Advice on moving from ZFS to BTRFS

[Maher Khalil]

I tried proxmox 6 and 7 in production with ZFS and RAM was the bottleneck
Now, I am thinking to move from ZFS to BTRFS that my customers need snapshot and fore data safety and myself want better RAM saving
any advice in this part

 

[mac.linux.free]

I did it on 1 host but the features are not complete

 

[mac.linux.free]

so only snapshots are working...replication and raid5 not

 

[Maher Khalil]

what about RAM performance. is it like ZFS or better?
i need only snapshot with raid 1 for mirror disks

 

[mac.linux.free]

yes do have more ram available for your vms

 

[Maher Khalil]

Thank you very much
I will use it

 

[Maher Khalil]

BTRFS can do software raid 1 so no need for hardware raid controller, right?

 

[tjk]

Why don't you just limit the amount of RAM ZFS can use instead of moving to BTRFS?

 

[Maher Khalil]

I think limiting of ZFS RAM will not resolve the issue of it is eating RAM
RAM is expensive and required for customers
I like ZFS and I am using it in my private PC but I think it is suitable for private cloud not for public cloud where cost is very important

 

[tjk]

https://forum.proxmox.com/threads/disable-zfs-arc-or-limiting-it.77845/ says you can limit the RAM that ARC will use, why won't this work?

 

[Maher Khalil]

Do you think zfs desert that while I can replace it with btrfs?

 

[tjk]

Do you think zfs desert that while I can replace it with btrfs?

Not sure I understand the question, but I would trust ZFS before I trust btrfs, at least for me personally.

 

[Maher Khalil]

I understand you
I appreciate your help
Thank you

 

[Dunuin]

ZFS by default will use up to 50% of the hosts RAM for its ARC for caching. So if you for example got 2x 1TB SSDs and 64GB RAM it will use up to 32GB RAM. But ZFS can easily work with way less RAM. For such a setup a 4 GB ARC should work too. I wouldn't recommend to limit the ARC too low, because it can get slow, but you can definitly limit it to more reasonable amounts. Just lower the ARC step by step and run arc_summary to check when the hit rates and free dnode/metadata cache get too low and then stop lowering it.

 

[Maher Khalil]

i will try that
Appreciate your help
Thank you