RAID hardware vs RAID software

[xigloo]

hello people, i've a doubth; I've a DELL server Poweredge, with 2 hdd sata in RAID1 hardware by internal controller . For good performance , i must install proxmox 6.4 on disk RAID1 disk selecting ZFS RAID0 , or better erase RAID1 hardware and install proxmox in ZFS RAID1 on these 2 free disks ? Or create 2 RAID 0 hardware and than install proxmox in ZFS RAID1 on it?

thanks , have a good weekend :]

 

[Dunuin]

Never combine HW raid with ZFS or you might get corrupted data. Use HW raid with LVM thin instead. Or connect the drives to a HBA or non-raid onboard ports and let ZFS do SW raid if you care abount your data integrety (bit rot protection and so on).

 

[xigloo]

Never combine HW raid with ZFS or you might get corrupted data. Use HW raid with LVM thin instead. Or connect the drives to a HBA or non-raid onboard ports and let ZFS do SW raid if you care abount your data integrety (bit rot protection and so on).

i've understood... :[
i'm sad because i've already a server configured in this way ( HW raid and ZFS proxmox ) and, before make another, i had this doubt. So, you recomand me reformat this server without hw raid, and restore vm on new zfs proxmox installation? apparently, the system seems is work well ( VM with win 2019 server ) ....

 

[Dunuin]

Here is the official ZFS documentation on HW raid and why its a bad idea to use it. So yeah, I would do a fresh install. Isn't that hard if you backup your /etc/pve and VMs.

 

[xigloo]

Here is the official ZFS documentation on HW raid and why its a bad idea to use it. So yeah, I would do a fresh install. Isn't that hard if you backup your /etc/pve and VMs.

thanks a lot Dunuin... /etc/pve , is it for configuration? right ? :] i proceed with a fresh install

 

[Dunuin]

/etc/pve is where all the proxmox configuration files (storages, network, firewall rules and so on) are stored.

 

[xigloo]

Hello Dunuin, i'm seeing about turn off RAID1 hardware on Dell R530 server to configure ZFS proxmox but, i've just another doubth; in your opinion, if i convert the 2 disks in NON-RAID mode, and they remain connected to PERC raid controller , is it right way or also must i change RAID controller with a normal sata controller?

 

[Dunuin]

You need a HBA or normal SATA controller without any raid, caching, backup battery and so on. You don't want any additional abstraction layer between ZFS and your drives. ZFS really needs to access the drives directly without anything manipulation data in between.

If you don't need enhanced features like blocklevel compression, deduplication, replication, self-healing filesystem (bit rot protection) you could ignore ZFS and just use HW raid with LVM thin ontop of it. That would save some RAM and should be faster but your data would not be that resiliant.

 

[xigloo]

my need was a ssd read cache ( for this , ZFS it's necessary if i don't think wrong) but, for a safety of system, i will put away this solution , i prefer a saftety system agaist a most speed system, if i must chose between one of them

 

[Dunuin]

Then ZFS would be your best option. But LVM should also allow for write and read SSD caching (google for "dm-cache").

 

[xigloo]

okay, i try to search about dm-cache thank you

 

[hepo]

Asking for friend
He is rending Fujitsu bare metal box with PRAID EP420i (LSA 3108).
The disk are configured as JBOD's on the controller, there is no battery.

What would you recon, will this be an issue for ZFS?

He asked to remove the RAID controller but was declined by the renting company, flashing the controller in IT is also not an option.
The drive SMART details are detected correctly.

Thanks

 

[xigloo]

Asking for friend
He is rending Fujitsu bare metal box with PRAID EP420i (LSA 3108).
The disk are configured as JBOD's on the controller, there is no battery.

What would you recon, will this be an issue for ZFS?

He asked to remove the RAID controller but was declined by the renting company, flashing the controller in IT is also not an option.
The drive SMART details are detected correctly.

Thanks

I think PRAID EP420i (LSA 3108) have a cache on board, an this particular isn't good for proxmox ZFS mode. it could get problems...

 

[xigloo]

Dunuin, excuse me an aswer again on Perc H330. If i delete array HW RAID1 on it, and create hw RAID0 on each hdd, and than install proxmox Ve 6 in ZFS RAID1 selecting these 2 hw raid0 disks, can it would be a good work around with minimal risk than ZFS installed on Hw RAID1 ? Or you think i must forget any PERC mode excluding PERC from server?

 

[Dunuin]

No you really need no raid at all. PERC H330 should only be used if crossflashed into IT-mode. That way it will be a normal HBA without any raid.

 

[xigloo]

et voilà, i'm here again :] argument about HW RAID and ZFS is very amazing;
i've read procedure find in "crossflashed" link posted, and after i've find a procedure posted by Dell that seem most easly in apparence. Can this procedure works well like "crossflashed" procedure, in your opinion?

https://www.dell.com/support/manual...cc87e1-d534-451a-9947-56f1175886c5&lang=en-us

thanks a lot for your precious advice, Dunuin

 

[Dunuin]

Sounds good.

 

[Dunuin]

And HW raid usually can't fix corrupted data because it is not checksumming every block. So not that great if you really care about data integrity.