Perc H700 (LSI SAS 2108) possible to support Raid-1 and passthrough ?

[TedB]

Hi,

I have Perc H700 which supposedly is based on LSI SAS 2108 chipset.

I would like to cross flash it to be able to create a RAID-1 on two attached disks and rest of attached disks just to passthrough as in a dumb controller straight to OS.

This would allow me to install OS on the RAID-1 (MS Windows) and create storage spaces on rest of the disks without the performance hit of the raid controller.

Previously I have tried to configure two disks as RAID-1 and rest of them as individual RAID-0, however the performance is very poor compared to LSI SAS 2008 in IT mode (passthrough).

An article on STH site suggests that LSI SAS 2108 supports HBA mode with following functionality: RAID 0, RAID 1, RAID 1E, RAID 10 and Passthrough (non-RAID).

LSI SAS 2108 RAID Controller Information and Listing

Which firmware should I use in order to achieve this ?

 

[vanfawx]

Should be able to. You enable JBOD mode on the card and then set specific drives as JBOD. We do this frequently on dell H310's which are LSI 2008 in IR mode. I'm not sure the H700 supports JBOD mode however based on a quick google. You can check this easily via MegaCli:

MegaCli AdpGetProp enablejbod -aALL

If you get this response:

Adapter 0: JBOD: Enabled

Then you are fine to mark drives as JBOD via the following:

MegaCli PDMakeJBOD -PhysDrv[32:5] -a0

Replace [32:5] with the proper backplane and drive ID's. If it works you should get the following response:

Adapter: 0: EnclId-32 SlotId-5 state changed to JBOD.

Which you should see the drive pass through to the OS after this.

Hope that helps!

 

[TedB]

Unfortunately Dell Perc H700 (LSI SAS 2108) doesn't allow JBOD and it doesn't simply passthrough drives like in Dell H310 (LSI SAS 2008) mentioned by @vanfawx

# ./MegaCli -AdpGetProp EnableJBOD -a0

Adapter 0: JBOD: Disabled

Exit Code: 0x00

 

[Terry Kennedy]

Unfortunately Dell Perc H700 (LSI SAS 2108) doesn't allow JBOD and it doesn't simply passthrough drives like in Dell H310 (LSI SAS 2008) mentioned by @vanfawx

It depends on the operating system. In FreeBSD, you can set the sysctl hw.mfi.allow_cam_disk_passthrough to non-zero and unconfigured disks on the H700 will show up as da devices (configured volumes will still show up as mfid devices). This is generally considered a Bad Idea, though, since the controller doesn't keep track of what the host OS writes on those drives and may report them as "unconfigured good" or "foreign". A "helpful" person might see that during boot and "fix" it for you, corrupting some data written to the drives.

 

[BLinux]

Unfortunately Dell Perc H700 (LSI SAS 2108) doesn't allow JBOD and it doesn't simply passthrough drives like in Dell H310 (LSI SAS 2008) mentioned by @vanfawx

# ./MegaCli -AdpGetProp EnableJBOD -a0

Adapter 0: JBOD: Disabled

Exit Code: 0x00

Can't you just enable it? :

MegaCli64 -AdpSetProp EnableJBOD 1 -a0

 

[nthu9280]

IIRC, I tried that couple of years ago but didn't update the controller for some reason. It could have been PICNIC (Problem in chair not in computer) though.
There is an option to export settings to INI file and the file still showed jbod enabled = false.



Sent from my Nexus 6 using Tapatalk

 

[RomanShein]

Can't you just enable it? :

MegaCli64 -AdpSetProp EnableJBOD 1 -a0

- Thanx, worked like a charm. Instantly I've got the option "Make JBOD" for an unconfigured drive.

 

[batot]

Can't you just enable it? :

MegaCli64 -AdpSetProp EnableJBOD 1 -a0

Can't becouse get answer JBOD not supported. LSI SAS 2108 don't have JBOD ! Amen.