Sticking with gmirror or moving to zfs mirror for upgrade

M

megaplaychop

Hi there,

I have a question regarding an upcoming upgrade for a box that I use at home to serve files for the other computers (mostly media center videos for the windows box in the living room and docs through samba) and as a git repository for a few home projects. Aside from that it runs a couple of other things like nginx + php-fpm, vsftp, cups but that's for toying around or the home network only (4/5 computers in total).

I currently run FreeBSD 6.4 (I think... It's a 6 something, haven't had to login into it it's been so stable :)) on an Intel E2160 that has 3 drives (SATA, nothing fancy) attached to it. 1 drive is for the OS and the other 2 are currently setup as a 1 TB mirror using gmirror. I currently have 2GB of RAM in the box.

I want to upgrade to version 9.2 within the next few weeks and also upgrade some of the hardware in there. I can't really upgrade the CPU as it's an LGA775 and it's tough to find new ones for a decent price now. I plan on putting in 4 GB of RAM and install brand new drives (WD blue 1 TB each). I want the same kind of setup for the drives. However I was considering using a ZFS mirror pool instead of gmirror.

I was wondering if people saw that as a Good Thing (tm) beyond the fact that ZFS is popular these days? I'm a bit worried my 4GB of RAM won't be enough and don't really want to reboot every now and then just because of ZFS, although I've read around that it should be fine with 4 GB of RAM. I'm content with gmirror although the write/concurrent read performance hasn't been stellar but I wouldn't exclude my hardware as the culprit for this.

Anyway any thoughts on this process are appreciated, I'm still spec'ing things around so I can make changes based on people's inputs :)

Many thanks in advance,

Greg
 
I ran the same kind of server with ZFS on only 2GB. Didn't tweak anything and it ran perfectly. It may not perform at it's best but it works and I never had any problems. For a home situation it was enough.
 
I originally had only a P4 with 2 GB of RAM for my home ZFS server. Originally had 4 disks in raidz1 booting off UFS on a USB stick. Then migrated the pool over to 2 disks in a mirror (much better performance), still booting off the USB stick.

Finally, migrated the server over to ZFS-on-root (no USB stick), added another pair of drives (so back to 4 drives, in two mirrors), and then upgraded to an Phenom-X4 CPU and 8 GB of RAM (64-bit OS install).

So 2 GB is definitely doable. Ran that way for 2 or 3 years (FreeBSD 8.x through 9.0) without many issues. The biggest issue was the occasional system lockup due (I'm guessing) memory fragmentation if too many torrents were writing to the disk and thrashing the ARC (this was a 32-bit system).

You just have to spend more time tweaking the ZFS-related tunables in /boot/loader.conf to limit the ARC, the amount of data in-flight, etc. If you have USB3 ports, consider adding a USB3 stick as an L2ARC device, although don't use too big of one, as it takes ARC space to manage L2ARC.
 
Hi there,

Just a quick follow-up to my little adventures if it can help anyone out there.

On the hardware side, I caved in and got 3x 1 TB WDC Blue HDDs. I also got a new CPU (Intel G2120), motherboard and case and fitted the whole thing with 8 GB of RAM.

As far as the setup of FreeBSD and my zpool mirror, I was very pleasantly surprised. Everything was not only easy but also fast to set up (brownie points for automatic partitioning during the guided install). the ZFS mirror was also easy to set up and in fact I had to double-check to make sure it was actually running since I figured it'd take more time and/or tweaking after my little experience with GEOM.

So all in all a really good and pain-free process. I even recycled the old machine to act as an rsync server in the basement to have some sort of backup there.

Thanks again for the help and info I got which helped me decide on which course to take. In the end, I think that for teh extra $150 it was worth having a newer CPU, more RAM etc. That way I have room to grow.

Take care everybody

Greg
 
Forgot to mention... The hardware changes allowed me to go 64bit which for ZFS I read in several places may be a good idea anyway.
 
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