Need to Improve Disk Utilization on XenServer 7.2
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@jmoore said in Need to Improve Disk Utilization on XenServer 7.2:
@scottalanmiller said in Need to Improve Disk Utilization on XenServer 7.2:
@krisleslie said in Need to Improve Disk Utilization on XenServer 7.2:
Scott I knew it was vast difference but not 100x!!!! Dude a 4 ssd raid 10 is Basiclally all you need !!!
Absolutely, that's why no one uses RAID 10 for SSDs, doesn't make sense as the leap in performance is so big. That's why RAID 5 is about all that is used.
If you used 4 ssd in a raid 10 do you still get ever increasing levels of performance?
RAID is RAID. That the disk is SSD isn't a factor to the RAID system.
What can be a factor is if you use a RAID controller that caps out lower than your RAID subsystem.
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@krisleslie said in Need to Improve Disk Utilization on XenServer 7.2:
@scottalanmiller
Hey Scott, I'm going to switch my SATA 7200 RPM spinning rust probably tonight. I'll go ahead and switch to a SSD (luckily I have a bunch sitting around). With that in mind, I'm trying to wrap my head around the performance impact per machine with SSD vs a HDD. I realize the RPM's drop per "vm" I have with spinning rust. Does my IOPS drop per vm with SSD?No, SSDs do not have contention.
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@jmoore
In short, yes RAID 10 in SSD would be astronomical faster. I think looking at it like this,
4 spinning rust HDD's at 7200 RPM will only net you a max of 400 IOPS, you can keep adding more HDD's in pairs and keep improving the speed. I assume that doesn't include overhead. I mean if you got a server and just want pure storage first, then speed, then sticking with RAID 10 allows you to keep incrementally improving.But when I took that into context in what Scott is saying, its like I would have use like 10 arrays of hard drives to equal the performance of 1 SSD! But this also increases risk, what if a drive fails! That's a lot of drives to baby sit!!!!
I did my digging around 550 MB/s is roughly where most consumer ssd drives and I assume some enterprise drives that don't use nve cap off at. That's with a conservative base of 10,000 IOPS and goes up to 2 Million IOPS!!!!!!!
[https://kb.sandisk.com/app/answers/detail/a_id/16376/~/sandisk-ultra-ii-ssd-specifications](link url)
I guess looking at it from a different perspective, I would find little need for many small companies to ever want to go past 4 SSD's with RAID 10.
To get the equivalent of that speed, you would have to stuff so many internal and external RAID controllers, you would have paid well more than needed to! Even if you went 15K SAS!
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@krisleslie said in Need to Improve Disk Utilization on XenServer 7.2:
Also just to give some context, on my two Dell R530 @ work (thank God remember those oldy goldy days SAM I had haha), I went with SAS 7200's with my H700 512 MB Cache. The thing runs like a champ with just my four 2 TB HDD's in Raid 10. I have literally no IOPS problems that I've experienced. I have about 30 VM's running. With that in mind, does it make sense at work to consider the swap to full SSD?
So each NL-SAS there has 20% more IOPS than its SATA counterpart. Then RAID 10 on top of that. Then the "million IOPS" cache on top of that. Your base RAID there is getting nearly 5x the IOPS of your new machine, and then that cache makes it act many, many times that size. It's dramatic.
As far as if it is worth moving to SSD, all depends on if more IOPS would be beneficial or not. If you have plenty, what value would faster storage bring?
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@krisleslie said in Need to Improve Disk Utilization on XenServer 7.2:
I guess looking at it from a different perspective, I would find little need for many small companies to ever want to go past 4 SSD's with RAID 10.
Why do we keep mentioning SSD in RAID 10. Don't even look at that. Three SSD in RAID 5.
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Little value I think, but the NVR still needs to be tuned. We keep running into errors but it seems that UBNT NVR is a ram hog, so in theory just slapping an additional 16 GB of RAM to it will make it perform better. We have about 3-4 people simultaneously getting into the system. It's but with 4 cores, 16 GB RAM, 1 TB of space. I find we are just at 500 GB of space of usage.
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@krisleslie said in Need to Improve Disk Utilization on XenServer 7.2:
Little value I think, but the NVR still needs to be tuned.
SSDs don't need to be tuned here. It's like talking about how you have to tune your muscle car, but then deciding to get a rocket itself. But then feeling like you need to "tweak" the rocket, even though a minute ago a muscle car was going to do the job.
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Scott I think many of us have it implanted in our head with spinning rust to continue to use RAID 10 as it felt the most safe and easy to scale
Honestly, I'm still trying to debate if RAID 5 is worth it vs RAID 1 with SSD's in mind. It's an extra cost, what benefit does it bring? I've only had to deal with RAID 5 on my old server, and I nuked it and never looked back, went with RAID 10 on spinning rust.
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@krisleslie said in Need to Improve Disk Utilization on XenServer 7.2:
Honestly, I'm still trying to debate if RAID 5 is worth it vs RAID 1 with SSD's in mind.
If you don't need the capacity, then no, stick with RAID 1.
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@krisleslie said in Need to Improve Disk Utilization on XenServer 7.2:
I've only had to deal with RAID 5 on my old server, and I nuked it and never looked back, went with RAID 10 on spinning rust.
Yes, but since none of the RAID 5 issues from that era exist with SSDs, that doesn't apply here.
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@scottalanmiller said in Need to Improve Disk Utilization on XenServer 7.2:
@brrabill said in Need to Improve Disk Utilization on XenServer 7.2:
@scottalanmiller said
You can also install the GUI on the server and have local management tools. Obviously managing purely remotely is better. But as this is a desktop anyway, local management tools are not out of the question and you can switch later once you are comfortable with it. There is no lock in to your GUI or tools choices like with Hyper-V.
"Obviously"
Hey do you consider cockpit a GUI?
Yes, do you consider it local?
I don't consider it a GUI like the traditional GUI that sits on the physical box, aka CInnamon or Windows.
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Scott how will the migration from XenServer to KVM go?
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@brrabill said in Need to Improve Disk Utilization on XenServer 7.2:
@scottalanmiller said in Need to Improve Disk Utilization on XenServer 7.2:
@brrabill said in Need to Improve Disk Utilization on XenServer 7.2:
@scottalanmiller said
You can also install the GUI on the server and have local management tools. Obviously managing purely remotely is better. But as this is a desktop anyway, local management tools are not out of the question and you can switch later once you are comfortable with it. There is no lock in to your GUI or tools choices like with Hyper-V.
"Obviously"
Hey do you consider cockpit a GUI?
Yes, do you consider it local?
I don't consider it a GUI like the traditional GUI that sits on the physical box, aka CInnamon or Windows.
But do you consider it local? You asked me if it was considered a GUI (by me), I presume because I mentioned that you don't want a local GUI.
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@krisleslie said in Need to Improve Disk Utilization on XenServer 7.2:
Scott how will the migration from XenServer to KVM go?
I've not done it. We rarely migrate, we build new. We are a DevOps shop, there is no reason to ever migrate in the modern DevOps world.
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@scottalanmiller said in Need to Improve Disk Utilization on XenServer 7.2:
@brrabill said in Need to Improve Disk Utilization on XenServer 7.2:
@scottalanmiller said in Need to Improve Disk Utilization on XenServer 7.2:
@brrabill said in Need to Improve Disk Utilization on XenServer 7.2:
@scottalanmiller said
You can also install the GUI on the server and have local management tools. Obviously managing purely remotely is better. But as this is a desktop anyway, local management tools are not out of the question and you can switch later once you are comfortable with it. There is no lock in to your GUI or tools choices like with Hyper-V.
"Obviously"
Hey do you consider cockpit a GUI?
Yes, do you consider it local?
I don't consider it a GUI like the traditional GUI that sits on the physical box, aka CInnamon or Windows.
But do you consider it local? You asked me if it was considered a GUI (by me), I presume because I mentioned that you don't want a local GUI.
No I am just wondering if someone said "I installed the GUI for FEdora server" if you would think they were talking about cockpit.
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@brrabill said in Need to Improve Disk Utilization on XenServer 7.2:
@scottalanmiller said in Need to Improve Disk Utilization on XenServer 7.2:
@brrabill said in Need to Improve Disk Utilization on XenServer 7.2:
@scottalanmiller said in Need to Improve Disk Utilization on XenServer 7.2:
@brrabill said in Need to Improve Disk Utilization on XenServer 7.2:
@scottalanmiller said
You can also install the GUI on the server and have local management tools. Obviously managing purely remotely is better. But as this is a desktop anyway, local management tools are not out of the question and you can switch later once you are comfortable with it. There is no lock in to your GUI or tools choices like with Hyper-V.
"Obviously"
Hey do you consider cockpit a GUI?
Yes, do you consider it local?
I don't consider it a GUI like the traditional GUI that sits on the physical box, aka CInnamon or Windows.
But do you consider it local? You asked me if it was considered a GUI (by me), I presume because I mentioned that you don't want a local GUI.
No I am just wondering if someone said "I installed the GUI for FEdora server" if you would think they were talking about cockpit.
Most people mean the desktop GUI, so that you can hook up a monitor. Cockpit cant be used on a local monitor without another GUI existing that is local. But that's not what you asked me.
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@brrabill
I'm doing my research to get on KVM. I might go with Ubuntu for my home use. I'm still semi-noob. -
@krisleslie said in Need to Improve Disk Utilization on XenServer 7.2:
@brrabill
I'm doing my research to get on KVM. I might go with Ubuntu for my home use. I'm still semi-noob.Avoid using Ubuntu. It's unnecessarily complex. Stick with Fedora, keep things simple.
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You start playing with Ubuntu, and the next thing you know you get sucked into thinking two year old LTS releases are acceptable to deploy in production.
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The one place that Ubuntu really rocks is if you are builing an LXC/LXD host.
