Looking at the hardware for the VM hosts.

VM host nodes will have 1 CPU, 10 cores, 64GB RAM, 500GB SSD storage. In my mind that would allow us to run 8 VMs per node with 4 vCPU, 8GB RAM and 50GB storage per VM. Every VM will be linux/bsd.
Nodes are also easily expandable to 2 CPU, 20 cores, 128GB RAM and whatever storage that is needed (6x3.5" bays).

Does the CPU / memory /storage balance seem right for these type of applications?

Also would it be better to have VM setup with just the database or to have each type of application have their own DB inside their VM?

So which one?

• 4 VMs with different apps and one VM with the DB
• 4 VMs with different apps and DB

Alright, just to recap.

We have two options here and we could use either option depending on the VM and the application itself.

• Continuous VM replication (VM host to VM host replication?)
• Database replication (VM guest to VM guest replication)

And neither of them would require shared storage.

Is that correct?

And in the case of database replication we could also set up a load balancer and have the application running on multiple VMs (hosts) for higher performance and automatic failover.

@scottalanmiller said in Small colo infrastructure for SaaS:

@jaredbusch said in Small colo infrastructure for SaaS:

No. You are wrong. The entire word is not stateless. VM replication is easier and simpler and cheaper.

That's why I pointed out that this was specifically the standard for well made bespoke apps, which is anything but the whole world.

I see how both can work.

I think replication of the DB would be faster than continuous replication of the VM because there are less data to be changed.
Also if you have a VM of the application running on both servers and load balance you would get a higher performance and scalable solution.

@dustinb3403 said in Small colo infrastructure for SaaS:

@scottalanmiller said in Small colo infrastructure for SaaS:

@dustinb3403 said in Small colo infrastructure for SaaS:

My biggest question is why split workloads, rather than just the two servers, one acting as the active host, the other acting as the backup host.

Remove the NL Storage server entirely.

Perform continuous replication from Host A to Host B, as well as backup offsite.

Why even that much complexity? Only piece that needs replicated normally is the database.

Because you'd need to have a readily available to use infrastructure somewhere that can host said database. Which might be beyond the technical expertise at the table to configure.

I don't want to replicate the db to the cloud. I believe it will be too slow.

And I want to have the backup locally available so restores are fast - even if I will also backup to offsite at times.

Colo is 30 minute drive from our office.

@scottalanmiller said in Small colo infrastructure for SaaS:

In that case, why the live migration? Should not be needed at all, correct? If one node dies, the other just takes over?

Live migration for service, upgrades and such.

@scottalanmiller said in Small colo infrastructure for SaaS:

So a LOT of these decisions will be completely dependent upon you application architectural design. Traditional HA (which you said you don't need) and shared storage (which you think that you do) are based around the applications themselves not sharing data between nodes. But that isn't too much of a challenge for a modern application.

In many cases you would need none of these things. Two VM hosts, yes. But shared storage? Not likely. Let the database replicate and you get HA without needing shared storage or HA from the VM hosts.

That's exactly what I had in mind. The storage in the colo is for backups primarily, hence nearline.

I'm going to rent a 1/4 rack at a colocation center and put some servers there.

The purpose of this project is to host applications we have developed so our customers can use them. In the past we have mostly developed one-off intranet applications that we have installed on the customers own infrastructure and then maintained.

I feel that that is a dead end from a business point of view and it's long overdue for us to become a SaaS provider, albeit at a very small scale. Our current customers are enterprise customers but the applications themselves don't have that many users, from maybe 20 users up to about 300. In any case the applications have happily been running on single servers, without any load balancing, database clusters or other similar techniques.

First step for this project is to find an infrastructure that will get the job done without overspending but that we could expand upon. I don't feel that we need high availability from a business point of view. If we have a hardware failure though we need to be able to get up and running again in a few hours.

I'm thinking two VM hosts without HA and without running on shared storage could do that. If one host goes down we could manually fire up the backup on the other host.

This is what I had in mind:

VM host nodes will have 1 CPU, 10 cores, 64GB RAM, 500GB SSD storage. In my mind that would allow us to run 8 VMs per node with 4 vCPU, 8GB RAM and 50GB storage per VM. Every VM will be linux/bsd.

Nodes are also easily expandable to 2 CPU, 20 cores, 128GB RAM and whatever storage that is needed (6x3.5" bays).

I like the management of Xenserver so that is what I'd like to use, well actually XCP-ng.

What do you guys think?

The rate is the rate. Either you can do the job or you can't.
Rate starts counting from the time you get the call.

And as normal, higher rate for non-business hours. Extra high rate for holidays.

@travisdh1 said in Question about weather or not I should enable write-through mode on a RAID1 SSD array:

@pete-s said in Question about weather or not I should enable write-through mode on a RAID1 SSD array:

@dave247 said in Question about weather or not I should enable write-through mode on a RAID1 SSD array:

@pete-s said in Question about weather or not I should enable write-through mode on a RAID1 SSD array:

@dave247 All enterprise SSDs have power protection caps so that is an expected feature.

If the raid controller cache makes an improvement or not depends on the workload and the size of the cache.

I think the 3.84TB drives have 4GB cache internally. That's large compared to the RAID controllers cache. What do Dell recommend?

I haven't asked Dell what they recommend. The H730P has 2GB and the H740P has 8GB though.

Give them a call. A little more than 3 years ago I spec'ed a computer with 4 SATA SSDs in two RAID1 arrays and I remember that they were adamant that I get the H730P controller. Machine was an R630.

Of course they were, they're job is to sell you thing, or more expensive things, than you really need.

True, but in this case it was their tech department, not sales. But in any case, SSD technology moves fast so a lot has happened in the last three, four years.

Dell (and others) are also pretty slow in adopting new technology and it takes a while for new drives to show up in their line up so I guess the drive Dell had back then were already old.

That's why I like Supermicro - they keep up with new tech and you can mix and match to your heart's content.

@scottalanmiller said in Question about server hard drives:

xByte doesn't sell used drives. Did someone recommend used? I think just old.

Aaah, I automatically though used when I read old. My bad!

Drive reliability goes down with age, a lot. I wouldn't buy used drives to put in a new machine, not HDDs at least.

SSDs maybe - if I would know manufacturing date and how many TBWs they had before purchase. It would have to be something that's a year old or so, not 3-5 years old.

@obsolesce said in Looking at New Virtual Host Servers (ESXi):

@networknerd said in Looking at New Virtual Host Servers (ESXi):

Even though it's a small workload, I would still look at storage performance requirements closely before you make a purchase so you get the correct speed of drives. How is the OBR10 with 7200 RPM drives performing today? Would looking at 10K RPM drives improve performance and make a true business impact with your applications?

You're correct that it's important to first look at storage performance requirements closely.

OBR10 with big TB 7200 RPM drives is still slow as hell for a big hypervisor. I know this for a fact and experienced it first hand on a host with about (back then, 50) running VMs using 6x 8TB 3.5" spinners (RAID10) as the main storage for the VMs, with a bunch of 1.8" SSDs for read/write caching.

When I had the SSD caching disabled for some planned and scheduled maintenance, the whole thing crawled. You do not want to run a bunch of VMs on a few 7200 RPM drives. You can't get high-capacity HDDs at 10k+ RPM, so if you're limited to 4-8 or so 3.5" bays, you need the big slow ones generally.

Basically, if you will be running a large number of VMs on a small number of 7200 RPM spinners even in a RAID10, you'll need to use some kind of r/w or read caching technology, typically, if your VMs are doing things.

Could be an option to have both. One RAID1 array with SSDs say 2x4TB and one RAID1 with 3.5" HDDs, for example 2x10TB Ultrastar He10. Fast SSD storage for VMs that need that and plenty of slow storage for VMs that need that.

@dave247 said in Question about weather or not I should enable write-through mode on a RAID1 SSD array:

@pete-s said in Question about weather or not I should enable write-through mode on a RAID1 SSD array:

@dave247 All enterprise SSDs have power protection caps so that is an expected feature.

If the raid controller cache makes an improvement or not depends on the workload and the size of the cache.

I think the 3.84TB drives have 4GB cache internally. That's large compared to the RAID controllers cache. What do Dell recommend?

I haven't asked Dell what they recommend. The H730P has 2GB and the H740P has 8GB though.

Give them a call. A little more than 3 years ago I spec'ed a computer with 4 SATA SSDs in two RAID1 arrays and I remember that they were adamant that I get the H730P controller. Machine was an R630.

@dave247 All enterprise SSDs have power protection caps so that is an expected feature.

If the raid controller cache makes an improvement or not depends on the workload and the size of the cache.

I think the 3.84TB drives have 4GB cache internally. That's large compared to the RAID controllers cache. What do Dell recommend?

Thanks, I have to think about this some more.

@scottalanmiller said in Why you don't need a VPN or not?:

@pete-s said in Why you don't need a VPN or not?:

But in a "LANless" environment you expose everything to the internet so your attack surface is huge.

Nothing in LANless design suggests this. You are combining the concept of the architecture of LANless, with the concept of hosted. Of course they go well together, but they are not intrinsically linked or related.

I think you might be associating things that are not really tied together. LAN is a local area network. It doesn't implicate anything about security. It doesn't mean that everything inside the LAN is considered secure and everything outside is hostile. That is not the definition of a LAN. It's just an arbitrary geographical boundary of a network, that used to end when you had a leased line and then it became a WAN.

How the architecture and security in the LAN is setup is a completely separate issue. Modern LAN practice is more network segmentation and inter-zone firewalling and monitoring. That is what I see customer LANs have as well. It's common for instance to have firewalls inside the LAN. Some variation of this is called zero trust network.

Scott, I honestly don't understand what you mean by "LANless" if you don't mean put every client device and every service on the internet directly and use secure communication between everything. Technical speaking LAN-less would be a misnomer if you have more than one device in the same area would it not? Do you have a network diagram describing what LANless is? Sometimes language is not precise enough and besides English is not my first language.

We are getting way OT here but...read it and weep.
http://www.alaskafishradio.com/commercial-fishing-stomps-sport-sector-in-us-economy/

@irj said in What's in your bag?:

@pete-s said in What's in your bag?:

@irj said in What's in your bag?:

One of the best ways to identify a veteran fisherman vs an inexperienced one is by the size of his tackle box. Less is more. The better fisherman I become the less lures I carry. It's the opposite of what most people think..

What do you need other than a laptop to make connector whatever you need to access?

That's pretty funny. Except that a real fisherman has a frickin' boat and nets. Tackle box is for amateurs. :grinning_face_with_smiling_eyes:

Using a net is much easier than fishing lures. With a net, you only need to find fish. Find bait fisherman needs to find and hook the fish. The sport fisherman needs to find, lure and hook in the fish.

While fishing with a net yeilds the most numbers, obviously it doesn't translate to more pay. The highest paid fishermen are sport fishermen. Obviously the sponsored tournament guys are millionaires, but many local guys do quite well. Sport fishing charters often charge $700-1000 a day. We have about 100 of them just in our county. We are a big tourist area, but most areas have 10-20 of those guys in each area around The US. I know of many fishing guides and charters around the world as well.

I understand what you're saying - I have a friend that's really into fly fishing. But sports fishing is still small potatoes to the commercial fishing industry. They make billions.

@matteo-nunziati said in Why you don't need a VPN or not?:

@pete-s firewall os security flaws caused the damage.

If you loose couple thing you reduce probability of attacks that it. Just this.

But in a "LANless" environment you expose everything to the internet so your attack surface is huge. And many systems share the exact same security bugs. It may not take down all servers at the same time though.

To be honest though the end-points are a big problem regardless if you have a LAN or not.

@matteo-nunziati said in Why you don't need a VPN or not?:

I mean: if file were exchanged by https ondemand sessions no propagation was possible.

Yes, I understand. But if the firewall handling the VPN link just allowed http/https you would have the exact same thing.