lxc permission and barriers

[sahostking]

Hi guys,

I've had massive drop in performance from openvz (proxmox 3) to LXC (proxmox 4) with exact same amount of VPSs.

HW raid in raid 10 with 6 x enterprise Sata disks

I am trying to set barrier=0 but not sure if its set or not:

fstab contents:

# <file system> <mount point> <type> <options> <dump> <pass>
/dev/pve/root / ext4 errors=remount-ro,barrier=0,noatime 0 1
/dev/pve/swap none swap sw 0 0
proc /proc proc defaults 0 0


cat /proc/mounts

sysfs /sys sysfs rw,nosuid,nodev,noexec,relatime 0 0
proc /proc proc rw,relatime 0 0
udev /dev devtmpfs rw,relatime,size=10240k,nr_inodes=8229823,mode=755 0 0
devpts /dev/pts devpts rw,nosuid,noexec,relatime,gid=5,mode=620,ptmxmode=666 0 0
tmpfs /run tmpfs rw,nosuid,relatime,size=13173452k,mode=755 0 0
/dev/dm-0 / ext4 rw,noatime,nobarrier,errors=remount-ro,data=ordered 0 0
securityfs /sys/kernel/security securityfs rw,nosuid,nodev,noexec,relatime 0 0
tmpfs /dev/shm tmpfs rw,nosuid,nodev 0 0
tmpfs /run/lock tmpfs rw,nosuid,nodev,noexec,relatime,size=5120k 0 0
tmpfs /sys/fs/cgroup tmpfs rw,mode=755 0 0
cgroup /sys/fs/cgroup/systemd cgroup rw,nosuid,nodev,noexec,relatime,xattr,release_agent=/lib/systemd/systemd-cgroups-agent,name=systemd 0 0
pstore /sys/fs/pstore pstore rw,nosuid,nodev,noexec,relatime 0 0
cgroup /sys/fs/cgroup/cpuset cgroup rw,nosuid,nodev,noexec,relatime,cpuset,clone_children 0 0
cgroup /sys/fs/cgroup/cpu,cpuacct cgroup rw,nosuid,nodev,noexec,relatime,cpu,cpuacct 0 0
cgroup /sys/fs/cgroup/blkio cgroup rw,nosuid,nodev,noexec,relatime,blkio 0 0
cgroup /sys/fs/cgroup/memory cgroup rw,nosuid,nodev,noexec,relatime,memory 0 0
cgroup /sys/fs/cgroup/devices cgroup rw,nosuid,nodev,noexec,relatime,devices 0 0
cgroup /sys/fs/cgroup/freezer cgroup rw,nosuid,nodev,noexec,relatime,freezer 0 0
cgroup /sys/fs/cgroup/net_cls,net_prio cgroup rw,nosuid,nodev,noexec,relatime,net_cls,net_prio 0 0
cgroup /sys/fs/cgroup/perf_event cgroup rw,nosuid,nodev,noexec,relatime,perf_event,release_agent=/run/cgmanager/agents/cgm-release-agent.perf_event 0 0
cgroup /sys/fs/cgroup/hugetlb cgroup rw,nosuid,nodev,noexec,relatime,hugetlb,release_agent=/run/cgmanager/agents/cgm-release-agent.hugetlb 0 0
cgroup /sys/fs/cgroup/pids cgroup rw,nosuid,nodev,noexec,relatime,pids,release_agent=/run/cgmanager/agents/cgm-release-agent.pids 0 0
systemd-1 /proc/sys/fs/binfmt_misc autofs rw,relatime,fd=21,pgrp=1,timeout=300,minproto=5,maxproto=5,direct 0 0
mqueue /dev/mqueue mqueue rw,relatime 0 0
debugfs /sys/kernel/debug debugfs rw,relatime 0 0
hugetlbfs /dev/hugepages hugetlbfs rw,relatime 0 0
fusectl /sys/fs/fuse/connections fusectl rw,relatime 0 0
rpc_pipefs /run/rpc_pipefs rpc_pipefs rw,relatime 0 0
tmpfs /run/lxcfs/controllers tmpfs rw,relatime,size=100k,mode=700 0 0
pids /run/lxcfs/controllers/pids cgroup rw,relatime,pids,release_agent=/run/cgmanager/agents/cgm-release-agent.pids 0 0
hugetlb /run/lxcfs/controllers/hugetlb cgroup rw,relatime,hugetlb,release_agent=/run/cgmanager/agents/cgm-release-agent.hugetlb 0 0
perf_event /run/lxcfs/controllers/perf_event cgroup rw,relatime,perf_event,release_agent=/run/cgmanager/agents/cgm-release-agent.perf_event 0 0
net_cls,net_prio /run/lxcfs/controllers/net_cls,net_prio cgroup rw,relatime,net_cls,net_prio 0 0
freezer /run/lxcfs/controllers/freezer cgroup rw,relatime,freezer 0 0
devices /run/lxcfs/controllers/devices cgroup rw,relatime,devices 0 0
memory /run/lxcfs/controllers/memory cgroup rw,relatime,memory 0 0
blkio /run/lxcfs/controllers/blkio cgroup rw,relatime,blkio 0 0
cpu,cpuacct /run/lxcfs/controllers/cpu,cpuacct cgroup rw,relatime,cpu,cpuacct 0 0
cpuset /run/lxcfs/controllers/cpuset cgroup rw,relatime,cpuset,clone_children 0 0
name=systemd /run/lxcfs/controllers/name=systemd cgroup rw,relatime,xattr,release_agent=/lib/systemd/systemd-cgroups-agent,name=systemd 0 0
lxcfs /var/lib/lxcfs fuse.lxcfs rw,nosuid,nodev,relatime,user_id=0,group_id=0,allow_other 0 0
cgmfs /run/cgmanager/fs tmpfs rw,relatime,size=100k,mode=755 0 0


Note I did use nabarrier before and remounted using mount -a and it addes it I see to:
/dev/dm-0 / ext4 rw,noatime,nobarrier,errors=remount-ro,data=ordered 0 0

But does that means lxc containers are using it to?

 

[LnxBil]

If the containers are based on LVM with their own ext4, then no. You need to change it for each container manually.

BTW: Consider using ZFS for LXC, much, much smoother and superior in features.

 

[dietmar]

You can use tunefs on the container image to set/change default mount option.