SAS or SSD for a Big Forum on Servint?

[p4guru]

Yeah... we have a huge amount of unused overhead (I don't like upgrading servers very often). I'm not 100% sure how it would perform with a degraded disk array (so far none of the 48 drives in our cluster have failed [6 drives per server, 8 servers]), but it should be fine. Our disk i/o peaks at around 1% capacity, so even if it had a 5% temporary overhead of rebuilding a replaced drive on a single machine, it should be fine. You could also route requests around that machine until it was done rebuilding if you had to, but I don't think it would be necessary.

The beauty of MySQL cluster and in memory storage

 

[p4guru]

Looking closer to the original poster's link to ServInt plans, the Flex Pro v3 uses E5-2640v2 processors and thus the platform would utilise E5 technology like Intel DDIO http://www.intel.com/content/www/us/en/io/direct-data-i-o.html which from benchmarks allows fast SAS 15K disks to push latencies at least closer to a regular SSD in the right SAS 15K Raid configuration as Intel DDIO bypasses the memory system and operates via processor's faster processor cache area.

Intel created Intel DDIO to allow Intel® Ethernet Controllers and adapters to talk directly with the processor cache of the Intel Xeon processor E5 family and Intel Xeon processor E7 v2 family. Intel DDIO makes the processor cache the primary destination and source of I/O data rather than main memory, helping to deliver increased bandwidth, lower latency, and reduced power consumption.

Video explaining Intel DDIO http://www.intel.com/content/www/us/en/io/direct-data-i-o-chalk-talk-demo.html as well as Intel Integrated IO http://www.intel.com/content/www/us/en/io/xeon-e5-workstation-integrated-io-video.html

So SAS 15K option on the Flex Pro v3 plan MAYBE enough for your needs. So the extra $200/month more for 180GB SolidFire option doesn't seem as attractive (with 32GB ram base).

edit: Intel E5s are beasts for performance, using dual Intel Xeon E5-2650 myself - avatar and username explain it all

 

[digitalpoint]

edit: Intel E5s are beasts for performance, using dual Intel Xeon E5-2650 myself - avatar and username explain it all

Agreed... I'm using a very similar CPU (same number of cores, just clocked a little faster) in my servers... dual E5-2680 in each.

 

[WSWD]

I suppose it doesn't matter if you aren't buying them and it doesn't cause any downtime for your site...

Well that's what this entire thread is about. The OP is asking which is better in his Servint dedicated server. He's not making trips to the datacenter or purchasing drives.

And I was only speaking of consumer SSD failure raid compared to enterprise SAS drives (which are roughly the same price). I've seen/heard of very few enterprise SSD drives in web hosting companies simply because they are literally thousands of dollars for a single drive.

That's apples to oranges unfortunately. You just can't compare the two. We use nothing but Intel enterprise SSDs, and like I said, we have never had a failure. For that matter, we have clients specifically request consumer SSDs in their dedicated boxes (cost), and the same thing. Not a single drive failure...ever. The RAID cards are failing long before the drives...though not sure if that's a plus for the drives or a minus for the RAID cards. We also have yet to have a drive reach its EOL.

It's not 8x's the cost either...not with any drives I've ever bought. Intel enterprise SSD's are around $1-2/GB, where hot-swappable 15k enterprise SAS's are around $0.50+/GB, and that's on the cheap end.
But it would take way more than 2-4x's the SAS drives to come anywhere close to the performance of the SSD's. So on an equal cost/storage basis, you're still getting better performance for price out of the SSDs....hands down.

 

[Anthony Parsons]

Question on this... specifically ServInt plans. I have the entry level Flex Express with 32Gb RAM... it works great with 500 - 600 online, though with about 70 members it starts to drag a bit and load increases. At a guess, load increases on CPU because it only uses a standard SATA drive.

I honestly think the CPU and RAM are fine, but the 5200rpm SATA causes more issues for other resources, thus I'm thinking about just upgrading to either SSD or their cloud SSD.

My question: Their cloud SSD for that server has 1800 Iops guaranteed, 4500 burst. Obviously this is a full scale cloud, RAID / redundancy setup, but the cost is $100 for 60GB. Wouldn't upgrading to the single 100Gb SSD for $75 a month, give me far better IOPS, considering everything is backed up daily as already is with my single 5200 drive used?

 

[WSWD]

Your problem is likely running the single drive, and I'm honestly shocked that things work great with 600 people online. Truly shocked. There are a battery of tests you can run (iowait, iotop, iostat, for example) to see if i/o is the culprit, but I would bet a ton of money that it is. You have plenty of RAM, a heck of a quick CPU, and a really slow (I'm assuming it's a 7200rpm drive, not an old 5400rpm) drive.

RAID anything is going to increase your performance (and I would never recommend running without RAID anyway, but you know that I'm sure), but yes, the SSD drive should be a massive increase in performance for your forum. I personally would stick with the dedicated server over the cloud, because the resources are all yours. No matter how you slice it, a cloud/VPS/whatever is still "shared hosting" in a sense. The cloud drive array is probably going to be faster as far as i/o is concerned (perhaps a lot) than your single SSD drive, but I would still stay on the dedicated box. Ultimately, if your forum builds more and gets really busy, if the SSD drive doesn't cut it any longer, then you put 4 in a RAID10 array and call it a day. Not a big deal.

And to answer your other question, yes. Even a cheap consumer-grade SSD is going to get you around 50,000 IOPS (random). 1800/4500 is nothing.

If you've been a good long-term client, you might ask for a discount on the drive too. $75 for 100GB drive is insanely expensive. I mean hell, you can buy a 160GB Intel enterprise drive for under $150 these days, even cheaper if you buy in bulk. A <2 mo. ROI on the drive is a tad bit ridiculous. Never hurts to ask. If they see that you're interested in upgrading, it likely means you're happy, and plan on sticking around for a bit.

 

[Anthony Parsons]

Thanks @WSWD and yes, sorry, it would be a 7200 and not a 5400. Was on a different train of thought. The 600 online though is more guests... usually only 50 - 80 members logged in, the MySQL usually starts to fall over around 700 - 750 online getting caught up in a script somewhere trying to read / write to the DB.

I'm in two minds at present, whether to upgrade to the single SSD (cheap option) OR shifting to the pro option, RAID1, and either doing as discussed above, being the 150GB 15k SAS or the 100GB SSD. Again though, $100 difference a month in pricing between those.

Food for thought...

 

[rdn]

The 600 online though is more guests... usually only 50 - 80 members logged in, the MySQL usually starts to fall over around 700 - 750 online getting caught up in a script somewhere trying to read / write to the DB.

Install BD Cache and Xen Cache, will help you save a lot.

 

[Anthony Parsons]

I have caching at all levels already... both server and browser, along with Google Pagespeed doing it's thing extremely well.

 

[WSWD]

@Anthony Parsons We have to preach RAID because it's the right thing to do. But in reality, if you can suffer a small amount of downtime while your drive is being replaced, and you can restore things relatively quickly, you're going to be fine with a single drive. If you aren't running a business, is a half day of downtime going to matter? As I think I mentioned earlier in this thread, I have never had a SSD drive fail...ever. Our RAID cards fail before the drives do. Do they fail? Sure! I've seen the reports. But the odds are in your favor generally speaking, and it's just a matter of having the drive replacd quickly so you can restore.

A single SSD drive is going to crush the SAS 15k array in RAID1 in disk i/o, and in IOPS, it isn't even fair to begin a comparison. Pretty easy decision, in my opinion.

 

[Anthony Parsons]

Thanks... ok, I will start small and see how it goes with a single SSD using the same CPU and RAM.

 

[Anthony Parsons]

I was hoping that my current setup would get me over a million posts before upgrading, but now having someone confirm my own thinking on this... changing to SSD may get me beyond that, and still cheaper than having to upgrade to octa core setups with RAID and such. Hopefully then the forum makes more $$$ to adequately cover that cost. Changing to SSD keeps me just under $300 a month, where Flex Pro, 64Gb RAM using 100Gb SSD in RAID1 ups things to $500 a month. I prefer to keep that difference a little longer.

 

[Anthony Parsons]

Ok... WOW, just WOW. Changed to single SSD and my load averages with 500 online have gone from 1.x across the board, to 0.3 averages. Looking at all the commands running, nearly all have decreased massively in CPU and RAM... so removing that big bottleneck from SATA to SSD had a huge impact, massive.

Thanks for your help with this @WSWD, much appreciated.

 

[Xon]

@Anthony Parsons We have to preach RAID because it's the right thing to do. But in reality, if you can suffer a small amount of downtime while your drive is being replaced, and you can restore things relatively quickly, you're going to be fine with a single drive. If you aren't running a business, is a half day of downtime going to matter? As I think I mentioned earlier in this thread, I have never had a SSD drive fail...ever. Our RAID cards fail before the drives do. Do they fail? Sure! I've seen the reports. But the odds are in your favor generally speaking, and it's just a matter of having the drive replacd quickly so you can restore.

Modern Retail Non-sandforce* SSDs typically have a return rate somewhere around ~1%, which is vastly better than hard drive return rate of ~5% return.

*Depending on the model line, Sandforce SSDs can have upto a 52% return rate. (ref)

And if you are worried about single drive failure, then run 2 SSD drives in RAID1.

A single SSD drive is going to crush the SAS 15k array in RAID1 in disk i/o, and in IOPS, it isn't even fair to begin a comparison. Pretty easy decision, in my opinion.

Storage performance for Cloud solutions has always been a major limiter. SSDs allow companies to buy 1-2 SSDs instead of paying for a bank of 40-60 SAS drives for equivalent performance.

And 40-60 SAS drives pull a pricy amount of power if you don't have a sweetheart deal for power.

 

[WSWD]

I was hoping that my current setup would get me over a million posts before upgrading, but now having someone confirm my own thinking on this... changing to SSD may get me beyond that, and still cheaper than having to upgrade to octa core setups with RAID and such. Hopefully then the forum makes more $$$ to adequately cover that cost. Changing to SSD keeps me just under $300 a month, where Flex Pro, 64Gb RAM using 100Gb SSD in RAID1 ups things to $500 a month. I prefer to keep that difference a little longer.

Good stuff!!! Glad to hear it took care of the issues.