maximum number of disks ?

[nulik]

Hi,
I would like to know how many disks do current motherboards support?
I am building a server and I need to mount about 200 Terabytes or more if possible. What is the maximum for SATA drives? Any cheap PCI card you would recommend to extend motherboard's limit?

Thanks in advance

 

[RGone]

You really need a server type motherboard that supports Controller Type:Serial Attached SCSI (SAS), that way you can use large expansion backplanes to get those Terabytes. Tyan motherboard company makes such boards for one such company.

 

[Realee]

Someone poke Thiddy. He'll have 100 different options here.

You're going to need a RAID card and SATA expanders to get that kind of storage. Can't give you more than that myself though.

 

[txus.palacios]

Yes, someone, summon Thiddy.

You'll need SAS RAID cards, and extenders. I mean, you need like... 50HD? (if you plan to use Hitachi's 4TB HDDs, or 100HDs if you plan to use plain 2TB HDDs)

 

[nulik]

thanks guys. but I am looking to build the storage server on commodity PCs. Server hardware will cost a lot. I found current mobos support 8 SATAs. this would give me 32TB of storage with 4TB disks.
But, could I use USB ports to connect SATA drives?
I found this adapter at only 5 bucks:
Eforcity 245340 USB 2.0 to IDE SATA HDD Converter Cable
it says it can connect SATA to USB, so if the USB port can handle 128 devices I can easily build a huge storage server at a very low cost.
What do you think?

 

[Neuromancer]

USB is not a good option for storage as it cant be written and read at the same time. IIRC.

A RAID card does not have to cost a lot. the more expensive models just add expandable cache better processors (performance) and maybe BBU, not more ports.

So using a 2 port SAS card with expanders will be your cheapest option. Not that performance will suck as you will be limited to about 2.4GBps. (Sounds fast but not for 100+ drives lol)

EDIT: Guessing you will need at least 150 drives for raid 5 or 200 for raid1

Are you going to be running windows server or linux?

 

[nulik]

I found this awesome article on building petabyte storage systems

http://blog.backblaze.com/2009/09/01/petabytes-on-a-budget-how-to-build-cheap-cloud-storage/

 

[nulik]

Are you going to be running windows server or linux?

linux!
Thanks a lot, I will check on SAS

 

[txus.palacios]

I found this awesome article on building petabyte storage systems

http://blog.backblaze.com/2009/09/01/petabytes-on-a-budget-how-to-build-cheap-cloud-storage/

I'll send thideras a PM.

IIRC, thideras was also thinking on making something like this?

 

[Automata]

Sorry for the being late to the thread. If this is a server for a production environment and/or is "mission critical" (i.e. for a business), using desktop hardware is a cheap and reckless way to get storage. The hardware isn't as high of quality and you are bound to run into problems with those sized arrays. This would be a much better option for a SAN. I don't have experience with SAN equipment and would not be able to give much more advice.

--------

If this is for personal use, you will probably want to get a RAID card (or HBA if you want to do software RAID) and use a SAS expander(s). The limiting factor in the number of drives you can run will be the case. You can run the RAID card and SAS expander on normal desktop hardware, which is actually what I'm doing in my file server right now. Specifically, I'm using a LSI 8708EM2 RAID card with the HP SAS expander. The case is a Norco 4020, which can house 21 hard drives without modification. I currently have 25 TB of raw spinning disk, split into two arrays (one with seven 1tb disks, and the other with nine 2tb disks).

The RAID card you choose isn't a big factor, except you will want to make sure it has the proper connectors (8087) and can work with "advanced format" hard drives (i.e. 4kb sectors).

Here is a link to the HP SAS expander. http://www.storageforum.net/forum/showthread.php?t=8012

So, you could technically run 28 hard drives for every 8087 connector the card has. Again, the limitation comes down to storing the hard drives, rather than driving them. Theoretically speaking, you could run hundreds of drives off a single system. If you had a ton of money to drop, you could buy a bunch of rackmounted cases that can store a lot of drives and simply use external SAS (8088) connectors to the back of each case, which would drive a SAS expander and the drives.

With more details about the project, I think we could make better suggestions. Specifically, what this is for, what you expect of it, minimum requirements, etc. You seem to know most of these answers, already.

 

[nulik]

Here is a link to the HP SAS expander. http://www.storageforum.net/forum/showthread.php?t=8012
.

thanks thideras, It is a great card this expander. The server is for business, it is going to run a database with high availability and replication. So, if one server , or disk in one server fails there will be always another box available, this is why we can use commodity PCs.