ZFS on Linux
From Lolly's Wiki
Grub
Create /etc/udev/rules.d/99-local-grub.rules with this content:
# Create by-id links in /dev as well for zfs vdev. Needed by grub
# Add links for zfs_member only
KERNEL=="sd*[0-9]", IMPORT{parent}=="ID_*", ENV{ID_FS_TYPE}=="zfs_member", SYMLINK+="$env{ID_BUS}-$env{ID_SERIAL}-part%n"
Virtualbox on ZVols
If you use ZVols as rawvmdk-device in VirtualBox as normal user (vmuser in this example) create /etc/udev/rules.d/99-local-zvol.rules with this content:
KERNEL=="zd*" SUBSYSTEM=="block" ACTION=="add|change" PROGRAM="/lib/udev/zvol_id /dev/%k" RESULT=="rpool/VM/*" OWNER="vmuser"
vmuser@virtualbox-server:~$ VBoxManage internalcommands createrawvmdk -filename /var/data/VMs/dev/Solaris10.vmdk -rawdisk /dev/zvol/rpool/VM/Solaris10
Setup Ubuntu 16.04 with ZFS root
Most is from here Ubuntu-16.04-Root-on-ZFS.
Boot Ubuntu Desktop (alias Live CD) and choose "try out".
Get the right ashift value
For example to get sda and sdb:
# lsblk -o NAME,PHY-SeC,LOG-SEC /dev/sd{a,b} | awk 'function exponent (value) {for(i=0;value>1;i++){value/=2;}; return i;}{if($2 ~ /[0-9]+/){print $0,exponent($2)}else{print$0,"ashift"}}'
NAME PHY-SEC LOG-SEC ashift
sda 512 512 9
├─sda1 512 512 9
├─sda2 512 512 9
├─sda3 512 512 9
└─sda4 512 512 9
sdb 4096 512 12
├─sdb1 4096 512 12
├─sdb2 4096 512 12
├─sdb3 4096 512 12
└─sdb4 4096 512 12
Connect it to your network
sudo -i
ifconfig ens160 <IP> netmask 255.255.255.0
route add default gw <defaultrouter>
echo "nameserver <nameserver>" >> /etc/resolv.conf
echo 'Acquire::http::Proxy "http://<user>:<pass>@<proxyhost>:<proxyport>";' >> /etc/apt/apt.conf
apt-add-repository universe
apt update
apt --yes install openssh-server
passwd ubuntu
Reconnect via ssh
apt install --yes debootstrap gdisk zfs-initramfs
sgdisk -g -a1 -n2:34:2047 -t2:EF02 /dev/disk/by-id/scsi-36000c2932cdb62febff0b5ac93786dd4
sgdisk -n9:-8M:0 -t9:BF07 /dev/disk/by-id/scsi-36000c2932cdb62febff0b5ac93786dd4
sgdisk -n1:0:0 -t1:BF01 /dev/disk/by-id/scsi-36000c2932cdb62febff0b5ac93786dd4
zpool create -f -o ashift=12 \
-O atime=off \
-O canmount=off \
-O compression=lz4 \
-O normalization=formD \
-O mountpoint=/ \
-R /mnt \
rpool /dev/disk/by-id/scsi-36000c2932cdb62febff0b5ac93786dd4-part1
zfs create -o canmount=off -o mountpoint=none rpool/ROOT
zfs create -o canmount=noauto -o mountpoint=/ rpool/ROOT/ubuntu
zfs mount rpool/ROOT/ubuntu
zfs create -o setuid=off rpool/home
zfs create -o mountpoint=/root rpool/home/root
zfs create -o canmount=off -o setuid=off -o exec=off rpool/var
zfs create -o com.sun:auto-snapshot=false rpool/var/cache
zfs create rpool/var/log
zfs create rpool/var/spool
zfs create -o com.sun:auto-snapshot=false -o exec=on rpool/var/tmp
zfs create -V 4G -b $(getconf PAGESIZE) -o compression=zle \
-o logbias=throughput -o sync=always \
-o primarycache=metadata -o secondarycache=none \
-o com.sun:auto-snapshot=false rpool/swap
cp -p {,/mnt}/etc/apt/apt.conf
export http_proxy=$(awk '/Acquire::http::Proxy/{gsub(/\"/,"");gsub(/;$/,"");print $2}' /mnt/etc/apt/apt.conf)
echo -n xenial{,-security,-updates} | \
xargs -n 1 -d ' ' -I{} echo "deb http://archive.ubuntu.com/ubuntu {} main universe" > /mnt/etc/apt/sources.list
chmod 1777 /mnt/var/tmp
debootstrap xenial /mnt
zfs set devices=off rpool
HOSTNAME=Template-VM
echo ${HOSTNAME} > /mnt/etc/hostname
printf "127.0.1.1\t%s\n" "${HOSTNAME}" >> /mnt/etc/hosts
INTERFACE=$(ip a s scope global | awk 'NR==1{gsub(/:$/,"",$2);print $2;}')
printf "auto %s\niface %s inet dhcp\n" "${INTERFACE}" "${INTERFACE}" > /mnt/etc/network/interfaces.d/${INTERFACE}
mount --rbind /dev /mnt/dev
mount --rbind /proc /mnt/proc
mount --rbind /sys /mnt/sys
cp -p {,/mnt}/etc/apt/apt.conf
echo -n xenial{,-security,-updates} | \
xargs -n 1 -d ' ' -I{} echo "deb http://archive.ubuntu.com/ubuntu {} main universe" > /mnt/etc/apt/sources.list
chroot /mnt /bin/bash --login
locale-gen en_US.UTF-8
echo 'LANG="en_US.UTF-8"' > /etc/default/locale
LANG="en_US.UTF-8"
dpkg-reconfigure tzdata
ln -s /proc/self/mounts /etc/mtab
apt update
apt install --yes ubuntu-minimal
apt install --yes --no-install-recommends linux-image-generic
apt install --yes zfs-initramfs
apt install --yes openssh-server
apt install --yes grub-pc
addgroup --system lpadmin
addgroup --system sambashare
passwd
grub-probe /
update-initramfs -c -k all
vi /etc/default/grub
Comment out: GRUB_HIDDEN_TIMEOUT=0
Remove quiet and splash from: GRUB_CMDLINE_LINUX_DEFAULT
Uncomment: GRUB_TERMINAL=console
update-grub
grub-install /dev/disk/by-id/scsi-36000c2932cdb62febff0b5ac93786dd4
zfs snapshot rpool/ROOT/ubuntu@install
exit
mount | grep -v zfs | tac | awk '/\/mnt/ {print $3}' | xargs -i{} umount -lf {}
zpool export rpool
reboot
apt install --yes cryptsetup
echo cryptswap1 /dev/zvol/rpool/swap /dev/urandom swap,cipher=aes-xts-plain64:sha256,size=256 >> /etc/crypttab
systemctl daemon-reload
systemctl start systemd-cryptsetup@cryptswap1.service
echo /dev/mapper/cryptswap1 none swap defaults 0 0 >> /etc/fstab
swapon -av
Kernel settings for ZFS
root@zfshost:~# modprobe -c | grep zfs | grep -v alias
options zfs zfs_arc_max=10737418240
options zfs zfs_vdev_scrub_min_active=24
options zfs zfs_vdev_scrub_max_active=64
options zfs zfs_vdev_sync_write_min_active=8
options zfs zfs_vdev_sync_write_max_active=32
options zfs zfs_vdev_sync_read_min_active=8
options zfs zfs_vdev_sync_read_max_active=32
options zfs zfs_vdev_async_read_min_active=8
options zfs zfs_vdev_async_read_max_active=32
options zfs zfs_vdev_async_write_min_active=8
options zfs zfs_vdev_async_write_max_active=32
options zfs l2arc_write_max=524288000
options zfs zfs_top_maxinflight=512
options zfs zfs_resilver_min_time_ms=8000
options zfs zfs_resilver_delay=0
root@zfshost:~# modprobe --show-depends zfs
insmod /lib/modules/4.15.0-58-generic/kernel/spl/spl.ko
insmod /lib/modules/4.15.0-58-generic/kernel/zfs/znvpair.ko
insmod /lib/modules/4.15.0-58-generic/kernel/zfs/zcommon.ko
insmod /lib/modules/4.15.0-58-generic/kernel/zfs/icp.ko
insmod /lib/modules/4.15.0-58-generic/kernel/zfs/zavl.ko
insmod /lib/modules/4.15.0-58-generic/kernel/zfs/zunicode.ko
insmod /lib/modules/4.15.0-58-generic/kernel/zfs/zfs.ko zfs_arc_max=10737418240 zfs_vdev_scrub_min_active=24 zfs_vdev_scrub_max_active=64 zfs_vdev_sync_write_min_active=8 zfs_vdev_sync_write_max_active=32 zfs_vdev_sync_read_min_active=8 zfs_vdev_sync_read_max_active=32 zfs_vdev_async_read_min_active=8 zfs_vdev_async_read_max_active=32 zfs_vdev_async_write_min_active=8 zfs_vdev_async_write_max_active=32 l2arc_write_max=524288000 zfs_top_maxinflight=512 zfs_resilver_min_time_ms=8000 zfs_resilver_delay=0
ARC Cache
Get the current usage of cache
# cat /proc/spl/kstat/zfs/arcstats |grep c_
c_min 4 521779200
c_max 4 1073741824
arc_no_grow 4 0
arc_tempreserve 4 0
arc_loaned_bytes 4 0
arc_prune 4 25360
arc_meta_used 4 493285336
arc_meta_limit 4 805306368
arc_dnode_limit 4 80530636
arc_meta_max 4 706551816
arc_meta_min 4 16777216
sync_wait_for_async 4 357
arc_need_free 4 0
arc_sys_free 4 260889600
Limit the cache without reboot non permanent
For example limit it to 512MB (which is too small for production environments, just an example...):
# echo "$[512*1024*1024]" > /sys/module/zfs/parameters/zfs_arc_max
Now you have to drop the caches:
# echo 3 > /proc/sys/vm/drop_caches
Make the cache limit permanent
For example limit it to 512MB (which is too small for production environments, just an example...):
# echo "options zfs zfs_arc_max=$[512*1024*1024]" >> /etc/modprobe.d/zfs.conf
After reboot this value take effect.
Backup ZFS settings
A little script which may be used on your own risk.
#!/bin/bash
# Written by Lars Timmann <L@rs.Timmann.de> 2018
# Tested on solaris 11.3 & Ubuntu Linux
# This script is a rotten bunch of code... rewrite it!
AWK_CMD=/usr/bin/gawk
ZPOOL_CMD=/sbin/zpool
ZFS_CMD=/sbin/zfs
ZDB_CMD=/sbin/zdb
function print_local_options () {
DATASET=$1
OPTION=$2
EXCLUDE_REGEX=$3
${ZFS_CMD} get -s local -Ho property,value -p ${OPTION} ${DATASET} | while read -r property value
do
if [[ ! ${property} =~ ${EXCLUDE_REGEX} ]]
then
if [ "_${property}_" == "_share.*_" ]
then
print_local_options "${DATASET}" 'share.all' '^$'
else
printf '\t-o %s=%s \\\n' "${property}" "${value}"
fi
fi
done
}
function print_filesystem () {
ZFS=$1
printf '%s create \\\n' "${ZFS_CMD}"
print_local_options "${ZFS}" 'all' '^$'
printf '\t%s\n' "${ZFS}"
}
function print_filesystems () {
ZPOOL=$1
for ZFS in $(${ZFS_CMD} list -Ho name -t filesystem -r ${ZPOOL})
do
if [ ${ZFS} == ${ZPOOL} ] ; then continue ; fi
printf '#\n## Filesystem: %s\n#\n\n' "${ZFS}"
print_filesystem ${ZFS}
printf '\n'
done
}
function print_volume () {
ZVOL=$1
volsize=$(${ZFS_CMD} get -Ho value volsize ${ZVOL})
volblocksize=$(${ZFS_CMD} get -Ho value volblocksize ${ZVOL})
printf '%s create \\\n\t-V %s \\\n\t-b %s \\\n' "${ZFS_CMD}" "${volsize}" "${volblocksize}"
print_local_options "${ZVOL}" 'all' '(volsize|refreservation)'
printf '\t%s\n' "${ZVOL}"
}
function print_volumes () {
ZPOOL=$1
for ZVOL in $(${ZFS_CMD} list -Ho name -t volume -r ${ZPOOL})
do
printf '#\n## Volume: %s\n#\n\n' "${ZVOL}"
print_volume ${ZVOL}
printf '\n'
done
}
function print_vdevs () {
ZPOOL=$1
${ZDB_CMD} -C ${ZPOOL} | ${AWK_CMD} -F':' '
$1 ~ /^[[:space:]]*type$/ {
gsub(/[ ]+/,"",$NF);
type=substr($NF,2,length($NF)-2);
if ( type == "mirror" ) {
printf " \\\n\t%s",type;
}
}
$1 ~ /^[[:space:]]*path$/ {
gsub(/[ ]+/,"",$NF);
vdev=substr($NF,2,length($NF)-2);
printf " \\\n\t%s",vdev;
}
END {
printf "\n";
}
'
}
function print_zpool () {
ZPOOL=$1
printf '#############################################################\n'
printf '#\n## ZPool: %s\n#\n' "${ZPOOL}"
printf '#############################################################\n\n'
printf '%s create \\\n' "${ZPOOL_CMD}"
print_local_options "${ZPOOL}" 'all' '/@/'
printf '\t%s' "${ZPOOL}"
print_vdevs "${ZPOOL}"
printf '\n'
printf '#############################################################\n\n'
print_filesystems "${ZPOOL}"
print_volumes "${ZPOOL}"
}
OS=$(uname -s)
eval $(uname -s)=1
HOSTNAME=$(hostname)
printf '#############################################################\n'
printf '# Hostname: %s\n' "${HOSTNAME}"
printf '#############################################################\n\n'
for ZPOOL in $(${ZPOOL_CMD} list -Ho name)
do
print_zpool ${ZPOOL}
done
