https://www.ibm.com/developerworks/community/blogs/9e696bfa-94af-4f5a-ab50-c955cca76fd0/entry/how_to_choose_best_storage_device_for_you_on_softlayer?lang=en
How to choose best storage device for you on softlayerHow to choose best storage device for you on softlayer
Cui Li quan
Zi Xuan Zhan
Rong Zhao (zha
1. What’s storage type you can choose on Softlayer
Softlayer provide several kind of storage and you have a choice of local disk, SAN disk, iscsi SAN disk, NAS, object storage to satisfy your all kinds of requirement.
Below table compare different storages from raid level, I/O rate, price, maximum size which softlayer provides perspective, give you an brief impression for those storages.
Note: All the I/O Rate isn't official data, just tested by me, just for your reference
Table 1
2. How to choose different storage2.1 Local Disk
You can choose local disk when you provision cci intance if you need more higher I/O speed, but no need too many disk requirement
How many size the cci instance with local disk?
As show in the table 1, the first disk is 25GB or 100GB, the secondary disk is 25GB to 300GB, so the maximum disk can be provided is 400GB
2.2 SAN Disk
You can choose SAN disk if you need more disk space, A virtual server cannot be ordered with both local disks and SAN disks, your disk selection to contain only local disks or only SAN disks.
For the CCI Instance with SAN disk, virtual server have five virtual disk, the first disk is 25GB or 100GB, for second disk to fifth disk, you can choose 10GB to 2TB for each virtual disk, so the maximum disk is 8TB
2.3 Migrate to SAN based virtual server from Local Disk
We have know that virtual server with local disk, which only have maximum 400GB disk, with your business grow up, you run out of all the disk space, what should you do? Provisioning a refresh cci instance, then install and deploy your applications, all from the beginning? The answer is NO.
Softlayer can migrate the virtual server with local disk to SAN based virtual server.
Find the cci instance from Softlayer UI http
If you use http
2.4 iscsi SAN disk
Iscsi SAN disk is a good supplementary if you need more than 8TB san disk, you can attach a new iscsi SAN disk to the cci instance, the maximum size of iscsi SAN disk is 3TB.
Iscsi also provides replication and snapshot function, you can replicate your data which saved in iscsi SAN disk to another data center, ࠄThe replication feature runs on a schedule and is not an immediate process at this time.
2.5 NAS Storage
SoftLayer offers Network Attached Storage (NAS) as one of our basic storage solutions for users looking for quick, cost-efficient backup for their SoftLayer devices. NAS is compatible with each of our offered operating systems and may also be used via File Transfer Protocol (FTP) with both Parallels Plesk Panel and cPanel&WHM. NAS and FTP storage is billed monthly to users and is available in a variety of storage sizes. Users interact with their NAS and FTP storage primarily within the command line or terminal within the OS or through point-and-click interaction for control panels. Within the Customer Portal, NAS details and usage can be used, but the service itself may not be manipulated outside of the command line, kernel or control panel.
3. Storage Usage Scenario3.1 Create shared disk using iscsi SAN disk
This section will introduce how to connect Multiple Servers to a Single iSCSI LUN
The filesystem you use on the iSCSI mount must be cluster ware, for example, ocfs or gpfs, or other supported cluster ware
Your applications must also be cluster aware which use this filesystem.
We will introduce IBM cluster software GPFS, or ocfs, you can refer to http
Please find the device file using below command after you configure iscsi-initiator to connect to a iscsi LUN.
find /sys
You maybe find a iscsi disk /dev/sda
Extract gpfs rpm packages
export DISPLAY=Your workstation IP:0.0
./g
cd /usr/lpp/mmfs/4.1
rpm -ivh gpfs*.x86_64.rpm rpm -ivh gpfs*.x86_64.rpm
Check the GPFS rpms installed on each node as shown
Generate ssh keypair using ssh-keygen -t rsa -b 2048 -C "GPFS KEYPAIR" -f /root/.ssh/id_rsa -N '', then add /roo
Nodes Properties:
manager or client, quorum or nonquorum [roo Clst Clst [roo Clst Clst Accept License /usr Note: if some nodes as client, the command as below: /usr
-r /usr/bin/rsh -R /usr/bin/rcp
means manage cluster using rsh,rcp mode
[roo
mmcrnsd: Processing disk sda mmcrnsd: Propagating the cluster configuration data to all affected nodes. This is an asynchronous process.
3.2 Using File Storage NAS to backup DR data
Softlayer provide a kind of File storage, it’s NAS, NAS storage can cross different data center, for example, you can mount NAS storage which located at Amsterdam DC to the VM in Dallas 5, so you can backup or archive some Disaster Recovery data from one DC to another DC.
NAS storage is monthly charged storage, it’s a little expensive storage, you can order 20GB to 2TB storage.
How to connect to NAS Storage
Before you use NAS storage, you must install cifs-utils samba-client samba.
Install Instruction:
CentOS:
yum install samba3x samba3x-client
RHEL:
yum install cifs-utils samba-client samba
Three method to mount NAS storage in linux
Mount in Lnux
mount-t cifs //na
Smbmount in Linux
If you have not already done so, create the directory you want the NAS account mapped to
Example:
mkdir /drcopydata
smbmount //na
ftp Access
Example:
ftp nas0
FTP Username: XXXXXXX-X
FTP Password: password
Usually we use the first way Mount in Lnux
Then we use rsync to sync our backup data to NAS Storage
rsync -avzP /drdata/* /drcopydata/ --delete --exclude=logs/
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