Caching Needs and SSDs
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@scottalanmiller said in Caching Needs and SSDs:
Things like databases feel the caching the most. Rapid small writes.
That's why if you are running a database or other heavier IOP intensive applications, you wouldn't choose the H330. You'd put in some more money and do it right for the job.
it's also killing the SSDs.
It depends on the load, that's my point. I'm basing this on the fact that the engineer building the server is buying the right parts for the load, for the right costs.
But a H730p is a lot more money than a H330. That costs more than replacing an SSD 8 years down the road... which would have most likely needed replacement even with caching.
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@Tim_G said in Caching Needs and SSDs:
But a H730p is a lot more money than a H330. That costs more than replacing an SSD 8 years down the road... which would have most likely needed replacement even with caching.
Haven't looked, what what is the price difference? It's bigger than just cache, though, one is hardware RAID and one is software, as well.
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Just looked on xByte, the price delta is $230. And that's for the big 2GB cache model.
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@scottalanmiller said in Caching Needs and SSDs:
@JaredBusch said in Caching Needs and SSDs:
@scottalanmiller said in Caching Needs and SSDs:
Also, the need for the battery went away long ago. That's a 2000's problem.
Do what? This was a standard feature as recently as 2012 on the Dell T600 line.
Standard as a cheaper downgrade, right?
Standard as in it was the "Dell Recommended" option at the time.
And it looks like it was 2011.
And it looks like the R720xd I purchased from XByte to replace that server has the PERC H710P with a battery.
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I feel like our machines in the 2000s from HP started shipping with NVRAM. It was close to the 2000s at the least.
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@JaredBusch said in Caching Needs and SSDs:
@scottalanmiller said in Caching Needs and SSDs:
@JaredBusch said in Caching Needs and SSDs:
@scottalanmiller said in Caching Needs and SSDs:
Also, the need for the battery went away long ago. That's a 2000's problem.
Do what? This was a standard feature as recently as 2012 on the Dell T600 line.
Standard as a cheaper downgrade, right?
Standard as in it was the "Dell Recommended" option at the time.
And it looks like it was 2011.
And it looks like the R720xd I purchased from XByte to replace that server has the PERC H710P with a battery.
This page here says it uses NVCache. Why does it have a battery?
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@Tim_G said in Caching Needs and SSDs:
@JaredBusch said in Caching Needs and SSDs:
@scottalanmiller said in Caching Needs and SSDs:
@JaredBusch said in Caching Needs and SSDs:
@scottalanmiller said in Caching Needs and SSDs:
Also, the need for the battery went away long ago. That's a 2000's problem.
Do what? This was a standard feature as recently as 2012 on the Dell T600 line.
Standard as a cheaper downgrade, right?
Standard as in it was the "Dell Recommended" option at the time.
And it looks like it was 2011.
And it looks like the R720xd I purchased from XByte to replace that server has the PERC H710P with a battery.
This page here says it uses NVCache. Why does it have a battery?
Don't ask me, I am just the consumer from that point of view.
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@scottalanmiller said in Caching Needs and SSDs:
Just looked on xByte, the price delta is $230. And that's for the big 2GB cache model.
Considering the cost of the storage, $230 is nothing, and totally worth the cost for the benefit.
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@Dashrender said in Caching Needs and SSDs:
@scottalanmiller said in Caching Needs and SSDs:
Just looked on xByte, the price delta is $230. And that's for the big 2GB cache model.
Considering the cost of the storage, $230 is nothing, and totally worth the cost for the benefit.
That's my thought. It's a rare use case where the speed and protection that this adds, along with blind swap and upward system compatibility with all enterprise platforms, is a pretty big deal. Plus it offloads work from the main CPUs, which is minor.
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@scottalanmiller said in Caching Needs and SSDs:
@Dashrender said in Caching Needs and SSDs:
@scottalanmiller said in Caching Needs and SSDs:
Just looked on xByte, the price delta is $230. And that's for the big 2GB cache model.
Considering the cost of the storage, $230 is nothing, and totally worth the cost for the benefit.
That's my thought. It's a rare use case where the speed and protection that this adds, along with blind swap and upward system compatibility with all enterprise platforms, is a pretty big deal. Plus it offloads work from the main CPUs, which is minor.
I was going by buying it new on a new Dell server through Dell so the whole thing is covered by their warranty. According to just the regular site, it's over $400 more than the H330. I normally wouldn't buy a new server from Dell, and then get the RAID Controller through a 3rd party.
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@Tim_G said in Caching Needs and SSDs:
@scottalanmiller said in Caching Needs and SSDs:
@Dashrender said in Caching Needs and SSDs:
@scottalanmiller said in Caching Needs and SSDs:
Just looked on xByte, the price delta is $230. And that's for the big 2GB cache model.
Considering the cost of the storage, $230 is nothing, and totally worth the cost for the benefit.
That's my thought. It's a rare use case where the speed and protection that this adds, along with blind swap and upward system compatibility with all enterprise platforms, is a pretty big deal. Plus it offloads work from the main CPUs, which is minor.
I was going by buying it new on a new Dell server through Dell so the whole thing is covered by their warranty. According to just the regular site, it's over $1000 more than the H330. I normally wouldn't buy a new server from Dell, and then get the RAID Controller through a 3rd party.
I would never buy direct from Dell, either.
Why would you buy from dell instead of xByte?
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@Tim_G whole thing is warrantied through xByte too.
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@scottalanmiller said in Caching Needs and SSDs:
@Tim_G whole thing is warrantied through xByte too.
I don't know... I guess if xByte sells everything Dell sells, but for half the price, there's no reason to buy through Dell as far as I can tell, as long as you are getting the same warranties and support that Dell offers. Perhaps Dell should just shut down their online store and redirect to xByte IMHO.
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But hey, now I know! I suppose with xByte, no need to choose a H330 if you can get the best there is for only $200 more.
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Benefits of being part of these communities... always learning new things!
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@Tim_G said in Caching Needs and SSDs:
@scottalanmiller said in Caching Needs and SSDs:
@Tim_G whole thing is warrantied through xByte too.
I don't know... I guess if xByte sells everything Dell sells, but for half the price, there's no reason to buy through Dell as far as I can tell, as long as you are getting the same warranties and support that Dell offers. Perhaps Dell should just shut down their online store and redirect to xByte IMHO.
They are both a normal dell reseller and a refurb dell shop. The refurb have warranties and are "new" but like open box that can't legally be called new. But not used.
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@scottalanmiller said in Caching Needs and SSDs:
@Tim_G said in Caching Needs and SSDs:
@scottalanmiller said in Caching Needs and SSDs:
@Tim_G whole thing is warrantied through xByte too.
I don't know... I guess if xByte sells everything Dell sells, but for half the price, there's no reason to buy through Dell as far as I can tell, as long as you are getting the same warranties and support that Dell offers. Perhaps Dell should just shut down their online store and redirect to xByte IMHO.
They are both a normal dell reseller and a refurb dell shop. The refurb have warranties and are "new" but like open box that can't legally be called new. But not used.
A server I recently built is now 10k cheaper on xByte. (well 1.5 years ago) I guess a combination of time + xByte being cheaper.
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@Tim_G said in Caching Needs and SSDs:
@scottalanmiller said in Caching Needs and SSDs:
@Dashrender said in Caching Needs and SSDs:
@scottalanmiller said in Caching Needs and SSDs:
Just looked on xByte, the price delta is $230. And that's for the big 2GB cache model.
Considering the cost of the storage, $230 is nothing, and totally worth the cost for the benefit.
That's my thought. It's a rare use case where the speed and protection that this adds, along with blind swap and upward system compatibility with all enterprise platforms, is a pretty big deal. Plus it offloads work from the main CPUs, which is minor.
I was going by buying it new on a new Dell server through Dell so the whole thing is covered by their warranty. According to just the regular site, it's over $400 more than the H330. I normally wouldn't buy a new server from Dell, and then get the RAID Controller through a 3rd party.
Even at $400, that's the cost of one drive - for all the things you get, I'd easily do it! i used to drop $800+ on RAID controllers, to drop $400 would make me happy!
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@Tim_G said in Caching Needs and SSDs:
@scottalanmiller said in Caching Needs and SSDs:
@Tim_G said in Caching Needs and SSDs:
@scottalanmiller said in Caching Needs and SSDs:
@Tim_G whole thing is warrantied through xByte too.
I don't know... I guess if xByte sells everything Dell sells, but for half the price, there's no reason to buy through Dell as far as I can tell, as long as you are getting the same warranties and support that Dell offers. Perhaps Dell should just shut down their online store and redirect to xByte IMHO.
They are both a normal dell reseller and a refurb dell shop. The refurb have warranties and are "new" but like open box that can't legally be called new. But not used.
A server I recently built is now 10k cheaper on xByte. (well 1.5 years ago) I guess a combination of time + xByte being cheaper.
Time might be a big factor
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@Tim_G said in Caching Needs and SSDs:
@scottalanmiller said in Caching Needs and SSDs:
@Tim_G said in Caching Needs and SSDs:
Double caching seems dangerous or at least slow things down a little.
Not dangerous or slow. We do similar things for high speed websites. But in the opposite direction, of course.
Double caching is no more dangerous than single caching, if caching is dangerous, it's dangerous. If it is safe, it doesn't matter how many times you do it.
As for latency, it's not an issue and all hardware RAID systems like this do it under the hood because it's the only good way to add the SSD layer. You always want a RAM cache on the front end, and you need disks on the back end. The question is, do you want SSD in the middle or not.
If you think about the performance leap from spinners to SSD, it makes total sense to have SSD in front of them for cache. Even a little SSD helps the spinners a LOT. Same difference from SSD to RAM. RAM is orders of magnitude faster than SSD, just like SSD is over spinners. So the gains are similar. And RAM doesn't wear like SSD does, so it doesn't just speed things up but allows for fewer and more efficient writes and that means longer SSD life which actually adds reliability.
Also, cache allows writes to happen faster allowing more data to be protected before a failure.
I have a main Hypervisor running with a PERC H730p (2gb cache), configured with write-back (uses the 2gb cache) for all volumes, even the SSD SanDisk DAS Cache slow HDD volume.
But if someone has a H330 (without a cache), you can still use an SSD cache (such as with SanDisk DAS Cache) perfectly fine. You don't NEED to have the onboard RAID card cache. You can even write-through to your SSD cache volume.
Don't use DAS Cache. Western Digital had basically discontinued the product. If you rely on in within your infrastructure it means you have something on I/O path going wrong ;(
