Exist any incompatibility between an existing virtual drive created on LSI MegaRAID 9240-4i SAS/SATA Controller with RAID1 and the ZFS filesystem?
I tried to make mirror(2xSATA HDD 300Gb) on freebsd 10.1 release but don’t worked. Detected controller, drives, virtual drive mfid0 but when to choose filesystem(I chosed ZFS) asked me for type of RAID and I selected RAID1 but it won’t let me go further saying that “…must have 2 or more hdd”. From to buttons and only “Cancel” was active.
If you have set RAID1 from WebBIOS of the RAID controller, can you make again from OS a software RAID1 again?
Answer
Two disks hardware raided into a raid1 will present a single disk to the OS, in this case mfid0 as you noticed. That single disk can’t then be made into a raid1 on a software level. If you would’ve had four physical disks to begin with, it would be possible but quite silly.
Chose either all hardware raid or all software raid.
If you go for the hardware raid option and want ZFS for its other features such as compression for instance, simply add the logical disks as stripes. This is something beyond the scope of the installer and will have to be done using the CLI.
zpool create zfs mfid0 [mfid1] [...]
Error correction won’t work in this case as you don’t have any redundancy from ZFS’ perspective. Setting the option copies=2to a ZFS filesystem will overcome this with the caveat that it takes twice as much space to store files.
Attribution
Source : Link , Question Author : S3th76 , Answer Author : stralle
