ZFS is a combined file system and logical volume manager designed by Oracle/Sun Microsystems. The features of ZFS include support for high storage capacities, integration of the concepts of filesystem and volume management, snapshots and copy-on-write clones, continuous integrity checking and automatic repair, RAID-Z and native NFSv4 ACLs.
This ZFS guide provides an overview of ZFS and its administration commands that will be helpful for beginners.
ZFS Filesystem : ZFS offers a POSIX-compliant file system interface to the Solaris/OpenSolaris operating system. ZFS file systems must be built in one and only one storage pool, but a storage pool may have more than one defined file system. ZFS file systems are managed & mounted through /etc/vfstab file. The common way to mount a ZFS file system is to simply define it against a pool. All defined ZFS file systems automatically mount at boot time unless otherwise configured.Here are the basic commands for getting started with ZFS.
Creating Storage pool using “zpool create” :
bash-3.00# zpool create demovol raidz c2t1d0 c2t2d0 bash-3.00# zpool status pool: demovol state: ONLINE scrub: none requested config:
NAME STATE READ WRITE CKSUM demovol ONLINE 0 0 0 raidz1 ONLINE 0 0 0 c2t1d0 ONLINE 0 0 0 c2t2d0 ONLINE 0 0 0
errors: No known data errors bash-3.00#
“zfs list” will give the details of the pool and other zfs filesytems.
bash-3.00# zfs list NAME USED AVAIL REFER MOUNTPOINT demovol 1.00G 900G 38.1K /demovol bash-3.00#
Creating File Systems : “zfs create” is used to create zfs filesytem.
bash-3.00# zfs create demovol/testing bash-3.00# zfs list NAME USED AVAIL REFER MOUNTPOINT demovol 1.00G 900G 38.1K /demovol demovol/testing 32.6K 900G 32.6K /demovol/testing bash-3.00#
bash-3.00# ls /dev/zvol/dsk/demovol — This should show you the disk file.
Setting Quota for the filesytem : Until Quota is set, the filesytem shows the total available space of the containter zfs pool.
bash-3.00# zfs set quota=10G emspool3/testing bash-3.00# zfs list NAME USED AVAIL REFER MOUNTPOINT demovol 1.00G 900G 39.9K /demovol demovol/testing 32.6K 10.0G 32.6K /demovol/testing
Creating a snapshot :
bash-3.00# zfs snapshot demovol/[email protected] bash-3.00# zfs list NAME USED AVAIL REFER MOUNTPOINT demovol 1.00G 900G 39.9K /demovol demovol/testing 32.6K 10.0G 32.6K /demovol/testing demovol/[email protected] 0 – 32.6K - bash-3.00#
Get all properties of a ZFS filesytem :
bash-3.00# zfs get all demovol/testing NAME PROPERTY VALUE SOURCE demovol/testing type filesystem - demovol/testing creation Mon Feb 9 9:05 2009 - demovol/testing used 32.6K - demovol/testing available 10.0G - demovol/testing referenced 32.6K - demovol/testing compressratio 1.00x - demovol/testing mounted yes - demovol/testing quota 10G local demovol/testing reservation none default demovol/testing recordsize 128K default demovol/testing mountpoint /demovol/testing default ..
Cloning a ZFS filesystem from a snapshot :
bash-3.00# zfs clone demovol/[email protected] demovol/clone22 bash-3.00# zfs list NAME USED AVAIL REFER MOUNTPOINT demovol 1.00G 900G 39.9K /demovol demovol/clone22 0 900G 32.6K /demovol/clone22 demovol/testing 32.6K 10.0G 32.6K /demovol/testing demovol/[email protected] 0 – 32.6K - bash-3.00#
Performance IO Monitoring the ZFS storage pool:
bash-3.00# zpool iostat 1 capacity operations bandwidth pool used avail read write read write ———- —– —– —– —– —– —– demovol 4.95M 900G 0 0 0 35 demovol 4.95M 900G 0 0 0 0 demovol 4.95M 900G 0 0 0 0 demovol 4.95M 900G 0 0 0 0
Linux network Bonding is creation of a single bonded interface by combining 2 or more Ethernet interfaces. This helps in high availability of your network interface and offers performance improvement. Bonding is same as port trunking or teaming.
Steps for bonding in Oracle Enterprise Linux and Redhat Enterprise Linux are as follows..
Create the file ifcfg-bond0 with the IP address, netmask and gateway. Shown below is my test bonding config file.
$ cat /etc/sysconfig/network-scripts/ifcfg-bond0
Modify eth0, eth1 and eth2 configuration as shown below. Comment out, or remove the ip address, netmask, gateway and hardware address from each one of these files, since settings should only come from the ifcfg-bond0 file above. Make sure you add the MASTER and SLAVE configuration in these files.
$ cat /etc/sysconfig/network-scripts/ifcfg-eth0
# Settings for Bond
$ cat /etc/sysconfig/network-scripts/ifcfg-eth1
# Settings for bonding
$ cat /etc/sysconfig/network-scripts/ifcfg-eth2
Set the parameters for bond0 bonding kernel module. Select the network bonding mode based on you need, documented at http://unixfoo.blogspot.com/2008/02/network-bonding-part-ii-modes-of.html. The modes are
- mode=0 (Balance Round Robin)
- mode=1 (Active backup)
- mode=2 (Balance XOR)
- mode=3 (Broadcast)
- mode=4 (802.3ad)
- mode=5 (Balance TLB)
- mode=6 (Balance ALB)
Add the following lines to /etc/modprobe.conf
# bonding commands
alias bond0 bonding
options bond0 mode=1 miimon=100
Load the bond driver module from the command prompt.
$ modprobe bonding
Restart the network, or restart the computer.
$ service network restart # Or restart computer
When the machine boots up check the proc settings.
$ cat /proc/net/bonding/bond0
Ethernet Channel Bonding Driver: v3.0.2 (March 23, 2006)
Bonding Mode: adaptive load balancing
Primary Slave: None
Currently Active Slave: eth2
MII Status: up
MII Polling Interval (ms): 100
Up Delay (ms): 0
Down Delay (ms): 0
Slave Interface: eth2
MII Status: up
Link Failure Count: 0
Permanent HW addr: 00:13:72:80: 62:f0
Look at ifconfig -a and check that your bond0 interface is active. You are done!. For more details on the different modes of bonding, please refer to unixfoo’s modes of bonding.
To verify whether the failover bonding works..
- Do an ifdown eth0 and check /proc/net/bonding/bond0 and check the “Current Active slave”.
- Do a continuous ping to the bond0 ipaddress from a different machine and do a ifdown the active interface. The ping should not break.
- Written by: cloudibee
- Category: Uncategorized
- Published: August 27, 2009
- Reduce backup windows versus traditional tape-based backup
- Media cost savings
- No backup/recovery failures due to media errors
- Simple and Fast recovery of corrupted or destroyed data
Snapvault consists of major two entities – snapvault clients and a snapvault storage server. A snapvault client (Netapp filers and unix/windows servers) is the system whose data should be backed-up. The SnapVault server is a Netapp filer – which gets the data from clients and backs up data. For Server to Netapp Snapvault, we need to install Open System Snapvault client software provided by Netapp, on the servers. Using the snapvault agent software, the Snapvault server can pull and backup data on to the backup qtrees. SnapVault protects data on a client system by maintaining a number of read-only versions (snapshots) of that data on a SnapVault filer. The replicated data on the snapvault server system can be accessed via NFS or CIFS. The client systems can restore entire directories or single files directly from the snapvault filer. Snapvault requires primary and secondary license.
How snapvault works?
When snapvault is setup, initially a complete copy of the data set is pulled across the network to the SnapVault filer. This initial or baseline, transfer may take some time to complete, because it is duplicating the entire source data set on the server – much like a level-zero backup to tape. Each subsequent backup transfers only the data blocks that has changed since the previous backup. When the initial full backup is performed, the SnapVault filer stores the data on a qtree and creates a snapshot image of the volume for the data that is to be backed up. SnapVault creates a new Snapshot copy with every transfer, and allows retention of a large number of copies according to a schedule configured by the backup administrator. Each copy consumes an amount of disk space proportional to the differences between it and the previous copy.
Snapvault commands :
Initial step to setup Snapvault backup between filers is to install snapvault license and enable snapvault on all the source and destination filers.
Source filer – filer1
filer1> license add XXXXX
filer1> options snapvault.enable on
filer1> options snapvault.access host=filer2
Destination filer – filer2
filer2> license add XXXXX
filer2> options snapvault.enable on
filer2> options snapvault.access host=filer1
Consider filer2:/vol/snapvault_volume as the snapvault destination volume, where all backups are done. The source data is filer1:/vol/datasource/qtree1. As we have to manage all the backups on the destination filer (filer2) using snapvault – manually disable scheduled snapshots on the destination volumes. The snapshots will be managed by Snapvault. Disabling Netapp scheduled snapshots, with below command.
filer2> snap sched snapvault_volume 0 0 0
Creating Initial backup: Initiate the initial baseline data transfer (the first full backup) of the data from source to destination before scheduling snapvault backups. On the destination filer execute the below commands to initiate the base-line transfer. The time taken to complete depends upon the size of data on the source qtree and the network bandwidth. Check “snapvault status” on source/destination filers for monitoring the base-line transfer progress.
filer2> snapvault start -S filer1:/vol/datasource/qtree1 filer2:/vol/snapvault_volume/qtree1
Creating backup schedules: Once the initial base-line transfer is completed, snapvault schedules have to be created for incremental backups. The retention period of the backup depends on the schedule created. The snapshot name should be prefixed with “sv_”. The schedule is in the form of “[@][@]”.
On source filer:
For example, let us create the schedules on source as below – 2 hourly, 2 daily and 2 weekly snapvault . These snapshot copies on the source enables administrators to recover directly from source filer without accessing any copies on the destination. This enables more rapid restores. However, it is not necessary to retain a large number of copies on the primary; higher retention levels are configured on the secondary. The commands below shows how to create hourly, daily & weekly snapvault snapshots.
filer1> snapvault snap sched datasource sv_hourly [email protected]
filer1> snapvault snap sched datasource sv_daily [email protected]
filer1> snapvault snap sched datasource sv_weekly [email protected]@sun
On snapvault filer:
Based on the retention period of the backups you need, the snapvault schedules on the destination should be done. Here, the sv_hourly schedule checks all source qtrees once per hour for a new snapshot copy called sv_hourly.0. If it finds such a copy, it updates the SnapVault qtrees with new data from the primary and then takes a Snapshot copy on the destination volume, called sv_hourly.0. If you don’t use the -x option, the secondary does not contact the primary and transfer the Snapshot copy. It just creates a snapshot copy of the destination volume.
filer2> snapvault snap sched -x snapvault_volume sv_hourly [email protected]
filer2> snapvault snap sched -x snapvault_volume sv_daily [email protected]@sun-fri
filer2> snapvault snap sched -x snapvault_volume sv_weekly [email protected]@sun
To check the snapvault status, use the command “snapvault status” either on source or destination filer. And to see the backups, do a “snap list” on the destination volume – that will give you all the backup copies, time of creation etc.
Restoring data : Restoring data is as simple as that, you have to mount the snapvault destination volume through NFS or CIFS and copy the required data from the backup snapshot.
You can also try Netapp Protection manager to manage the snapvault backups either from OSSV or from Netapp primary storage. Protection manager is based on Netapp Operations manager (aka Netapp DFM). It is a client based UI, with which you connect to the Ops Manager and protect your storages.
To read how to tune the performance & speed of the netapp snapmirror or snapvault replication transfers and adjust the transfer bandwidth , go to Tuning Snapmirror & Snapvault replication data transfer speed
Static routes will be added usually through “route add” command. The drawback of ‘route’ command is that, when Linux reboots it will forget static routes. But to make it persistent across reboots, you have to add it to /etc/sysconfig/network-scripts/route- .
To add static route using “route add”:
# route add -net 192.168.100.0 netmask 255.255.255.0 gw 192.168.10.1 dev eth0
Adding Persistent static route:
You need to edit /etc/sysconfig/network-scripts/route-eth0 file to define static routes for eth0 interface.
Save and close the file. Restart networking:
# service network restart
Verify new routing table:
# route –n
# netstat –nr