PowerEdge 1900 - Need more SAS Drives - to increase disk space on server

Question

Hi-

I'm new to these forums.

Wanted to know if I am shopping for the correct hardware - example a daughter or expansion card or controller - in order to install 4 drives in server.

According to the manual for our server:

http://support.dell.com/support/edocs/systems/pe1900/en/hom/pdf/hom.pdf

Per the doc above - if we want up to 4 - SAS drives in our server -we'll need an expansion/daughter card(SAS Controller) - correct?

"The optional SAS controller card supporting up to four SAS or SATA drives in a RAID configuration
and illustrated in Figure 3-13 should only be installed into slot 4 (PCIE_X4_4). The optional integrated SAS
RAID controller daughter card illustrated in Figure 3-14 should only be installed into the integrated daughter
card slot (INT_STORAGE) on the system board. See Figure 6-2 for the locations of these connectors."

I assume we need another SAS controller to get up to 4 drives - if so, these are the supported cards for the 1900:

<ADMIN NOTE: Broken link has been removed from this post by Dell>

Two SAS cards supported for Dell 1900:

SAS 5/E Adapter(XM768) -> Dual channel - can add 4 more drives - correct?

SAS 5/iR Adapter(MG129) -> single Channel can add 2 more drives - correct?

NOTE:

We currently have 1 TB - SAS drives in the machines with a RAID 1striping) configuration.

Thanks or any help.

-P

theflash1932 · Accepted Answer

2TB drives are supported on the PERC 5, although I can't say for sure on the SAS 5.

theflash1932 · Accepted Answer

If you have SATA drives, that changes everything. Yes, you can connect two more drives to the onboard SATA ports and do whatever you want with them (I'm assuming then that the OS is managing the RAID 1 for the first two drives - it can do the same for the second set). For this you would only need regular SATA cables to connect the drives to the SATA ports.

Because you only have 4 onboard SATA ports (I see no documentation of any 1900 variant having more than 4), you can only use 4 drives. If you need to use 6, then you will need a controller for the two extra drives that do not have available connectors on the motherboard. For this controller, you can get the SAS 5/iR; if you ever plan on rebuilding/repurposing this server, consider getting the PERC 5/i, as it is a much more robust, peformance-oriented controller.

theflash1932 · Answer

The SAS 5/iR supports 4 drives with a single connector on the RAID controller split off to 4 SAS/SATA connectors.

The PERC 5/i supports 8 drives with each of two connectors on the RAID controller supporting 4 drives as described above.

Both controllers are capable of supporting more than 4 drives given the correct hardware.

theflash1932 · Answer

The SAS 5/E is an (E)xternal SAS RAID controller, so will not work to add drives internal to the system.

The SAS 5/iR is an (I)nternal SAS RAID controller, certified for use in a 1900 for internal storage.

The 1900 also supports the PERC 5/i, which is an (I)nternal SAS RAID controller with more features and better performance than the SAS 5/iR.

If you currently have SAS drives in your system, they are already connected to a SAS or RAID controller. How are they connected? And what are they connected to?

Daniel My · Answer

Hello Spichelman

I doubt you need any additional equipment to add more drives. The PE1900 supports up to 6 HDD's. The only reason you would be limited to 2 HDD's is if you did not purchase the server with a controller.

If the server was purchased with a controller then it will support 6 drives. You do not need multiple controllers. If you did not purchase a controller with the server then you would want to get either a PERC 5/i or SAS 5/iR.

Thanks

theflash1932 · Answer

No, since you have SAS drives already in your system, you don't need another controller, but you may need a different cable.  Just because the system will hold 6 drives, doesn't mean you can automatically use them all.  Assuming the drives are cabled to the controller, you likely have a 4-drop cable going from the single channel on the SAS 5 controller to two drives, with two connectors still available for more drives.  HOWEVER, I have seen ship from Dell, systems with a 2-drop cable, where only two drives could be connected to the single channel of the controller.  If you have a 2-drop cable, you will need to get a 4-drop cable to use more drives.  If you do have a 4-drop cable, then only 4 drives can be used.  The SAS 5 only has a single connector, so without a special expander, you can only use 4 drives.  If you have a PERC 5, it has two channels, each of which can support 4 drives, but at the very least, you would need a second cable to be able to use more than 4 (assuming you have a 4-drop cable and not a 2-drop cable).

spichelman · Answer

Hi, I thought we were using the on-board controller? That supports 6 drives? Not according to the manual. No - we did not purchase a separate controller. -P

theflash1932 · Answer

There are only 4 ports on the motherboard and they are SATA ports, so if you have SAS drives, they have to be connected to a controller card.  Both the SAS 5 and the PERC 5 are listed as 'integrated' controllers, even though they are cards; they are called integrated because they are specifically designed to go in a dedicated slot in that server.

spichelman · Answer

We have 2 - 1 TB SATA drives.

I was told by Dell Support that we should use the PERC5 or SAS5ir.

So - you are saying we can use two more drives in our current onboard config - if we have the right cable?

We'd like to use 6 drives - and you are saying we still would not need a new PCI-X installed controller as I mentioned above?

Thanks again for your feedback.

-P

spichelman · Answer

Excellent - that makes more sense now.

However - sounds as if we can only use 1TB - SATA drives w/ those controllers - not any larger per Dell.

They would not give me the details, doc or HCL for the PERC5/i or SAS 5/ir.

So - we could see what controllers supported what drives...anyway.

We'll want more than 4 drives since we can only use 1TB drives but will not be re-purposing - this is a production machine that we'll only want to add space/drives to the Linux machine - RHEL5.7 - RAID1 - using ext3/LVM.

Any other thoughts?

Again - I appreciate the great detail.

Thx,

-P

spichelman · Answer

Thx again for your help! We'll probably get the PERC5/i - thanks to you! Take care. -P

PowerEdge HDD/SCSI/RAID

PowerEdge 1900 - Need more SAS Drives - to increase disk space on server

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