Hi Mac'ers,
I have just been testing with Areca 1882i Internal RAID card and MaxConnect BackPlane (from MaxUpgrades: www.maxupgrades.com) with latest HGST Ultrastar He8 12Gb/sec SAS disk.
For those who are not aware the MaxConnect backplane is a rather ingenious way to get around the performance and disk size limit of Mac Pro.
The MaxConnect has special trays into which you install your shiny new faster and bigger disks, in place of standard Mac Pro sled. They then take the power from the inbuilt SATA/SAS slots and use a set of mini SAS to 4 SATA/SAS serial cables to provide the data path. These are then terminated on internal SAS/SATA connector of PCIe RAID card (in my case this is an Areca ARC-1882i).
In my setup I had 4 x 4TB 6Gb/sec SATA drives with 3 set up as RAID 5 and the 4th having a replicated backup. However with 3 x 4TB S disk resulting in total 8TB storage I have gotten past 4TB limit of my 4th 4TB SATA backup disk and so decided to upgrade this to 6TB HGST He8 12Gb/sec SAS drive.
I went for SAS rather than SATA as this provides 12Gb/sec while SATA is only 6Gb/sec and I also decided to upgrade the ARC-1882 to an ARC-1883 series card which has 12Gb/sec support.
I expected do the upgrade by:
1. Remove 4TB back up disk and replace by 6TB disk
2. Carbon Copy Clone RAID 5 contents (3 x 4TB Disks) to the single 6TB disk
3. Remove ARC-1882i and replace with ARC-1883lp
4. Reconnect all drives to ARC-1883lp
4. Reboot computer from single 6TB disk
5. Regenerate (if required...) RAID 5 on ARC-1883lp
6. Carbon Copy Clone 6TB contents over to RAID 5 (3 x 4TB Disks)
This a quite a few steps and leaves you vulnerable to single disk failure, so I also did Time Machine backup to main Xserve back up server.
Here is how far I got...
Step 1. Replace 4TB back up disk with 6TB He8 SAS disk.
Disk is not visible via management interface...
Step 1.1.
Contact Areca support as determine if there was a know compatibility problem with He8 (which are 4096 sector drives) and 1882.
They advised to upgrade the 1882 to latest firmware, which I did via the provided cli64 interface.
Step 1.2.
NOTE: I could not get the firmware upgrade to work using the HTML UI interface, but cli64 interface worked a charm. The upgrade requires that you load 3 separate files.
Rebooted after upgrade and still cannot see He8 SAS drive within Areca management interface
Step 1.3.
Recontact Areca support, they cryptically advise that there might be a problem with some "legacy" SATA backplanes and 12Gb/sec SAS backplanes, which results in failure to power up drive...
Step 1.4.
Download the HGST 4TB SATA disk specifications and the 6TB He8 SAS disk specifications and look at all the Pin Out details.
Ahhh it appears that 12Gb/sec SAS has taken over "Pin 3" power for a "Power Disable" function which provides the equivalent of a hard reset capability, while on SATA this was used to provide a vendor specific function for circuit "Pre-Charging".
So answer appears to be that I need to do some physical surgery to stop power "Pin 3" from getting any voltage.
With the "MaxConnect" backplane I could achieve this by cutting one of the internal transfer wires, but reading the HGST He8 manual it also says that power pins P1, P2 & P3 are all internally tired. So this would mean cutting all three transfer wires.
Given that it was only speculative that Pin 3 was the cause of the problem, I was not too keen to start chopping up the MaxConnect backplane, so needed an alternate.
Step 1.5.
Simple solution put masking tape across power pins P1, P2 & P3 on MaxConnect connector. This would then isolate these and provide equivalent of cutting but be reversible in the event that Pin 3 was not the problem.
Step 1.6.
With masking tape positioned across P1, P2 & P3 reboot machine.
Ok!! He8 SAS now visible within Areca management interface, so configure it as pass-through disk and it appears as an un-initialised disk on Mac Pro.
Summary: 12Gb/sec SAS Pin 3 could results in compatibility problems with Mac Pro internal disk SATA power. For HGST He8 SAS ensure that you have no power coming on P1, P2 & P3.
I am now waiting for 1883 to arrive before I complete steps 3 - 6 .
I will provide a performance update on impact of ARC-1883 vs ARC-1882 once complete.
Cheers,
Zebity
(Mac Pro with 2 x 3.46GHz, Small Tree 10Gbe, Areca 1882/3 & Nvidia Titan)
I have just been testing with Areca 1882i Internal RAID card and MaxConnect BackPlane (from MaxUpgrades: www.maxupgrades.com) with latest HGST Ultrastar He8 12Gb/sec SAS disk.
For those who are not aware the MaxConnect backplane is a rather ingenious way to get around the performance and disk size limit of Mac Pro.
The MaxConnect has special trays into which you install your shiny new faster and bigger disks, in place of standard Mac Pro sled. They then take the power from the inbuilt SATA/SAS slots and use a set of mini SAS to 4 SATA/SAS serial cables to provide the data path. These are then terminated on internal SAS/SATA connector of PCIe RAID card (in my case this is an Areca ARC-1882i).
In my setup I had 4 x 4TB 6Gb/sec SATA drives with 3 set up as RAID 5 and the 4th having a replicated backup. However with 3 x 4TB S disk resulting in total 8TB storage I have gotten past 4TB limit of my 4th 4TB SATA backup disk and so decided to upgrade this to 6TB HGST He8 12Gb/sec SAS drive.
I went for SAS rather than SATA as this provides 12Gb/sec while SATA is only 6Gb/sec and I also decided to upgrade the ARC-1882 to an ARC-1883 series card which has 12Gb/sec support.
I expected do the upgrade by:
1. Remove 4TB back up disk and replace by 6TB disk
2. Carbon Copy Clone RAID 5 contents (3 x 4TB Disks) to the single 6TB disk
3. Remove ARC-1882i and replace with ARC-1883lp
4. Reconnect all drives to ARC-1883lp
4. Reboot computer from single 6TB disk
5. Regenerate (if required...) RAID 5 on ARC-1883lp
6. Carbon Copy Clone 6TB contents over to RAID 5 (3 x 4TB Disks)
This a quite a few steps and leaves you vulnerable to single disk failure, so I also did Time Machine backup to main Xserve back up server.
Here is how far I got...
Step 1. Replace 4TB back up disk with 6TB He8 SAS disk.
Disk is not visible via management interface...
Step 1.1.
Contact Areca support as determine if there was a know compatibility problem with He8 (which are 4096 sector drives) and 1882.
They advised to upgrade the 1882 to latest firmware, which I did via the provided cli64 interface.
Step 1.2.
NOTE: I could not get the firmware upgrade to work using the HTML UI interface, but cli64 interface worked a charm. The upgrade requires that you load 3 separate files.
Rebooted after upgrade and still cannot see He8 SAS drive within Areca management interface
Step 1.3.
Recontact Areca support, they cryptically advise that there might be a problem with some "legacy" SATA backplanes and 12Gb/sec SAS backplanes, which results in failure to power up drive...
Step 1.4.
Download the HGST 4TB SATA disk specifications and the 6TB He8 SAS disk specifications and look at all the Pin Out details.
Ahhh it appears that 12Gb/sec SAS has taken over "Pin 3" power for a "Power Disable" function which provides the equivalent of a hard reset capability, while on SATA this was used to provide a vendor specific function for circuit "Pre-Charging".
So answer appears to be that I need to do some physical surgery to stop power "Pin 3" from getting any voltage.
With the "MaxConnect" backplane I could achieve this by cutting one of the internal transfer wires, but reading the HGST He8 manual it also says that power pins P1, P2 & P3 are all internally tired. So this would mean cutting all three transfer wires.
Given that it was only speculative that Pin 3 was the cause of the problem, I was not too keen to start chopping up the MaxConnect backplane, so needed an alternate.
Step 1.5.
Simple solution put masking tape across power pins P1, P2 & P3 on MaxConnect connector. This would then isolate these and provide equivalent of cutting but be reversible in the event that Pin 3 was not the problem.
Step 1.6.
With masking tape positioned across P1, P2 & P3 reboot machine.
Ok!! He8 SAS now visible within Areca management interface, so configure it as pass-through disk and it appears as an un-initialised disk on Mac Pro.
Summary: 12Gb/sec SAS Pin 3 could results in compatibility problems with Mac Pro internal disk SATA power. For HGST He8 SAS ensure that you have no power coming on P1, P2 & P3.
I am now waiting for 1883 to arrive before I complete steps 3 - 6 .
I will provide a performance update on impact of ARC-1883 vs ARC-1882 once complete.
Cheers,
Zebity
(Mac Pro with 2 x 3.46GHz, Small Tree 10Gbe, Areca 1882/3 & Nvidia Titan)
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