If you’re running DragonFly on a very low-end system, you may be wondering about memory requirements for Hammer. Hammer is much less RAM-hungry than ZFS, so it looks like you can get away with 128M, as long as you don’t mind the occasional error message. You can manually tweak settings for it if you like. 256M is plenty.
It still strikes me as odd to consider systems with less than 1G of RAM as “low-memory”. What rich times we live in!
I think of anything under 4GB of RAM as low-memory – how about that?!
And yet my server runs happily with 512MB :-)
I’ve heard the recommendation that you need 2GB RAM for every 1TB of ZFS. I wonder what the same “rule of thumb” for UFS2 and HAMMER would be.
Heh, my first computer had 2MB RAM, upgraded to 4MB. It would take a bit of tweaking to get modern BSD’s to run on that… A lot of things have become very inefficient – it just blows my mind that the Gnome taskbar time display component eats up about 10MB!
For long time (more then a year) my FreeBSD 8.1 based home NAS with 2 x 2TB drives (2TB ZFS mirror) worked nice with 512MB RAM, the only reasons for reboots were power outages that happen used to happen from time to time in a ‘not-a-server-room’ environment ;)
I’ve run a pair of 1.5 TB HAMMER filesystems for a while with 256 MB of RAM; worked well.
I think that 2GB ram for 1TB of disk space for ZFS is only if you are running de-dup. BTW, I used to run FreeNAS 8.1 on a dell GX280 desktop with a 1.5 TB hard drive and 3.5GB of ram and it ran fairly well. I have since replaced it with dfly 2.10 with hammer and it seems to run a lot faster. I cant quantify it in anyway but everything just feels faster – NFS/SAMBA especially. I cant wait until 2.12 is released.