HawaiiKai
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new to EqualLogic

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Can an EqualLogic volume be assigned to more than one Server?

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Dev Mgr
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RE: new to EqualLogic

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You can add the new server's IQN or iSCSI IP to the volume's Access Control List in advance. By default Equallogic will only allow 1 server at a time access to the volume (i.e. "Not Shared"). To change this, select the volume, go to the properties and on the advanced tab. The checkbox there is for allowing multiple servers with different IQN names (and each server should have a unique IQN name) to attach to that volume.

Once you shut down or disconnect the 'old' server (and maybe wait a few seconds for the array to register the disconnect) you can connect the new server.

If your servers are running VMware you can share disk access safely as the VMFS filesystem is safe to share disk access. However, do NOT allow Windows servers (NTFS) to share disk access unless those Windows servers are part of the same cluster. If you're using Linux, only certain filesystems are cluster aware (and therefor safe to share between multiple servers at the same time). If you're using XenServer, you'll want to check with Citrix what the requirements are to safely share disk access between multiple servers.

Member since 2003

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RE: new to EqualLogic

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Presuming that you have a cluster filesystem in place, then yes.   EQL provides no protection against filesystem corruption if you don't have such a filesystem in use.  EQL is a SAN, so block storage, not a NAS device.  Each server will believe they exclusively own the volume and can/will overwrite data w/o regard for the other server.  

What are you trying to accomplish?  I've seen customers try to do that for backup, besides corruption, the other drawback is updates to the volume from the primary server, aren't see by the backup server after the iSCSI connection is made by the backup server.   Again, that's something a cluster file system offers.

You can allows this at the CLI with:   GrpName>vol sel VOLUMENAME multihost enable

Or in the GUI under volume properites.

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HawaiiKai
1 Copper

RE: new to EqualLogic

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We are replacing servers and the new servers have new names and IP addresses.  So, my thought is to "re-assign" the storage from the old to the new server.   However, if I can assign to both (and, the new server will not be powered down after the storage is assigned) it will save me time as I also need to do upgrades and patching on each server now.   I am not a SAN admin but if the storage can be assigned to new server now then I won't need to interrupt our SAN administrator once the upgrades begin....and, that will occur "off hours".

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Dev Mgr
5 Rhenium

RE: new to EqualLogic

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You can add the new server's IQN or iSCSI IP to the volume's Access Control List in advance. By default Equallogic will only allow 1 server at a time access to the volume (i.e. "Not Shared"). To change this, select the volume, go to the properties and on the advanced tab. The checkbox there is for allowing multiple servers with different IQN names (and each server should have a unique IQN name) to attach to that volume.

Once you shut down or disconnect the 'old' server (and maybe wait a few seconds for the array to register the disconnect) you can connect the new server.

If your servers are running VMware you can share disk access safely as the VMFS filesystem is safe to share disk access. However, do NOT allow Windows servers (NTFS) to share disk access unless those Windows servers are part of the same cluster. If you're using Linux, only certain filesystems are cluster aware (and therefor safe to share between multiple servers at the same time). If you're using XenServer, you'll want to check with Citrix what the requirements are to safely share disk access between multiple servers.

Member since 2003

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HawaiiKai
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RE: new to EqualLogic

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many thanks.   sounds like a good plan

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