Hardware-less VM Storage

StarWind FAQ


Table of Contents

General


General

Q. Both HA nodes and are shown as not synchronized. How can I fix this?

A. After both nodes of the HA cluster were down simultaneously in some cases StarWind is not able to determine which node holds the most recent data. So it blocks all the incoming connections until the synchronization begins to prevent the data corruption. If you know for sure which node was shut down last – choose it as the synchronization source in the drop down menu of the HA device – Synchronization, or mark as synchronized the node with actual data choose from the dropbox by right clicking on the HA device and choosing the corresponding option. The second option assumes automatic start of the synchronization. If you are not sure about it – delete the HA targets from the StarWind Management console, mount HA images as basic targets. Important notice: keep in mind that you just need to find out if the data is consistent, so make sure that any new data won`t be written to the target on this step. Check which node has the most recent data, remove the target and recreate the HA device running the synchronization in appropriate direction.

Table of Contents



Q. When I write the data to the target I'm not able to see it on other client machine which has the same disk connected. Why?

A. Unlike file-level protocols like used in NAS, iSCSI is a block-level protocol. Thus it cannot arbiter read-write access to the iSCSI device connected to multiple servers. Thus, to provide access to one device from multiple servers the device needs to have a clustered file system. 3rd party arbiter SAN management software (DataPlow SFS, MelioFS, MetaSAN etc) should be used for individual client servers. If using vSphere 3rd party management software is not necessary since VMFS is a clustered file system. At the same time Microsoft failover clustering allows to share single storage device between the nodes of the cluster. For instance, Hyper-V failover clustering is achieved by converting the iSCSI storage to a Cluster Shared Volume (CSV).

Table of Contents



Q. How can I change Heartbeat or Synchronization Channel IPs?

A. Click on the corresponding device in the Starwind management console. In the right side window find Replication Node Interface and click on it. In the window that will appear you can edit heartbeat and synchronization channels settings on the fly.

Table of Contents



Q. Why is StarWind not utilizing all the available bandwidth of the network channel?

A. We recommend you to take a look at our special guide on the forum. It describes instructions and tweaks that you may apply to achieve better performance: http://www.starwindsoftware.com/forums/starwind-f5/recommended-tcp-settings-t2293.html. If you still face with low performance even after implementing the appropriate tweaks and checking the hardware please contact our support team: http://starwindsoftware.com/support

Table of Contents



Q. Where can I find the release information and version changelog?

A. This information can be found in our press release section and on the forum:
http://www.starwindsoftware.com/news http://www.starwindsoftware.com/forums/post16541.html#p16541 This information is also included in our newsletter.
Changelog can be found on the forum. It can be also reviewed during StarWind installation process and later as a changelog.txt file in the StarWind installation folder.

Table of Contents



Q. Where can I get latest version of StarWind?

A. You can get it on our customer portal any time! Login here

Table of Contents



Q. What cache is better to use, Write-Back or Write-Through? And what does expiry period mean?

A. We highly recommend using Write-Back caching. Write-Back caching improves write speed and lowers the latency unlike Write-Through caching which improves only the read speed. Cache expiry period is the timeframe data is kept in cache from the moment of the last access till the moment it is flushed to the disk.

Table of Contents



Q. What is heartbeat?

A. Heartbeat is an advanced mechanism which is used to avoid data corruption in case of synchronization channel failure. If data can`t be transferred through the synchronization channel StarWind checks availability of the second node through the alternate network interface, and shuts down secondary node in case of synchronization channel failure.

Table of Contents



Q. How to upgrade our HA to version 8.0 from version 6?

A.
  • 1. To prevent data loss disconnect clients from HA (if it is possible);
  • 2. Run the StarWind v8 installer on the first node;
  • 3. Install the v8 license key in the installation wizard when requested;
  • 4. Wait until StarWind service starts and the synchronization process begins;
  • 5. Wait until the synchronization process is over;
  • 6. Connect the client machines to the first node;
  • 7. Repeat the same step on all the rest StarWind nodes one-by-one.
Please note that Mirror, IBV and Deduplication devices of version 6.x and earlier versions are not fully supported in v8.0! Data from existing Mirror, IBV and Deduplication devices must be migrated to new ImageFile or LSFS devices after installation.

Table of Contents



Q. How can I extend the iSCSI volume on the client machine?

A. In StarWind console choose the device that you want to modify and click on Extending Size of HA (High availability) Device/Image File Size button in the right side window. Then specify disk space that you want to add and click "Finish" button.

Table of Contents



Q. When I create an HA device in the Add Target wizard, there is the "Specify interfaces for synchronization and heartbeat channels" step. Why does the wizard automatically select all IPs located in the same subnetwork when I select only one that I need?

A. We strongly recommend connecting every data link to a dedicated subnetwork (every synchronization channel and heartbeat). When you select one IP, the wizard automatically reserves all IPs in the subnet. This is intended to protect the StarWind users from misconfiguring HA by assigning Heartbeat and Synchronization Channel to the same data link.

Table of Contents



Q. What is the best way to migrate StarWind HA to new hardware?

A. Hardware update does not require downtime. We recommend the following sequence that assumes that Windows, its roles and features are already installed and configured on new Node 1 and Node 2.

To migrate StarWind HA to new hardware:
  • 1. Disconnect old Node 1 targets from all the client servers.
  • 2. In the StarWind Management Console right-click the HA device on old Node 2, and select Replication Manager.
  • 3. In the Replication Manager window remove the replica of HA device. Carry out this procedure for each HA device.
  • 4. Shut down old Node 1.
  • 5. Connect the synchronization links of the old Node 2 to new Node 1 server.
  • 6. Turn Power on new Node 1 with new hardware.
  • 7. Configure the synchronization links between new Node 1 and old Node 2.
  • 8. Install StarWind on new Node 1 and apply the purchased license file to the new installation.
  • 9. In the StarWind Management Console right-click the HA device on old Node 2, and select Replication Manager.
  • 10. In the Replication manager window click the Add Replica button. Follow the Wizard steps to set up the HA device replica on new Node 1. Carry out this procedure for each HA device.
  • Note: It is recommended to add the next device replicas after the previous device has finished to synchronize)
  • 11. After synchronization is finished, connect new Node 1 to the client servers.
  • 12. Disconnect old Node 2 targets from all the client servers.
  • 13. In the StarWind Management Console right-click the HA device on new Node 1, select Replication Manager.
  • 14. In the Replication manager window remove the replica of the HA device. Carry out this procedure for each HA device.
  • 15. Shut down old Node 2.
  • 16. Connect the synchronization links of the new Node 1 to the new Node 2 server.
  • 17. Turn Power on new Node 2.
  • 18. Configure the synchronization links between new Node 2 and new Node 1.
  • 19. Install StarWind on new Node 2 and apply the purchased license file to the new installation.
  • 20. In the StarWind Management Console right-click the HA device on new Node 1, and select Replication Manager.
  • 21. In the Replication manager window click the Add Replica button.
  • 22. Follow the Wizard steps to set up the HA device replica on new Node 2. Carry out this procedure for each HA device.
  • Note: It is recommended to add the next device replicas after the previous device has finished synchronization.
  • 23. Wait for the synchronization to finish ends.
  • 24. After synchronization is finished, connect new Node 2 to the client servers.

Table of Contents



Q. How can I change the cache settings?

A. You can change cache size on fly only for HA. In Starwind console you need to open *.swdsk of corresponding device in your Storage pool and edit the line:
<- cache type="write-back" size="128" units="MB" level="1" -> * by setting required size. Then you need to restart service, wait for synchronization process to end and repeat abovementioned steps on each StarWind node one-by-one.
Note: in HA if you change cache mode it is necessary to change it on all the nodes.
For non-HA it will cause downtime, because you need to turn into offline your storage.
Note: in HA if you change cache mode it is necessary to change cache mode on all nodes. Cache size can be different.

*the line is an example and contain the default settings.

Table of Contents



Q. What is the storage pool?

A. The storage pool is default path to place StarWind virtual disks (LSFS proprietary files, *.img, etc. )

Table of Contents



Q. How can I change default storage pool path?

A.
  • 1. Open StarWind Management Console;
  • 2. Choose the server, where you want to change storage pool path;
  • 3. Click on the "Configuration" tab, then go to the "Advanced Settings";
  • 4. Click on "Modify" that is in the top right corner of StarWind console;
  • 5. In the pop-up window go to the "Storage Pool" tab;
  • 6. Choose new default path for your storage pool.

Table of Contents



Windows Server

Q. Windows Server doesn`t see my HA target as one disk. Why?

A. You need to install MPIO (MultiPath I/O) Feature to make Windows recognize the HA devices properly.
You can find how to do it in the following manual
http://www.starwindsoftware.com/configuring-ha-storage-for-win-server-2003-and-2008 for Windows 2003(R2), Windows Server 2008 (R2).

Table of Contents



Q. Does StarWind supports Cluster Shared Volumes (CSV) in Hyper-V clusters?

A. Yes, StarWind iSCSI target fully supports SCSI-3 required to build a Hyper-V cluster. You can find how to make CSV in the following manual
http://www.starwindsoftware.com/cluster-shared-disk-resources-for-hyper-v

Table of Contents



Citrix Xen Server

Q. Citrix Xen Server doesn`t see any StarWind target.
How can I enable Xen Server-compatible discovery?


A. Please, edit StarWind.cfg file as described in the following manual and restart the service -
http://www.starwindsoftware.com/providing-ha-shared-storage-for-xenserver.

Table of Contents


VMware vSphere

Q. Does StarWind supports both ESX and ESXi?
How can I enable Xen Server-compatible discovery?


A. Yes, StarWind fully supports both hypervizors.

Table of Contents