On Sunday, December 20, 2015 02:15:33 AM cov...@ccs.covici.com wrote: > cov...@ccs.covici.com wrote: > > Rich Freeman <ri...@gentoo.org> wrote: > > > On Sat, Dec 19, 2015 at 2:56 AM, <cov...@ccs.covici.com> wrote: > > > > I was never able to get either zfs or btrfs to work correctly, zfs was > > > > very vulnerable -- I forgot to export a zfs on a usb drive and got an > > > > enless loop of processes untill I rebooted. Btrfs never did work for > > > > me, I created a pool, copied my root file system, usr and var into > > > > ssubvolumes, and copied my files, but when I would boot into it, > > > > everything was messed up, processes thought files were missing, very > > > > strange. So, how did you set up either one of those -- I would love > > > > to > > > > use it because I have ssds and I don't want to rely on their firmware > > > > either. > > > > > > Well, I don't have much personal experience with zfs, but the ZFS on > > > Linux lead is a Gentoo dev, so you're in good company there all the > > > same. I personally use btrfs. > > > > > > The obvious caveat is that it is still relatively experimental, and > > > raid5/6 is VERY experimental. I plan to convert to raid5/6 at a > > > future date but am staying away from it for now (and a selling point > > > of btrfs is that reshaping in-place is easy). > > > > > > I can't really vouch for what went wrong with your migration. It > > > could be anything from a failure to preserve all your file attributes > > > to something with btrfs itself or your bootloader config/etc. It > > > isn't hard to do a new install in btrfs though, and you can always > > > mess with it in a VM, or even mess with doing migrations in a VM. > > > > > > My btrfs install notes are at: > > > https://docs.google.com/document/d/1VJlJyYLTZScta9a81xgKOIBjYsG3_VfxxmUS > > > xG23Uxg/edit?usp=sharing (I still plan to merge this stuff into the > > > handbook. Maybe a good holiday project... Oh, and if it isn't already > > > obvious anybody can add comments and half this list seems to have > > > already done so.) > > > > > > Oh, for a boot image I tend to use system rescue CD since it has all > > > the necessary userspace and is gentoo-based (and you can always emerge > > > --sync and install whatever you need inside it). I tend to use the > > > alternate kernel since it is newer, and with btrfs newer tends to be > > > better. In production I'm currently on 3.18 eyeing an upgrade to 4.1. > > > I tend to stay on the latest longterm, but not when they are first > > > declared as longterm. That seems to be the sweet spot for getting > > > btrfs features and bugfixes, but not getting as many of the > > > regressions. I use grub2/dracut to boot, and that is in my guide. > > > > > > If you follow those notes for a stage3 install it should "just work." > > > If you want to mess around I suggest just doing a vanilla install on a > > > VM once to validate that it works for you and then tweak from a > > > position of strength. > > > > Thanks. I will check out your notes and figure out something -- it was > > definitely strange. I have a vm I can play with -- its older, but I can > > bring it up to date and see what happens. > > > > Thanks again. > > One thing I was thinking of -- since I like separate file systems for > each major directory i.e. separate /usr, /var, /home, /tmp and even > /var/tmp/portage, I thought I would make btrfs file systems using lvm. > The advantage is that I use lvm already, so this would be easy for me to > do and safer in case one of them goes south and easier to control space > allocation. The only disadvantage I can see is if its a performance > hit, does anyone have any knowledge of that is true?
I only played around with ZFS so far, but I believe the same holds true for BTRFS. These new filesystems should really be handed control of the entire disk as they already include LVM-like functionality. You can create subvolumes and limit those to different sizes if you so desire. When using an additional layer between ZFS/BTRFS and the discs, you will loose performance with no gain in flexibility. -- Joost
