Data Server or Honking Big LTSP server??

[richinsc]

I am going to be build a data storage system and LTSP server. But I am debating on keeping them separate systems or have them be the same system.

Of the advantages I thought of to keep them separate is the fact that I would be able to use the disk system with other servers and services mounting what disk that they need without compromising security. However when serving up data to LTSP clients the network becomes the bottleneck so it might be better to have the LTSP use the data array all on its own.

I comparison with other data storage systems here, mine would be quite small to start (12TB). Any thoughts on what you would do?

For my LTSP system I am going to be using a motherboard that has four CPU slots and if I can find one that will allow for the new 6 core CPU's then I will use them giving me a total of 24 cores. Memory would be somewhere in the range of 128GB.

If I end up separating the Systems I would have any servers I need to connect to the storage system to connect via Fibre.

 

[richinsc]

I am thinking about building a central NAS and then export the storage via Fibre Channel to the server I need them to including the LTSP system. The LTSP system just needs to be able to serve the home directions that would be on the filer. I have decided to to with openfiler instead of freenas. But no instead of a 10TB LTSP I am going to build a 50TB NAS I guess.

Since Tape Backup and DVD Backup are too expensive in terms of how often the media needs to be changed to keep it good, I will likely just end up building a second 50TB Bacula Server that I can pic and choose what to back up and what not to backup.

I keep going back and forth on hardware and software raid. And a question for anyone who knows this, but for commerical vendors such as netapp do they use hardware raid at disk level but then utilize software partitioning for the creation of storage volumes or is everything software raid.

for my backup server I know that I would use hardware raid and have all the disks in a RAID6 configuration and then make the volume one big 50TB Volume and then just backup to that. I wouldn't do that to my NAS. But I wonder if fragmentation would cause issues should I ever need to restore with the backup server having a volume that large.

Now I just have to figure out how many CPU's and how much memory to use for the filer/NAS box.

Oh boy is this going to get expensive in a hurry.. Already saw that cases are going to cost 1000 a piece.

 

[outspoken]

how many users for LTSP? is all traffic going to be LAN or will some be WAN? What connection speeds will the users have going back to the LTSP server?

Was there any particular reason you wanted to go with Fibre instead of iSCSI?

 

[richinsc]

All traffic will be on LAN and Connections from the terminals to the LTSP will be 10/100. I'm just wanting to make sure that data serving is on the LTSP server itself is quick since all the action will happen on the LTSP server it doesn't matter that the clients terminals won't be fast, they will only be having there terminals for screen sessions.

The LTSP server specs I am still looking into. I just need to make sure then since I will be using a central filer and it will be shared with other servers (web, database, file-server, ltsp) I think the specs on the NAS should be top-end. I was thinking Quad Quad-Core but then that may be overkill. I was thinking about doing the same Quad Quad-core for the LTSP to future proof it but don't know if I will. I'll see..

Reason for Fibre is speed. Wanted to have the 4Gb/s that is standard in FC instead of bonding 4 1GB/s links to achieve the same result. Plus if I get emulex cards with dual FC I could have 8GB/s between filer and server(s).

 

[outspoken]

All traffic will be on LAN and Connections from the terminals to the LTSP will be 10/100 .... it doesn't matter that the clients terminals won't be fast

not always the case so I had to ask. I've setup large LTSP environments before with full desktop use and client/network does matter.

I was thinking about doing the same Quad Quad-core for the LTSP

two quads will be enough to handle just about anything, but you still haven't specified the user count in the environment.

Reason for Fibre is speed. Wanted to have the 4Gb/s that is standard in FC instead of bonding 4 1GB/s links to achieve the same result. Plus if I get emulex cards with dual FC I could have 8GB/s between filer and server(s).

speeds are associated with different types of FC, there is no "standard speed" for the overall technology. why not go infiband if you're really concerned about speed? kidding.

 

[Duck]

I keep going back and forth on hardware and software raid. And a question for anyone who knows this, but for commerical vendors such as netapp do they use hardware raid at disk level but then utilize software partitioning for the creation of storage volumes or is everything software raid.

I see this question come up often and the question really shouldn't be does "does vendor A use hardware or software RAID?" the question should be "why do i care?"

At the base level all RAID is software, the only difference is whether or not that software is embedded in a customized ASIC designed specifically to handle those instructions or running on a general purpose processor.

Obviously the customized ASIC will result in more efficient operations but if I'm a vendor and choose instead to use a general purpose processor but give it enough power to handle the unoptimized instructions the end result to the user is the same.

As an end user your only concern should be do I get x amount of performance with my required features for y amount of money.

To my knowledge NetApp does everything in a highly customized software stack on general purpose processors.

Disclaimer: I currently work for NetApp

 

[richinsc]

In the planning stages of building my own NAS/SAN system I have recently read about the use of sas expander to expand the amount of storage available on one system. After finding that with sas expanders you can use sas/sata disk I was quite pleased with that little info. My question however comes to RAID controllers, is there any tips on looking for RAID Controllers that a compitble with SAS Expanders other then making sure it is SAS/SATA Compatible?

I am just want to future proof anything I build to ensure that I don't have to rebuild or build an second system later on. Plus since many SAS Controllers can handle up to 128 devices. I think that should more then cover my needs in terms of future proofing, especially if I used 2TB SATA Disks.

128 2TB Disks is roughly 262 TB. More then I will ever need but it would be nice to be able to expand to that should I need it using SAS Expanders.

 

[outspoken]

In the planning stages of building my own NAS/SAN system I have recently read about the use of sas expander to expand the amount of storage available on one system. After finding that with sas expanders you can use sas/sata disk I was quite pleased with that little info. My question however comes to RAID controllers, is there any tips on looking for RAID Controllers that a compitble with SAS Expanders other then making sure it is SAS/SATA Compatible?

I am just want to future proof anything I build to ensure that I don't have to rebuild or build an second system later on. Plus since many SAS Controllers can handle up to 128 devices. I think that should more then cover my needs in terms of future proofing, especially if I used 2TB SATA Disks.

128 2TB Disks is roughly 262 TB. More then I will ever need but it would be nice to be able to expand to that should I need it using SAS Expanders.

apologies, but it sounds like you're going outside the necessary scope of this project.

if you're needs will potentially require 200+ TB then start looking at commercial appliances now and don't waste money. EMC/NetApp/etc.

 

[richinsc]

That is true. I guess if I ever reach that point then I will likely do that. Currently will only require storage for 30 ppl, And just want to make sure I am planning for ability to expand easily. Will likely start out at 12 TB and then expand when needed.

I didn't say I would need more the 200 TB. I just was saying that it would be nice to have the system be easily expandable. Especially if ever start pushing the 50TB range. Thus my question in reguards to Raid Controller/ SAS Expander compatibility.