Le 05/11/2014 13:06, Kostas Koudaras a écrit :

Great idea for an article Jdd :D

thanks. I have always ideas to give work to others - but usually I try not to write them :-(

Maybe you can throw some questions, then I willl throw some more and

May be we can go practical. What happen when you want to install a fresh 13.2... * you get a nice screen (yast install, I guess) a bit simpler than we are used to * when partitionning is the subject, you are offered to use BTRFS on /, with a lot of subvolumes. This was never the case before, so even an experienced user my wonder. Specially when installing on somebody else computer, what I do nearly constantly. What is I have to change a bit the defaults? There are no subvolumes on /home, I did not investigate what was the /home partition existed already (and was not formatted by the install, good) I understand these subvolumes are dynamic (=expandables/shrinkables) locations, but what is the use of having them in the first place? Noticed the / was hudge, 40Gb when usually only 20Gb was used (and my test disk is only 240Gb). Guess it is for snapshots. I'm used of VirtualBox snapshots, is that the same? after the install ends, found a new yast menu: snapper. Ah! found interesting doc http://doc.opensuse.org/products/draft/SLES/SLES-admin_sd_draft/cha.snapper.... oh! yes: "As a rule of thumb you should consider using twice the size than you normally would" "Apart from the YaST and zypper snapshots, Snapper creates hourly snapshots of the system partition (/)" this page have to be printed! this may explain my initial question: " For some directories we decided to disable snapshotting, e.g. /var/log since reverting logs makes searching for problems difficult. To exclude a path from snapshotting we create a subvolume for that path. The following mount points are excluded from snapshotting on SUSE Linux Enterprise Server: /opt /srv /tmp /var/crash /var/log /var/run /var/spool /var/tmp " buthis doc is draftn les and seems old. also founnd is http://events.linuxfoundation.org/sites/events/files/slides/EndUserSummit_20... http://www.novell.com/feeds/nih/wp-content/uploads/2012/05/SUS18_lab.pdf (not read yet) -- To unsubscribe, e-mail: opensuse+unsubscribe@opensuse.org To contact the owner, e-mail: opensuse+owner@opensuse.org

On 11/05/2014 08:24 AM, Kai-Uwe Behrmann wrote:

Am 05.11.2014 12:52, schrieb jdd:

...

So I want to learn why there are here, what's for, benefits and may be drawbacks...

My recent factory installation defaulted to btrfs. As my development machine has many test partitions, oS was going to be around 10GB. Not much, but enough for previous linux installs. Today that oS factory installation refused to run the usual daily X session. Lots of disk(ssd) i/o slowed down the machine. df showed some hundreds MB free space. But that is not relyable as the btrfs wiki tells. That wiki does not tell how to disable features to get that system running smooth again. Additionally yast stopped on the command line. After removing files it was still slow. btrfs check did not show any errors. ATM I must say for me btrfs is a failure. Right now I reinstall oS-13.2 using ext4.

Hope you will find some answeres including better documentation and for easier trouble shooting to improve the situation with the default offered file system in oS-13.2.

kind regards Kai-Uwe

PS: I dont think the above described behaviour is a bug. Its just a ignored usecase together with lax documentation.

One gotcha that *IS* documented (but as a feeature not a problem) but often overlooked, well I overlooked it, is that by default snapper is taking backups. With the one volume approach that means every time you run yast/zypper or some other things it takes snapshot in a (hidden with a dot-name) subvolume. The bug, to my mind, is that the snapshot subvolume set up at install doesn't have a quota, a limit, so eventually it eats up space. For some reason I don't understand that didn't show up in the 'df'. As I say, it *IS* documented. Its just not documented at a gotcha! See snapper(8) for the command line interface. There is supposed to be a daily cleanup but I never saw it working. You can turn snapper down or off and you can remove the /.snapshots subvolume. You may need to do some additional cleanup after that. Disbaling snapper in the config files looks like the best approach. I started with a 10G root Fs but with separate /boot, /home and /usr and nothing in /srv. I'm now running a 20G root fs. Filesystem Size Used Avail Use% Mounted on /dev/mapper/vgmain-vROOT 20G 8.6G 9.9G 47% / /dev/sda1 1.9G 245M 1.5G 14% /boot /dev/mapper/vgmain-vSRV 4.8G 12M 4.6G 1% /srv /dev/mapper/vgmain-vTMP 9.8G 89M 9.2G 1% /tmp /dev/mapper/vgmain-vHome 8.0G 5.9G 2.2G 73% /home /dev/mapper/vgmain-vUsrShare 5.0G 2.4G 2.7G 47% /usr/share I suppose I could separate out /usr again, but I think it would be more trouble than its worth. I have many 16G USB sticks. Sadly the ones give out at trade shows seem to be all 8G :-( -- A: Yes. > Q: Are you sure? >> A: Because it reverses the logical flow of conversation. >>> Q: Why is top posting frowned upon? -- To unsubscribe, e-mail: opensuse+unsubscribe@opensuse.org To contact the owner, e-mail: opensuse+owner@opensuse.org

On 11/05/2014 09:01 AM, Malcolm wrote:

I modify the /etc/snapper/configs/root file to my needs, by default now the timeline is off (as in no hourly snapshots).

RIGHT! I can't imagine why hourly snapshots is the install default. Unless there is a quota/limit this is a sure way to render the disk unusable very quickly. Hourly snapshots are for the paranoid. Or for developers who are too lazy to use a proper cvs. -- A: Yes. > Q: Are you sure? >> A: Because it reverses the logical flow of conversation. >>> Q: Why is top posting frowned upon? -- To unsubscribe, e-mail: opensuse+unsubscribe@opensuse.org To contact the owner, e-mail: opensuse+owner@opensuse.org