2015년 10월 19일 월요일

How to Configure High Availability Feature in XenServer





Instructions


Complete the following procedure to enable and disable HA on your XenServer pool:
  1. To enable HA for your XenServer pool (with three or more hosts), select the Pool Name/Resource Icon:
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  2. Right-click the Pool Name/Resource icon and select High Availability...
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  3. Alternatively, with the Pool Name/Resource icon highlighted, select the HA tab and select Configure HA…
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  4. The Configure HA dialog box appears. Read the requirements before selecting Next.
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  5. The configuration wizard scans the pool for a Hearbeat SR. If no suitable SR is found, the wizard will exit and one must establish the High Availability Heartbeat Storage Repository (per requirements).
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  6. When an appropriate SR is found, select it and press Next.
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  7. The configuration will present all VMs that are currently in the pool. It is from this configuration dialog will allow one or multiple VMs to be selected as to specify:
    1. The HA restart priority that defines if VMs should be – with enough resources available in the pool – Restarted, Restarted if Possible, and Do Not Restart
    2. The Restart Order - 0 being the highest - that specifies the priority of a VM (or VMs) to be started under a fail-over condition
    3. The Attempt to start next VM delay that specifies how much time should pass before starting the next priority-based VM (or group of VMs).  This is to ensure pool resources are not overwhelmed when recovering from a fail-over condition
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  1. When the HA conditions are specified, selecting Next presents a review of the HA config. Pressing Finish confirms the configuration and apply it to the pool.
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  2. With the successful application of the HA configuration across the pool, the HA tab should show the following:
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  3. To begin the process of disabling HA for your XenServer pool (with three or more hosts), select the Pool Name/Resource icon:
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  4. With the Pool Name/Resource icon highlighted, select the HA tab and select Disable HA…
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  5. When prompted to disable HA, select YES.
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    The HA is disabled across the pool (for each member).

2015년 10월 16일 금요일

How to set up management access for the N4000 switch


Table of Contents
1.    Setting a management IP address
2.    Setting Login access on the switch
3.    Choosing Telnet, HTTP, SSH, or HTTPS for management
4.    Saving configuration


Article description: This article explains how to set up different management options for the N series switches, and explains the recommended settings


Setting a management IP address
A reachable IP address is needed to manage the switch when not using a serial connection. To set an IP address, input the following commands.
This example uses VLAN 1, the default VLAN, and the IP 192.168.0.250 /24.
console>enable
console#configure
console(config)#interface vlan 1
console(config-if)#ip address 192.168.0.250 255.255.255.0
Note: On the N3000 and N4000 switches there is an out of band port that can be used for managing the switch.
Here is the same example but using the out-of-band (OOB) interface.
console(config)#interface out-of-band
console(config-if)#ip address 192.168.0.250 255.255.255.0
It is recommended to use the OOB interface to manage your switch when available. The OOB interface is separate from the switching silicon,
and reaches the CPU directly. If the production network is experiencing issues, you can still reach the switch through the OOB interface.
Note: Plug the OOB interface into a separate management network, and do not plug it back into the inbound ports on the switch.
It is recommended when using a VLAN to manage your network, to make a separate VLAN just for management.
This separates management traffic from your data traffic. This not only helps with performance, but also slightly increases security.
You can manage the switch through any reachable VLAN IP address.
If managing the switch from an external network, you must assign the switch a Default Gateway it can use to reach other networks.
The following command uses 192.168.0.1 as the Default Gateway address.
console(config)#ip default-gateway 192.168.0.1


Setting login access on the switch.
To manage the switch you will need a username and password. To manage the switch via telnet or SSH, you will require an enable password. Input the following commands to configure login access. This is an example with the username as Dell, and password as P@$$w0rd. The enable password example uses ENP@$$w0rd. These are just examples and you should use more complicated, hard to guess credentials to secure your switch.
console>enable
console#configure
console(config)#username Dell password P@$$w0rd level 15

console(config)#enable password ENP@$$w0rd
Note: You may make multiple users on the switch, as well as different levels/privilege level of access. 0 is no access, 1 in read only, and 15 is read and write.

How to use iSCSI Targets on a Windows Server

How to use iSCSI Targets on a Windows Server

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Overview

The business-level Synology NAS servers are Microsoft® Windows certified, which means by using the iSCSI Target Service, a Synology NAS seamlessly acts as dedicated storage server to provide iSCSI Target storage for your Hyper-V environment, which will be seen virtually as a local hard drive for as many clients as need be; only they are all stored in a centralized Synology server. Advanced management functions such as Thin Provisioning, iSCSI LUN Backup, MC/S (Multiple Connections per Session) and MPIO (Multipath I/O) are available on Synology NAS to strengthen the usability and stability of a network storage environment. As fully compliant with SPC-3 PR standard, Synology NAS supports Microsoft Windows® Server Failover Clustering as well.
This article will guide you through the process of setting up iSCSI target connection from a Windows Server to your Synology NAS.
What is iSCSI?
iSCSI is an Internet Protocol based storage networking standard for linking data storage facilities. By carrying SCSI commands over IP networks, iSCSI can facilitate data transfers over local area networks (LANs), wide area networks (WANs), or the Internet. Through iSCSI, the space on storage server will be regarded as local disks by client's operation system. In reality, all data transferred to the disk are actually transferred over network to the storage server.
What is iSCSI Target and LUN?
In SCSI terminology, a LUN (logical unit number) represents an individually addressable (logical) SCSI device that is part of a physical SCSI device (called "Target"). An iSCSI environment emulates the connection to a SCSI hard disk. An iSCSI Target is like a connection interface, and LUNs are essentially numbered disk drives. When an iSCSI Target is connected by an iSCSI initiator (a client), all the LUNs mapped to the iSCSI Target are virtually attached to the client's operation system. Therefore, Initiators can establish and manage file systems on iSCSI LUNs, as they would a raw SCSI or IDE hard drive.

Contents

  1. Before You Start
  2. Create an iSCSI Target
  3. Format iSCSI Target for Use on Windows


1. Before You Start

This article assumes you have performed the following tasks:
  • Hardware installation for Synology NAS.
  • Create iSCSI LUNs and Targets on your Synology NAS.
After the setting above is finished,  you can refer to this article to know how to connect your iSCSI target with Multipath (MPIO).
Refer to Quick Installation Guide for more information about hardware and software installation. You can also see Synology NAS User's Guide (available at Synology's Download Center) for a general idea about topics related to this article.

2. Create an iSCSI Target

This section will guide you through the process of setting up an iSCSI target on a Windows Server.
  1. Open iSCSI Initiator in Windows under Control Panel > Administrative tools.
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  3. Go to Discovery tab and click on Discover Portal.
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  5. Enter the IP Address or the DNS Name of the Synology NAS, which is hosting the iSCSI Target, then click on OK.
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  7. Go to Targets tab.
  8. Select the desired iSCSI target.
  9. Click on Connect.
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  11. Click on OK if no advanced options are enabled on the iSCSI target on the Synology NAS.
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  13. Click on Advanced button if CHAP or any of the Advanced settings are enabled on the iSCSI Target on the Synology NAS.
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  15. Enter the name for CHAP.
  16. Enter the target secret for CHAP.
  17. Click on OK.
  18. The iSCSI target is now connected to the Windows PC.
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3. Format iSCSI Target for Use on Windows

After an iSCSI Target has been connected on a Windows computer, it will have to be formatted before it can be used.
  1. Open Computer Management under Control Panel > Administrative tools.
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  3. Select Disk Management on the left panel. Right click on the iSCSI Target (Disk1) and choose Online.
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  5. Right click on the iSCSI Target (Disk1) again and choose Initialize Disk.
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  7. A prompt will be displayed to initialize the newly added virtual drive. Please select a partition style most appropriate for the disk to be used then click on OK.
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  9. After the disk has been initialized, right click on the new disk (indicated by the black field), and select New Simple Volume.
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  11. Proceed forward with the Simple Volume Wizard.
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  13. Specify the volume size to use for the new hard drive, then click on Next.
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  15. Assign a drive letter for the new hard drive then click on Next.
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  17. Now your Windows Server has an additional drive E: created by Synology iSCSI target.
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Note:
If you want to use Multipath I/O (MPIO) for the iSCSI targets on your Synology NAS, please do the following first:
  1. Go to Storage Manager > iSCSI Target.
  2. Find the desired iSCSI target, and click Edit > Advanced.
  3. Tick Allow multiple sessions from one or more iSCSI initiators.
  4. Click OK.

Linux CPU Info

Linux CPU Info


# cat /proc/cpuinfo

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