The newer versions of mdadm since a few years ago recognize arrays by the metadata on the block devices and no longer rely on device names, so if the disks order and names change, the array is recognized automatically. ZFS on the other hand depends on the devices' names, which can be either:
/dev/disk/by-id
/dev/disk/by-label # not available for ZFS component disks
/dev/disk/by-partuuid
/dev/disk/by-path
/dev/disk/by-uuid # not available for ZFS component disks
The immutable ones are /dev/disk/by-id/wwn-* and /dev/disk/by-partuuid. But there are problems:
under /dev/disk/by-id, only the names starting with wwn- are immutable, but not all sata storage devices provide these names.
the UUIDs under /dev/disk/by-partuuid belong to the partitions themselves and not to the filesystems within them, according to the theory, yet mkfs may change these UUIDs upon formatting. It's a caveat.
@host_c said: Need some details to this, or I might not understood something?
Nah, in that part I mean that if Shakib successfully install proxmox with ZFS (never tried proxmox) then it seems that Proxmox installation process offering us ZFS-raid during setup. So my advice was:
1. Install Proxmox on baremetal.
2. Spin-up VM with maxed resources minus ZFS RAM (for example, if our server 128G and 2x4TB NVME, then leave 8GB/10GB RAM for host and rest 119GB for VM).
3. And inside that VM install cPanel/DA and sell shared hosting.
So we successfully completed task "shared hosting server on ZFS raid".
Comments
The newer versions of mdadm since a few years ago recognize arrays by the metadata on the block devices and no longer rely on device names, so if the disks order and names change, the array is recognized automatically. ZFS on the other hand depends on the devices' names, which can be either:
The immutable ones are
/dev/disk/by-id/wwn-*
and/dev/disk/by-partuuid
. But there are problems:/dev/disk/by-id
, only the names starting withwwn-
are immutable, but not all sata storage devices provide these names./dev/disk/by-partuuid
belong to the partitions themselves and not to the filesystems within them, according to the theory, yetmkfs
may change these UUIDs upon formatting. It's a caveat.THX @davide
I was not up to date on MDADM.
Host-C - VPS Services Provider - AS211462
"If there is no struggle there is no progress"
This setup will work perfectly.
HostCram LLC - Web Hosting Built For Speed, Reliability, Security & Uptime! [We operate AS39618]
@HostMayo
as a side-note, since we dived into storage.
Here is a comparison between storage technologies and general use case scenario with general strengths and weaknesses:
Host-C - VPS Services Provider - AS211462
"If there is no struggle there is no progress"
NFS, iSCSI, iSCSI over Fiber Channel are storage transport protocols, they "share" the raid type you have on the server/storage.
I included them in the comparison above just to have an idea on performance/cost factors.
Host-C - VPS Services Provider - AS211462
"If there is no struggle there is no progress"