor produces, Sun officials are announcing Wednesday. Like EMC, Sun is predicting big things for flash. While flash storage is far more expensive than disk on a per-gigabyte basis, Sun argues that flash is cheaper for high-performance applications that rely on fast I/O Operations Per Second speeds."

Comments

Write cycles. again.

[Amiga Lover]

Cue up 20 comments going "But what about the limited write cycles, these things will fail in a month" and 500 comments replying "this is no longer an issue n00b"

Re:Write cycles. again.

[morgan_greywolf]

You forgot the 1000 comments prognosticating about SSDs replacing HDDs permanently "any day now" with the added bravado of saying "I knew this would happen! See, I told you!" with 3000 comments replying 'Yeah, but price/performance!", all of which will be replied to with "but price/performance doesn't matter, n00b. Price makes no difference to anyone."

Then, in a fit of wisdom, a few posters, all of whom will be modded down as flamebait, will say "There's room for both and price/performance does matter, at least for now."

Two layers, but not those ones

[clawsoon]

We are going to have two layers, but they'll be deeper in the filesystem than that.

High frequency, low volume operations - metadata journalling, certain database transactions - will go to flash, and low frequency, high volume operations - file transfers, bulk data moves - will go to regular hard drives. SSDs aren't yet all that much faster for bulk data moving, so it makes the most economic sense to put them where they're most needed: Where the IOPs are.

Back in the day, a single high-performance SCSI drive would sometimes play the same role for a big, cheap, slow array. Then, as now, you'd pay the premium price for the smallest amount of high-IOPs storage that you could get away with.

Re:I'm surprised that it is big enough to talk abo

[gbjbaanb]

"Adding a flash storage option" is pretty much an engineering nonevent but as a marketing event its a magnificent and almost unbelievable paradigm-shift approach to a massive problem that's been crying out for a reliable storage-based performance solution for years.

Re:We are going to have two layers of storage

[dgatwood]

Because write caches in RAM go away when your computer crashes, the power fails, etc. Battery-backed RAM is an option, but is a lot harder to get right than a USB flash part connected to an internal USB connector on a motherboard.... In-memory write caching (without battery backup) for more than a handful of seconds (to avoid writing files that are created and immediately deleted) is a very, very bad idea. There's a reason that no OS keeps data in a write cache for more than about 30 seconds (and even that is about five times too long, IMHO).

Write caching is the only way you can avoid constantly spinning up the disk. We already have lots of read caching, so no amount of improvement to read caching is likely to improve things that dramatically over what we have already.

Even for read caching, however, there are advantages to having hot block caches that are persistent across reboots, power failures, crashes, etc. (provided that your filesystem format provides a last modified date at the volume level so you can dispose of any read caches if someone pulls the drive, modifies it with a different computer, and puts the drive back). Think of it as basically prewarming the in-memory cache, but without the performance impact....