Not True-HBA Passthrough

[Wallace Barrow]

Hey All, 

I have a question on what FreeBSD is doing with these RAID cards or actually what the RAID card is really doing. 

My initial guess is the RAID card is still inserting itself into the kernel to present the drives. 

Current situation:

I have a server with a PERC H730P Mini (Embedded) card installed. From the Dell website it says it can do pass-through (no-raid)

1. The card is currently in HBA personality mode, hard drive caching on the card is turned off and inside the card bios you can set the disk to JBOD non RAID mode.

2. Installed FreeBSD 11.3 on the two SSD's in a mirror using ZFS.

3. When in the OS looking at /dev/ after the install I see this.

lrwxr-xr-x   1 root  wheel        4 Aug 23 19:25 megaraid_sas_ioctl_node -> mfi0
crw-r-----   1 root  operator  0x53 Aug 23 19:25 mfi0
crw-r-----   1 root  operator  0x6c Aug 23 19:25 mfisyspd0
crw-r-----   1 root  operator  0x6d Aug 23 19:25 mfisyspd0p1
crw-r-----   1 root  operator  0x6e Aug 23 19:25 mfisyspd0p2
crw-r-----   1 root  operator  0x70 Aug 23 19:25 mfisyspd0p3
crw-r-----   1 root  operator  0x74 Aug 23 19:25 mfisyspd1
crw-r-----   1 root  operator  0x75 Aug 23 19:25 mfisyspd1p1
crw-r-----   1 root  operator  0x76 Aug 23 19:25 mfisyspd1p2
crw-r-----   1 root  operator  0x77 Aug 23 19:25 mfisyspd1p3'

Then my pool is using the the partitions listed above for boot, swap, zfs, etc.

gpart show
=>        40  3125627488  mfisyspd0  GPT  (1.5T)
          40        1024          1  freebsd-boot  (512K)
        1064         984             - free -  (492K)
        2048    20971520          2  freebsd-swap  (10G)
    20973568  3104653312          3  freebsd-zfs  (1.4T)
  3125626880         648             - free -  (324K)

=>        40  3125627488  mfisyspd1  GPT  (1.5T)
          40        1024          1  freebsd-boot  (512K)
        1064         984             - free -  (492K)
        2048    20971520          2  freebsd-swap  (10G)
    20973568  3104653312          3  freebsd-zfs  (1.4T)
  3125626880         648             - free -  (324K)

Normally when I use ZFS I make sure I have a real HBA card and when I look at /dev/ and all my disks they are presented to me in a way I am used to seeing. 

Can I still use ZFS in this setup? May not be a straight forward answer but I just want to learn what is happening.

Is the megaraid_sas_ioctl_node link just another way to present the drives to the OS?  The server has been stable for a week or so with no checksum or ZFS errors since installing.

I have another server with a UCSC-RAID-M5HD card in it. From the Cisco site it says to can do pass-through. I get the same results above when this UCSC-RAID-M5HD card is in JBOD personality mode and disks in JBOD mode. 

Thank you!

-- 
  Wallace Barrow
  incin at incin.me