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Samsung ships the world's highest capacity SSD, with 15TB of storage

computerworld.com

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Re: Samsung ships the world's highest capacity SSD, with 15TB of storage

#41

Post by hyperpallium »

userbinator wrote: post #21

The 15.36TB PM1633a drive supports one full drive write per day, which means 15.36TB of data can be written every day on a single drive without failure over its five-year warranty. In other words, assuming good wear leveling, each bit can only be rewritten ~2K times, which is actually quite low for endurance... the capacity is high and they're using that to hide the fact that it's low, but if this was e.g. SLC flash…

They're not guaranteeing failure in 5 years, but are pretty sure it won't fail. If "pretty sure" is 98%, then that's 100K (or something like it, probability maths is hard).

Re: Samsung ships the world's highest capacity SSD, with 15TB of storage

#42

Post by eropple »

laurencerowe wrote: post #40
sdesol wrote: post #11

Earlier quoted context omitted.

> I thought RAID and SSD were a terrible combination Well there are different RAID settings. My product is an indexing engine (indexes Git repositories) and I've personally found RAID 0 reduces indexing time by about 30% compared to a single drive. I have a machine that has 4 SSDs running RAID 0 and I've found the performance gain after 3 SSDs is negligible. It seems like 3 SSDs running RAID 0 is the best combination…

An SSD is implemented a little like a RAID array internally. Higher capacity SSDs have more flash chips and tend to be faster. So one would expect that 2 x 128GB drives in RAID 0 to perform similarly to a single 256GB drive.

Wouldn't being able to offload to multiple SSD controllers potentially help too if that's the bottleneck?

Re: Samsung ships the world's highest capacity SSD, with 15TB of storage

#43

Post by pixl97 »

cookiemonsta wrote: post #36
ars wrote: post #17

Earlier quoted context omitted.

> The first disk died late on Friday. I had two on-hand so I casually replaced it -- and before I got back to my desk another had died. That happens very very very often. It has nothing to do with a bad batch. The second disk actually failed a while ago, but no one noticed because no one read from that part of it. When you did the rebuild you read from the failed area and woke up the failure. When you setup raid you…

Is there a well known tool to check for this?

If you use 3ware/LSI/Avago (now all Broadcom) you install the Megaraid tools and it has a scheduler that does a patrol read whenever you schedule it to. ReadyNAS devices have a similar setting that will check the disks.

Re: Samsung ships the world's highest capacity SSD, with 15TB of storage

#44

Post by seanp2k2 »

21 wrote: post #34
imaginenore wrote: post #29

Earlier quoted context omitted.

Then you have to include the connectors and buses to access the SSD as well. And it will still be in favor of microsd, which can be read by a tiny connector + tiny controller in a smartphone.

I think parent was asking if you can fit 75 microSD cards (75 * 200 GB = 15 TB) and the required connections in the form factor of this SSD.

If you're just counting the flash chips on circuit boards, I would think that you could fit many more SD innards and wire them together with some type of controller in this space. I don't doubt however that given the use-case, it has some room allocated for chips going bad, heat dissipation, etc inside. If they could have made a 20TB drive instead for the enterprise market in this form factor, they would have.

Re: Samsung ships the world's highest capacity SSD, with 15TB of storage

#45

Post by pixl97 »

zanny wrote: post #7
cm2187 wrote: post #6

Earlier quoted context omitted.

I thought RAID and SSD were a terrible combination. As if both drives do exactly the same writes at the same time, chances are they will fail at the same time. Plus most RAID controllers don't support TRIM. Has the thinking changed?

A Raid 5 could work, since you are not writing the same data. You would need a hardware coprocessor to handle generating the checksums at 4GB/s though.

>You would need a hardware coprocessor to handle generating the checksums at 4GB/s though.

A first gen i5 2.4GHz can generate XOR for RAID5 at 4GB/s. Newer generations at faster core speeds should be able to beat that significantly.

...

I went and tested this on a Intel(R) Xeon(R) CPU E3-1220 v3 @ 3.10GHz

[1053854.445872] avx : 17860.000 MB/sec

[1053854.475878] raid6: sse2x1 gen() 6554 MB/s

[1053854.492857] raid6: sse2x2 gen() 9070 MB/s

[1053854.509853] raid6: sse2x4 gen() 11273 MB/s

[1053854.526848] raid6: avx2x1 gen() 21554 MB/s

[1053854.543844] raid6: avx2x2 gen() 25152 MB/s

[1053854.560838] raid6: avx2x4 gen() 29167 MB/s

[1053854.560839] raid6: using algorithm avx2x4 gen() (29167 MB/s)

[1053854.560840] raid6: using avx2x2 recovery algorithm

Re: Samsung ships the world's highest capacity SSD, with 15TB of storage

#46

Post by kabdib »

ChoGGi wrote: post #35
rgbrenner wrote: post #4

Earlier quoted context omitted.

article says 1200MBps.. so more like 3.5 hours.

I wonder how that 1200MBps will hold up with the thermal throttling with their other V-NAND products (SM951/950 Pro), especially when doing a raid rebuild? I happen to have a 950 Pro, and normal usage keeps the temperature at reasonable levels (though I stuck heatsinks on mine), but this is much more dense (512 vs 2 on the 950 Pro).

FusionIO drives (PCIe attached flash storage) have serious heat sinks. The heat sinks are not for show.

I get about 2GByte/second sustained. It's fun :)

Re: Samsung ships the world's highest capacity SSD, with 15TB of storage

#47

Post by rsync »

cm2187 wrote: post #6
NovaS1X wrote: post #2

Impressive. First question that pops into mind is how long the rebuild time would take if one of these failed in a RAID. I can imagine it'll take a while.

I thought RAID and SSD were a terrible combination. As if both drives do exactly the same writes at the same time, chances are they will fail at the same time. Plus most RAID controllers don't support TRIM. Has the thinking changed?

"I thought RAID and SSD were a terrible combination. As if both drives do exactly the same writes at the same time, chances are they will fail at the same time."

This is a very good thought and you should be thinking it.

However, it is really only applicable to raid mirrors. Raid stripes will not have identical wear lifespans.

All of our mirrored boot devices are either:

- current intel enterprise SSD paired with the previous generation intel enterprise SSD

or:

- current intel enterprise SSD paired with current samsung enterprise SSD

That way if there is a usage related failure (or some weird firmware bug triggered by use pattern) they don't seize up identically.

Re: Samsung ships the world's highest capacity SSD, with 15TB of storage

#48

Post by rsync »

Freaky wrote: post #26
cm2187 wrote: post #6

Earlier quoted context omitted.

I thought RAID and SSD were a terrible combination. As if both drives do exactly the same writes at the same time, chances are they will fail at the same time. Plus most RAID controllers don't support TRIM. Has the thinking changed?

> As if both drives do exactly the same writes at the same time, chances are they will fail at the same time. You mean due to exhausting their endurance? This is something you monitor, you should have plenty of time to replace the drives before it becomes a concern. For other failures, how's it going to be any different from normal HD's? There's always the risk that having the same models/batches in the same conditio…

"You mean due to exhausting their endurance? This is something you monitor, you should have plenty of time to replace the drives before it becomes a concern. For other failures, how's it going to be any different from normal HD's? There's always the risk that having the same models/batches in the same conditions might lead to a cluster of failures, but RAID's still likely to save you from plenty of other failure modes."

He's talking about something else. Physical drives fail due to physical reasons, but SSDs fail for logical reasons.

A weird firmware bug or an unexpected usage pattern or wear pattern (not just burning the entire things lifetime up) can cause the SSD to die.

If you have a mirror, and you have two identical SSDs, and you produce such a condition ... then no more mirror. They both die identically.

See my response to the parent about how you can easily address this by mixing SSDs in mirrors.

Re: Samsung ships the world's highest capacity SSD, with 15TB of storage

#49

Post by userbinator »

sp332 wrote: post #37
bluedino wrote: post #32

Earlier quoted context omitted.

10,000 USD?

I don't see any SAS SSD's going for much less than $1,000/TB. Some of them are twice that! And I'm sure the density will let it command a premium by targeting users who really need more storage in tight spaces. My guess is $50,000.

On the other hand, I still remember when hard drives (the spinning platter ones) reached the $1/GB mark ~10 years ago. Now high-end SSDs are there. A billion bits of storage costing $1 is pretty amazing, I think.

Re: Samsung ships the world's highest capacity SSD, with 15TB of storage

#50

Post by _wmd »

scurvy wrote: post #25

Why SAS and not NVMe? You can buy all NVMe enclosures/servers now. Is this solely aimed at replacing drives in existing enclosures? Not much good there as most of them will be SAS6. They'll still work, but not nearly as fast as SAS12 nor NVMe.

You're asking for 2 major tech steppings in a single product. We don't even have many mass market NVMe drives yet, and that aside, they're undoubtedly pushing the limits of their existing controller tech just to handle the capacity. Has NVMe seen much enterprise adoption yet? No surprise they chose an interface to match their intended customers' existing product lines
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