SSD(solid state drive) vs HD(hard drive) for raid 5 / 6

[ShmilyTomsHardware]

Currently Reviewing our Data Center Server Builds and with all of the technological improvements with Hard Drives should we take that next step of utilizing SSD Drives for a PRODUCTION RAID ARRAY???

Looking specifically at reliability in the area of Writes on a SSD vs HD and more specifically SSD vs HD in a RAID Array since this will produce many more writes across the set of drives.

Previous research reviled that the SLC drives had a much shorter life span if large volumes of writes were taking place.

I am doing research now on the new SSD Drives to determine if this is no longer an issue. Anyone have live experience with this on a Server environment that has High usage?

 

[willard]

I don't believe there is support yet for TRIM on RAID 5 or 6. Bad idea to use SSDs without TRIM, as your performance will steadily decline and you'll use up the write cycles a lot faster.

 

[foscooter]

I am not in the IT field, but here are my opinions:

- You shouldn't need to RAID SSDs, as there performace (reads) is so much better. But, you probably should still RAID 5 or 6, since it is a server, and this could cover drive failures.

- You will loose TRIM support, an important part of SSD cycle (block) recovery.

- Being on a server, you probably will do ALOT of writes to the drives. In the long run, these will suffer. Write speeds degrade with usage and as the drive(s) fills up.

- Being on a server, users access this data thru a network, and the network won't go any faster with SSD vs. HDD. Although SSD can read up to 550MBps, even a Gigabit network won't reach that (1 Gb = 128MB : My math might be off!), and file transfers won't even come close.

In conclusion, although SSD are great in an individulas PC, I don't think they would be good on a server.

 

[ShmilyTomsHardware]

Best answer selected by ShmilyTomsHardware.

 

[ShmilyTomsHardware]

I don't believe there is support yet for TRIM on RAID 5 or 6. Bad idea to use SSDs without TRIM, as your performance will steadily decline and you'll use up the write cycles a lot faster.

That's what I was coming up with as an end result. So SSDs are not an appropriate choice for RAID'ed Server environments.

Cheers!!

 

[jbenton530]

When it comes to servers you cant have disk access that is too fast. When you look at application servers and database servers, its not about the speed of access going across the network that matters most. Servers that use SQL and even most web servers are constantly writing to storage. Even if you only add a raid SSD volume so that your pagefile is fast access, it makes a world of difference. IOPS is the name of the game in database and SQL servers. That is; Instructions Operations per Second. No matter whether you are running Microsoft SQL or something much higher end, IOPS is what makes the difference for servering hundreds and thousands of requests per socond. Servers by nature are making calculations internally before they send information out over the network. Doesnt matter if its LAN or WAN/internet. More IOPS is more better. If you are only copying files over the netowrk then SSD drivers are not really an issues. But when you are compiling and computing data, SSDs make a huge difference because of that massive increase in IOPS. Good luck.

 

[ShmilyTomsHardware]

This makes sense for single systems but not a RAID environment as of the current technology.

SSD offer a limited number of writes and with a RAID data is constantly being rewritten which would severely decrease the life of a SSD drive.

For now we are opting to continue using SAS drives with our Production Servers until SSD technology improves the life of a drive to come close to standard HD technology.

Thanks for the post.

 

[qzart]

One thing I will note from my testing is that SSD will take a huge performance hit when adding to a raid 5/6 array hell even a 1/10 but compared to a HDD SAS/SATA you will still get a huge performance hit. the problem currently is with the controller. We all know that HUGE calculations are done at the controller for these RAID levels, and that is where the bottleneck currently is. As a fellow IT pro I was an early adopter of SSD and immediately became a fan when I built my new system based off the OCZ vertex 2. I am still using that drive as my OS drive 3.5 years later and according to SSD Life (http://ssd-life.com/) I still have 9.5 years left on my SSD. When I got the system I had no problems with the drive life only being 3 years, by then (now) it would be time for an upgrade anyway. Well I don't know how most of the IT community out there is but I have beaten the hell out of this drive, probably more than most server systems and life is fine.

My conclusion and what I have put into action in my own systems is simply that SSD absolutely belongs in the data center anyone that says otherwise simply is afraid of the EARTH-SHAKING performance simply because it hasn't been around for decades. (OLD DOG CANT LEARN NEW TRICKS) SSD vs HDD is like trying to compare a Ferrari to a dump truck. If you want speed you cant compare to SSS. However if you need storage get a 3GB SATA

 

[ShmilyTomsHardware]

WOW QZART!!! Very nice - I appreciate this information and the longevity with which you have had success. This definitely changes my opinion of earlier. We currently use 3Ware Raid Controller cards and I will have to do a bit more research to be sure that these cards can handle the SSD drives correctly - but I am definitely up for the change and I have heard from several others that the SSD drives have been making marked improvements which is why I started this post in the first place.

Well I am an old dog in the IT field - and this is the reason that I am being cautious with a business decision to move forward on a PRODUCTION Server using a RAID SSD. I will put this in place on one of our Virtualization Servers to see how they really hold up in that type of environment. Once I have a year or two then I will move on to a full blown Prod Servers.

I like Ferrari's and have a few already -- in the office that is. The high performance SAS drives already make the SATA drive systems look like dump trucks.

I am seeing read write speeds up to 1GBs. Might want to recheck the comment about SAS. I realize that the SSD should outperform the SAS drives.

Thanks for this post - having real life experience to back up your point really helps and was exactly what I was looking for to help me have a solid perspective on this new technology.

Cheers,