Learning about servers (hardware)

[myselfolli]

Hey, so I pretty much know my way around consumer grade hardware, but I'm interested in learning more about servers, especially server grade hardware. But I've had problems finding decent places to start, do any of you guys have recommendations?

 

I know that this is a very broad question, but any help would be appreciated!

[Ashley MLP Fangirl]

so you just want to experiment with server stuff? get some kind of old server on the used market. 

 

i would recommend looking for a tower server instead of a rackmount one, because tower servers are most of the time quieter than a rackmount server. 

[myselfolli]

1 minute ago, firelighter487 said:

so you just want to experiment with server stuff? get some kind of old server on the used market. 

 

i would recommend looking for a tower server instead of a rackmount one, because tower servers are most of the time quieter than a rackmount server. 

I have a decently sized basement I could store the servers in, so form factor isn't really a concern for me. But I want to learn about hardware before going ahead and buying some...

[Ashley MLP Fangirl]

2 minutes ago, myselfolli said:

I have a decently sized basement I could store the servers in, so form factor isn't really a concern for me. But I want to learn about hardware before going ahead and buying some...

fundementally they aren't that different from desktops. 

 

if you get into dual-socket systems that's where the fun begins, because then you'll learn what NUMA and UMA are, etc. 

 

but what do you want to know specifically?

[myselfolli]

1 minute ago, firelighter487 said:

fundementally they aren't that different from desktops. 

 

if you get into dual-socket systems that's where the fun begins, because then you'll learn what NUMA and UMA are, etc. 

 

but what do you want to know specifically?

There's nothing specific to what I want to learn, just about server hardware in general. Dual socket systems and the likes

[NelizMastr]

12 minutes ago, myselfolli said:

I have a decently sized basement I could store the servers in, so form factor isn't really a concern for me. But I want to learn about hardware before going ahead and buying some...

The best way to learn is to crack one open and figure out what everything does.

 

Some facts:

 

- Harddisks are 2.5 and 3.5" and usually connected via Serial Attached SCSI (SAS), a standard that's also compatible with SATA. To address all disks backplanes are used; big PCBs with SAS connectors and power connections connected to the drives on one side and to the harddisk controller on the other. This controller can be a RAID controller, which combines disks into arrays to work together for either reliability or performance, but also a HBA, host bus adapter, which only provides the disks to the OS, like on your PC.

 

- Most servers come with IPMI/remote management, HP iLO, Dell iDRAC, Lenovo iMM. This is used for remotely managing the server's display, monitoring information etc. and even to power the server on and off.

 

- Servers use ECC memory that corrects errors as they pass through the memory. This is registered memory that passes through a special register on the memory modules, adding an extra layer of integrity protection. Density of these modules can be high (regular R DIMMs) and very high (LR DIMMs).

 

- Redundancy is important in servers, so lots of components are doubled to make sure a single failure won't take down the server (system board excluded) such as the fans, harddisks (RAID ) and power supplies.

[Ashley MLP Fangirl]

Just now, myselfolli said:

There's nothing specific to what I want to learn, just about server hardware in general. Dual socket systems and the likes

that video will inform you a bit about what NUMA does in dual-socket systems. 

[myselfolli]

3 minutes ago, NelizMastr said:

The best way to learn is to crack one open and figure out what everything does.

 

Some facts:

 

- Harddisks are 2.5 and 3.5" and usually connected via Serial Attached SCSI (SAS), a standard that's also compatible with SATA. To address all disks backplanes are used; big PCBs with SAS connectors and power connections connected to the drives on one side and to the harddisk controller on the other side. This controller can be a RAID controller, which combines disks into arrays to work together for either reliability or performance but also a HBA, host bus adapter, which only provides the disks to the OS, like on your PC.

 

- Most servers come with IPMI/remote management, HP iLO, Dell iDRAC, Lenovo iMM. This is used for remotely managing the server's display, monitoring information etc.

 

- Servers use ECC memory that corrects errors as they pass through the memory. This is registered memory that passes through a special register on the memory modules, adding an extra layer of integrity protection. Density of these modules can be high (regular R DIMMs) and very high (LR DIMMs).

 

- Redundancy is important in servers, so lots of components are doubled to make sure a single failure won't take down the server (system board excluded) such as the fans, harddisks (RAID ) and power supplies.

Thank you for all this information. Where'd you learn about it? Is there a good place for me to start looking online you could recommend?

[Ashley MLP Fangirl]

1 minute ago, myselfolli said:

Is there a good place for me to start looking online you could recommend?

for an old server? ebay or the equivalent of that depending on the country you are in. 

[NelizMastr]

3 minutes ago, myselfolli said:

Thank you for all this information. Where'd you learn about it? Is there a good place for me to start looking online you could recommend?

I went to university, I manage servers for a living hah  

[xentropa]

7 minutes ago, NelizMastr said:

The best way to learn is to crack one open and figure out what everything does.

 

Some facts:

 

- Harddisks are 2.5 and 3.5" and usually connected via Serial Attached SCSI (SAS), a standard that's also compatible with SATA. To address all disks backplanes are used; big PCBs with SAS connectors and power connections connected to the drives on one side and to the harddisk controller on the other. This controller can be a RAID controller, which combines disks into arrays to work together for either reliability or performance, but also a HBA, host bus adapter, which only provides the disks to the OS, like on your PC.

 

- Most servers come with IPMI/remote management, HP iLO, Dell iDRAC, Lenovo iMM. This is used for remotely managing the server's display, monitoring information etc. and even to power the server on and off.

 

- Servers use ECC memory that corrects errors as they pass through the memory. This is registered memory that passes through a special register on the memory modules, adding an extra layer of integrity protection. Density of these modules can be high (regular R DIMMs) and very high (LR DIMMs).

 

- Redundancy is important in servers, so lots of components are doubled to make sure a single failure won't take down the server (system board excluded) such as the fans, harddisks (RAID ) and power supplies.

I don't think registered and ECC are the same thing.

 

You are right that registered memory passes through registers on the controller, though I think this is for improving signal strength particularly when you have a lot if memory > 256GB.

 

ECC uses an extra chip (8 + 1 parity chip) on a a single DIMM to ensure data integrity.

[NelizMastr]

15 minutes ago, xentropa said:

I don't think registered and ECC are the same thing.

They aren't the same thing, they belong together.

 

You have a number of memory types:

 

1. Unbuffered non-ECC - used by all consumer processors

2. Unbuffered ECC - can be used by Ryzen CPUs, Celeron/Pentium/i3 and Xeon E3

3. Registered ECC - used by full server CPUs like Xeon E5/Scalable and Epyc.

 

Quote

You are right that registered memory passes through registers on the controller, though I think this is for improving signal strength particularly when you have a lot if memory > 256GB.

I don't think that's the reason, since there is no need for signal enhancements. All DIMM sockets are wired directly into the CPU and the amount of bandwidth provided is more than enough even for 64 or 128GB LRDIMMs. In fact, if that register was only for high density memory, there wouldn't be low capacity registered modules. On DDR3 you can go as low as 1GB.

 

Quote

ECC uses an extra chip (8 + 1 parity chip) on a a single DIMM to ensure data integrity.

Correct, but this isn't an in-depth explanation for many reasons. OP is at Servers 101, no need to go super deep yet.