NAS HA


Description

The NAS is a file server connected to the network. Its main purpose is to hold all your data in a centralized location available to all your clients.

Pre Requisites

To benefit from the NAS-HA offer, you must:

Own a dedicated server with OVH and have the option “professional use” for servers prior to the 2014 product line.

How to Order

  • First connect to your OVH manager
  • Choose “Network” in the menu on the left
  • Then lick on “NAS
  • Fill-in the following form
_images/products-nas-ha-order.png

Ordering a NAS

  • Select a “data center
  • Select a NAS starting with “NAS-HA

Note

You will be able to create partitions in CIFS or NFS or both. CIFS will allow the partition to be mounted on Linux, Windows and FreeBSD.

  • Select the duration of the subscription.
  • Then click on the “Order” button.
  • Confirm that you have read and accepted terms and conditions and click on “Order
  • To finish, you will be redirected to the purchase order which you can complete to finalize the order.

Usage

Managing Partitions

On a NAS-HA you can create partitions and choose which servers have access to which partitions.

Creating a partition

To create a partition:

  • Connect to your OVH manager
  • Select the “Network” section
  • Select “NAS” in the sub-menu
  • Click on “Create a partition
_images/products-nas-ha-partition.png

Creating a partition

Deleting a partition

To delete a partition:

  • Connect to your OVH manager
  • Select the “Network” section
  • Select “NAS” in the sub-menu
  • Click the cogwheel to the right of the partition and click “Delete
_images/products-nas-ha-rm-partition.png

Delete Partitions

  • Finally, confirm the deletion

Resizing a partition

To resize a partition:

  • Connect to your OVH manager
  • Select the “Network” section
  • Select “NAS” in the sub-menu
  • Click the cogwheel to the right of the partition and select “Resize
_images/products-nas-ha-rm-partition.png

Resizing a partition

  • Do the modifications
_images/products-nas-ha-edit-partition.png

Confirm resizing of the partition

Access management

  • Connect to your OVH manager
  • Select the “Network” section
  • Select “NAS” in the sub-menu
  • Click the cogwheel to the right of the partition and select “Show access
_images/products-nas-ha-rm-partition.png

Manage NAS Access

  • To authorize an access
    • Click on “Add access
    • Select the IP you want to authorize
    • To finish click on “validate
  • To delete an access
    • Click on the icon at the end of line of the IP to unauthorize
    • To finish click on “validate

Mount your NAS

You will be able to access partitions in CIFS or NFS or both, depending on the option you chose during its creation.

NFS

To access you NAS you must have created an access for your IPs by following the Access management section.

To be able to mount the partition you will the following information:

NFS_SERVER_IP:The IP of the NAS (example: 10.16.101.8).
NFS_PATH:The path is /NASNANE/PARTITON (example: /zpool-000YY/mypartitionname)
MOUNT_PATH:This is the path you choose to mount the partition (example: /mnt)
mount -t nfs NFS_SERVER_IP:/NFS_PATH/NFS_PATH /MOUNT_PATH

Note

The name and IP of the NAS can be found in your manager when you click on “About partitions

CIFS

To access you NAS you must have created an access for your IPs by following the Access management section.

To be able to mount the partition you will the following information:

CIFS_SERVER_IP:The IP of the NAS (example: 10.16.101.8)
CIFS_PATH:The path is /NASNANE_PARTITON (example: /zpool-000YY_mypartitionname)
MOUNT_PATH:This is the path you choose to mount the partition (example: /mnt)
MOUN_OPTIONS:Here you can put uid=nobody,gid=nogroup,password=

On Windows

net use z: \\CIFS_SERVER_IP_CIFS_PATH
Check this first

On Linux

mount -t cifs -o MOUNT_OPTIONS //CIFS_SERVER_IP/CIFS_PATH /MOUN_PATH
Check this first

Note

The name and IP of the NAS can be found in your manager when you click on “About partitions

Snapshots

One of the most useful and misunderstood feature of the NAS is the snapshot functionality. Understanding it makes it a wonderful data retention tool, but using it without understanding it can lead to serious problems down the road.

How snapshots works

ZFS uses a copy-on-write transactional object model. All block pointers within the filesystem contain a 256-bit checksum of the target block, which is verified when the block is read. Blocks containing active data are never overwritten in place; instead, a new block is allocated, modified data is written to it, then any metadata blocks referencing it are similarly read, reallocated, and written. To reduce the overhead of this process, multiple updates are grouped into transaction groups, and ZIL (intent log) write cache is used when synchronous write semantics are required. The blocks are arranged in a tree, as are their checksums.

Wikipedia

A visual representation of the copy-on-write model:

_images/products-nas-ha-cow.png

There is two important things to understand from this:

  1. ZFS keeps a copy of the data you delete or modify to allow rollbacks
  2. ZFS also keep track of the IO transactions

Warning

Doing a lot of snapshots can quickly fill up your partitions. Be careful not to fill your partitions above 75%, above that limit ZFS may become unpredictable if it has no place left to save the snapshot(s).

Accessing your snapshots

Snapshots are instant images of the data present on your NAS partitions. At any time, you can access the snapshots to recuperate your data at the time of the snapshot (for example 1 hour ago).

  • To access your snapshots you need to navigate to location in which you mounted the partition (for example /mnt)
  • You should have a .zfs folder which contains a snapshot folder (example: /mnt/.zfs/snapshot)
cd /mnt/.zfs/snapshot
  • Then by listing the files in that folder you should see a list of your snapshots
ls -la /mnt/.zfs/snapshots
total 3
dr-xr-xr-x+ 4 root root 4 16 nov. 13:26 .
dr-xr-xr-x+ 3 root root 3 16 nov. 13:26 ..
drwxr-xr-x+ 5 root root 5 14 fevr. 11:02 2011-04-19
drwxr-xr-x+ 5 root root 5 14 fevr. 11:02 hourly_last

Managing additional snapshots

You can activate or deactivate snapshots by doing the following:

  • Connect to you OVH manager
  • Select the “Network” section
  • Select “NAS” in the sub-menu
  • Click the cogwheel to the right of the partition and select “Snapshot frequency
_images/products-nas-ha-rm-partition.png

Snapshot Frequency

  • Then click on the pencil icon
_images/products-nas-ha-acl1.png

Edit Snapshot Frequency

  • You will be able to select/de-select the snapshots frequency options you need.

Warning

It is strongly recommended to select only one check box at this step, because selecting multiple will fill you partition really fast.

_images/products-nas-ha-acl2.png

Confirm Snapshot Frequency

  • When you are done click on the check mark