Switching from HW RAID TO SW RAID

[juancarlo2596]

Hi, we do have a Dell R820 Server with Proxmox 8 installed

Specs:
4x Intel(R) Xeon(R) CPU E5-4640 v2
512GB RAM
8x Intel SSD D3-S4610 3.84TB in HW RAID6 (Dell Perc H710P)

Planning to get rid of the RAID card and use a LSI 9207-8i IT Mode Flashed and rebuild proxmox from HW Raid 6 to ZFS RAID-Z3

1. Is it much better to use ZFS rather than HW Raid?
2. Am I still able to use the standard directory based system (browseable /var/lib/vz/images incase OS might crash, backups are already common but still wanted to copy raw disks from directory)? Don't want to use lvm storage
3. Is it way more easier to rebuild data on ZFS incase of a drive failure?
4. Is I/O way much better on ZFS?

 

[Dunuin]

proxmox from HW Raid 6 to ZFS RAID-Z3

Keep in mind that you need to increase the block size of that ZFS storage from 8K to something like 256K in case you don't want to lose tons of capacity (only 38% raw capacity lost instead of 75%) due to padding overhead when running a 8 disk raidz3 with ashift=12.

1. Is it much better to use ZFS rather than HW Raid?

If you don't care that much about performance and more about data integrity, yes.

2. Am I still able to use the standard directory based system (browseable /var/lib/vz/images incase OS might crash, backups are already common but still wanted to copy raw disks from directory)? Don't want to use lvm storage

"/var/lib/vz/images" will be a directory storage that is part of your root filesystem which is a dataset on that ZFS pool.

3. Is it way more easier to rebuild data on ZFS incase of a drive failure?

I would say more difficult. At least in case you are also booting from that pool. AS you then would need to manually clone the partition table and sync the bootloader before you can replace that disk. See chapter "Changing a failed bootable device": https://pve.proxmox.com/wiki/ZFS_on_Linux#_zfs_administration

4. Is I/O way much better on ZFS?

Probably worse because of all the additional features and data integrity checks that add overhead.