The aim is showing that it is possible to create a low-cost storage, efficient and scalable, using opensource solutions. In the example below, I am using Ceph for scalability and reliability, combined with EnhanceIO to ensure very good performance.
Architecture
The idea was to create a storage with two parts: the storage itself (backing store) and a large cache to keep good performance on all data actually used. In fact, the volume needs may be important, but in the context of use for office, the data really used every day is only a portion of this storage. In my case, I intend to use Ceph deployed on low-cost hardware to ensure a scalable and reliable conformatble volume, based on small servers with large SATA drives. Data access will be via Samba shares on a slightly more powerful machine with an SAS Array to create a big cache. (Since Firefly, it would be more interesting to use ceph cache tiering)
Hardware
Ceph Part (Backing Store)
The material you choose should match the requirements of both performance and cost. To keep prices extremely competitive machines chosen here are based on Supermicro hardware without additional disk controller. Initially, the ceph storage is composed of 5 machines: store-01-02 store, store-03-04 store, store-05. Each node is build with simple CPU Core 2, 4 GB Memory, 1 SSD Drive (Intel 520 60GB) for system and Ceph journal and 3 SATA Drive of 3 TO (Seagate CS 3TB) with no specific Drive controller (Using onbord controller).
Samba / EnhanceIO Part (File Server and Cache)
The cache must be on the same server as the file server. In my case, I use Dell server with 10 sas drive 10k in Raid10 for the cache.
Network
I do not provide for a specific network, just a gigabit switch with vlan to separate public / private network for Ceph OSD and interface bonding for file server.
The system is currently used everyday since more than one year. And it works perfectly.
Installation
Here is some detail of the installation (from what I remember or I noted):
Ceph Cluster
The current configuration is running on Ceph Cuttlefish (v0.61) and Debian Wheezy. (Installation made in June 2013.)
Debian install and partitionning
The operating system is installed on the SSD with 3 others partitions for osd journal.
$ apt-get install vim sudo sysstat ntp smartmontools
$ vim /etc/default/smartmontools
$ vim /etc/smartd.conf
Kernel upgrade
The use of the kernel version 3.12 available in backports seems improve memory footprint on the osd node.
$ echo "deb http://ftp.fr.debian.org/debian wheezy-backports main" >> /etc/apt/sources.list
$ apt-get install -t wheezy-backports linux-image-3.12-0.bpo.1-amd64
Ceph Installation
( Based on the official documentation: http://ceph.com/docs/master/start/ )
On each server create a ceph user
$ useradd -d /home/ceph -m ceph
$ passwd ceph
$ vim [[/etc/hosts]]
192.168.0.1 store-b1-01
192.168.0.2 store-b1-02
192.168.0.3 store-b1-03
192.168.0.4 store-b1-04
192.168.0.5 store-b1-05
$ echo "ceph ALL = (root) NOPASSWD:ALL" | sudo tee /etc/sudoers.d/ceph
$ chmod 0440 /etc/sudoers.d/ceph
On store-b1-01 (deployment server)
Create a new key for ssh authentication : $ ssh-keygen
$ cluster="store-b1-01 store-b1-02 store-b1-03 store-b1-04 store-b1-05"
$ for i in $cluster; do
ssh-copy-id ceph@$i
done
$ vim /root/.ssh/config
Host store*
User ceph
Install ceph-deploy and its dependencies
$ wget -q -O- 'https://ceph.com/git/?p=ceph.git;a=blob_plain;f=keys/release.asc' | sudo apt-key add -
$ echo deb http://eu.ceph.com/debian-cuttlefish/ $(lsb_release -sc) main | sudo tee /etc/apt/sources.list.d/ceph.list
$ apt-get update
$ apt-get install python-pkg-resources python-setuptools ceph-deploy collectd
$ curl http://python-distribute.org/distribute_setup.py | python
$ easy_install pushy
Install ceph on cluster
$ ceph-deploy install $cluster
$ ceph-deploy new store-b1-01 store-b1-02 store-b1-03
$ vim ceph.conf
$ ceph-deploy mon create store-b1-01 store-b1-02 store-b1-03
Cluster deployment
$ ceph-deploy gatherkeys store-b1-01
$ ceph-deploy osd create \
store-b1-01:/dev/sdb:/dev/sda5 \
store-b1-01:/dev/sdc:/dev/sda6 \
store-b1-01:/dev/sdd:/dev/sda7 \
store-b1-02:/dev/sdb:/dev/sda5 \
store-b1-02:/dev/sdc:/dev/sda6 \
store-b1-02:/dev/sdd:/dev/sda7 \
store-b1-03:/dev/sdb:/dev/sda5 \
store-b1-03:/dev/sdc:/dev/sda6 \
store-b1-03:/dev/sdd:/dev/sda7 \
store-b1-04:/dev/sdb:/dev/sda5 \
store-b1-04:/dev/sdc:/dev/sda6 \
store-b1-04:/dev/sdd:/dev/sda7 \
store-b1-05:/dev/sdb:/dev/sda5 \
store-b1-05:/dev/sdc:/dev/sda6 \
store-b1-05:/dev/sdd:/dev/sda7
Add in fstab:
/dev/sdb1 /var/lib/ceph/osd/ceph-0 xfs inode64,noatime 0 0
/dev/sdc1 /var/lib/ceph/osd/ceph-1 xfs inode64,noatime 0 0
/dev/sdd1 /var/lib/ceph/osd/ceph-2 xfs inode64,noatime 0 0
One can check that all osd have been created, and check the cluster status : $ ceph osd tree
# id weight type name up/down reweight
-1 41.23 root default
-8 41.23 datacenter DC1
-7 41.23 rack b1
-2 8.24 host store-b1-01
0 2.65 osd.0 up 1
1 2.65 osd.1 up 1
2 2.65 osd.2 up 1
-3 8.24 host store-b1-02
3 2.65 osd.3 up 1
4 2.65 osd.4 up 1
5 2.65 osd.5 up 1
-4 8.24 host store-b1-03
6 2.65 osd.6 up 1
7 2.65 osd.7 up 1
8 2.65 osd.8 up 1
-5 8.24 host store-b1-04
9 2.65 osd.9 up 1
10 2.65 osd.10 up 1
11 2.65 osd.11 up 1
-6 8.24 host store-b1-05
12 2.65 osd.12 up 1
13 2.65 osd.13 up 1
14 2.65 osd.14 up 1
File Server
Debian interface bonding
$ apt-get install ifenslave
$ vim /etc/network/interface
auto bond0
iface bond0 inet static
address 192.168.0.12
netmask 255.255.0.0
gateway 192.168.0.1
slaves eth0 eth1
bond-mode 802.3ad
$ echo "alias bond0 bonding
options bonding mode=4 miimon=100 lacp_rate=1" > vim /etc/modprobe.d/bonding.conf
$ echo "bonding" >> /etc/modules
Kernel Version
The kernel version is important for using KRBD. I recommend to use at least kernel 3.10.26 or later.
$ apt-get install debconf-utils dpkg-dev debhelper build-essential kernel-package libncurses5-dev
$ cd /usr/src/
$ wget http://www.kernel.org/pub/linux/kernel/v3.0/linux-3.6.11.tar.bz2
$ tar xjf linux-3.6.11.tar.bz2
RBD
Create rbd volume (Format 1) :
$ rbd create datashare/share1 --image-format=1 --size=1048576
$ mkdir /share1
$ echo "/dev/rbd/datashare/share1 /share1 xfs _netdev,barrier=0,nodiratime 0 0" >> /etc/fstab
EnhanceIO
The choice of cache mechanism is focused on "EnhanceIO" because it allows to enable or disable cache while a source volume is being used. This is particularly useful when we want to resize a volume without interrupting service.
Build EnhanceIO :
$ apt-get install build-essential dkms
$ git clone https://github.com/stec-inc/EnhanceIO.git
$ cd EnhanceIO/
$ wget http://ftp.de.debian.org/debian/pool/main/e/enhanceio/enhanceio_0+git20130620-3.debian.tar.xz
$ tar xJf enhanceio_0+git20130620-3.debian.tar.xz
$ dpkg-buildpackage -rfakeroot -b
$ dpkg -i ../*.deb
Create cache :
For exemple in write-though : (/dev/sdb2 is a local partition dedicate for cache)
$ eio_cli create -d /dev/rbd1 -s /dev/sdb2 -p lru -m wt -b 4096 -c share1
If you want to use write-back cache, you can protect the file system to mount before the cache by using a symbolic link in the udev script. ( https://github.com/ksperis/EnhanceIO/commit/954e167fdb580d514747512ce2bd1c9c29a77418 )
Samba
Packages installation
$ echo "deb http://ftp.sernet.de/pub/samba/3.6/debian wheezy main" >> /etc/apt/sources.list
$ apt-get update
$ apt-get install sernet-samba sernet-winbind xfsprogs krb5-user acl attr
Update startup script
$ vim /etc/init.d/samba
# Should-Start: slapd cups rbdmap
# Should-Stop: slapd cups rbdmap
$ insserv -d samba
Configure and join the domain ( https://help.ubuntu.com/community/ActiveDirectoryWinbindHowto )
$ vi /etc/krb5.conf
...
$ kinit Administrator@AD.MYDOMAIN.COM
$ vim /etc/samba/smb.conf
[global]
workgroup = MYDOMAIN
realm = AD.MYDOMAIN.COM
netbios name = MYNAS
wins server = 192.168.0.4
server string = %h server
dns proxy = no
log file = /var/log/samba/log.%m
log level = 1
max log size = 1000
syslog = 0
panic action = /usr/share/samba/panic-action %d
security = ADS
winbind separator = +
client use spnego = yes
winbind use default domain = yes
domain master = no
local master = no
preferred master = no
encrypt passwords = true
passdb backend = tdbsam
obey pam restrictions = yes
unix password sync = yes
passwd program = /usr/bin/passwd %u
passwd chat = *Enter\snew\s*\spassword:* %n\n *Retype\snew\s*\spassword:* %n\n *password\supdated\ssuccessfully* .
pam password change = yes
idmap uid = 10000-20000
idmap gid = 10000-20000
template shell = /bin/bash
template homedir = /share4/home/%D/%U
winbind enum groups = yes
winbind enum users = yes
map acl inherit = yes
vfs objects = acl_xattr recycle shadow_copy2
recycle:repository =.recycle/%u
recycle:keeptree = yes
recycle:exclude = *.tmp
recycle:touch = yes
shadow:snapdir = .snapshots
shadow:sort = desc
ea support = yes
map hidden = no
map system = no
map archive = no
map readonly = no
store dos attributes = yes
load printers = no
printing=bsd
printcap name = /dev/null
disable spoolss = yes
guest account = invité
map to guest = bad user
$================================================================
[share0]
comment = My first share
path = /share0
writable = yes
valid users = @"MYDOMAIN+Domain Admins" "MYDOMAIN+laurent"
[share1]
comment = Other share
path = /share1
writable = yes
valid users = @"MYDOMAIN+Domain Admins" "MYDOMAIN+laurent"
....
$ /etc/init.d/samba restart
$ net join -U Administrator
$ wbinfo -u
$ wbinfo -g
$ vi /etc/nsswitch.conf
passwd: compat winbind
group: compat winbind
Virtual Shadow Copy
Using this script : https://github.com/ksperis/autosnap-rbd-shadow-copy
TimeMachine Backup
Fisrt, create rbd timemachine and mount to /mnt/timemachine with noatime and uquota if you want to use per user quota (Do not add to the autosnap script.)
Install avahi
$ apt-get install avahi-daemon avahi-utils
$ vim /etc/avahi/services/smb.service
<?xml version="1.0" standalone='no'?>
<!DOCTYPE service-group SYSTEM "avahi-service.dtd">
<service-group>
<name replace-wildcards="yes">%h (File Server)</name>
<service>
<type>_smb._tcp</type>
<port>445</port>
</service>
<service>
<type>_device-info._tcp</type>
<port>0</port>
<txt-record>model=RackMac</txt-record>
</service>
</service-group>
$ vim /etc/avahi/services/timemachine.service
<?xml version="1.0" standalone="no"?>
<!DOCTYPE service-group SYSTEM "avahi-service.dtd">
<service-group>
<name replace-wildcards="yes">%h (Time Machine)</name>
<service>
<type>_afpovertcp._tcp</type>
<port>548</port>
</service>
<service>
<type>_device-info._tcp</type>
<port>0</port>
<txt-record>model=TimeCapsule</txt-record>
</service>
<service>
<type>_adisk._tcp</type>
<port>9</port>
<txt-record>sys=waMA=00:1d:09:63:87:e0,adVF=0x100</txt-record>
<txt-record>dk0=adVF=0x83,adVN=TimeMachine</txt-record>
</service>
</service-group>
Install netatalk and configure like this :
$ apt-get install netatalk
$ vim /etc/netatalk/afpd.conf
- -tcp -noddp -nozeroconf -uamlist uams_dhx.so,uams_dhx2.so -nosavepassword -setuplog "default log_info /var/log/afpd.log"
$ vim /etc/netatalk/AppleVolumes.default (Remove home directory + Add :)
/mnt/timemachine/ "TimeMachine" cnidscheme:dbd options:usedots,upriv,tm allow:@"MYDOMAIN+Domain Users"
$ vim /etc/pam.d/netatalk
auth required pam_winbind.so
account required pam_winbind.so
session required pam_unix.so
Setting quota for a user : (Do not use soft limits, because it will not be recognized by timemachine.)
$ xfs_quota -x -c 'limit bhard=1024g user1' /mnt/timemachine
Benchmark
( For sequential IO, bandwidth is limited by the network card on the client side. )