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Adding a new thin provisioned storage to Xen Server 6.5

Started by Vedran Bojcic , 24 March 2015 - 09:01 AM
9 replies to this topic

Vedran Bojcic Members

Vedran Bojcic
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Posted 24 March 2015 - 09:01 AM

Hello everyone,

 

I`m a new user of a Citrix virtualisation platform. I`ve been using it since 6.2 SP1.

 

I have setup a new test enviroment. We have hard core GPU users so we have a server with GRID K2 card, HP 3Par storage with SSD disks.

 

I have created a new lun 2TB in size. Since yesterday it has been filed with machines up to 95% (This is the info from Xen Center) but at 3par management console i can see it is 300GB full.

 

Is there any way to turn on thin provisioning from the Xen Desktop or Xen server because i can`t make any new mashines?

 

P.S. I have turned on Xen Desktop thin provisioning or something when instaling Xen Server.

 

 

Thanks in advance.



Tobias Kreidl CTP Member

Tobias Kreidl
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Posted 24 March 2015 - 01:35 PM

For thin provisioning, your SR must be either a local one using  ext3 (not LVM) or using NFS.

-=Tobias



Vedran Bojcic Members

Vedran Bojcic
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Posted 24 March 2015 - 03:25 PM

Can HBA attached storage be formated using ext3? The 3Par doesn`t support NFS native. Ww would have to use a another physical server to be an NFS server.



Tobias Kreidl CTP Member

Tobias Kreidl
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Posted 24 March 2015 - 03:34 PM

No, only NFS as far as external storage goes, is currently supported for thin provisioning.  HBA devices are block-based and not file based, like NFS.  And, yes, you would have to either have another physical server or a storage device that natively supports NFS.

-=Tobias



konvikkt1 Members

kon vikkt
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Posted 25 March 2015 - 03:52 AM

shooting in the dark.. how about creating a partition in the raw lun using fdsik -l and then using it as ext using xe sr-create.. not sure if this is any sort of relevance. Need to test .



Tobias Kreidl CTP Member

Tobias Kreidl
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Posted 25 March 2015 - 03:59 AM

@Vedran: If it is a local SR, the default is to create it an an LVM. So, you'd need to destroy it and re-create it via the CLI. There are a number of blog articles you can easily find that give the exact syntax or I think it's also given in the XenServer in the administrator's guide.

-=Tobias

 

Syntax is like this:

xe sr-create host-uuid=<valid_uuid> content-type=user \
name-label=<"Example Local LVM SR"> shared=false \
device-config:device=/dev/sdb type=ext



Vedran Bojcic Members

Vedran Bojcic
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Posted 25 March 2015 - 08:06 AM

@Tobias: Thanks for that, but our servers don`t have local storage at all. Xen server is booted from small SAN storage (30gb). And all the storage for the VM is on HP 3Par 7200.



Vedran Bojcic Members

Vedran Bojcic
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Posted 25 March 2015 - 08:20 AM

It is interesing that one storage of 2TB is seen by fdisk as 4 disks 2TB large because of multipathing.

 

So i basically colud`t format on of them (nevermind that it cooul be only formated using parted wich insn`t installed on Xen Server by the default).

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Michael Wachtmann Members

Michael Wachtmann
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Posted 02 December 2015 - 06:33 PM

IF I'm understanding this, if you want the local storage to be thin provisioned, you have to choose EXT, because LVM is thick provisioned only? any other caveats?

 

I followed http://support.citrix.com/article/CTX121313 and http://support.citrix.com/article/CTX130897 and a number of third party blogs which incorrectly it seems were labeled as directions to create a "Thin Provisioned Local Storage" but used the command set for LVM.

 

Obviously you cannot correct 3rd-party blogs, but the CTX articles make no clear mention of provisioning. If those could be edited that might help other people.

 

As it stands now, I guess I need to create another SR, I guess NFS to another storage server temporarily, Move all of my disks over, obliterate my 12T local storage, recreate it, and then move them all back. For some unrelated reason, I can only get move operations over any type of network share to travel at about 100BaseTX Speed so this will be fun.

 

Another thing I might as well ask, some tutorials mention the command with "device-config:device=<Device Path>" while others have an additional step to find out the disk ID and use "device-config:device=/dev/disk/by-id/<scsi-xxxxxxxxx>" ....Is there any rhyme or reason to which one you choose?



Boby John Members
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Boby John
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Posted 02 December 2015 - 08:07 PM

 

Another thing I might as well ask, some tutorials mention the command with "device-config:device=<Device Path>" while others have an additional step to find out the disk ID and use "device-config:device=/dev/disk/by-id/<scsi-xxxxxxxxx>" ....Is there any rhyme or reason to which one you choose?

 

 

 

Both are the same

 

"device-config:device=<Device Path>"

 

The above device path is what you find from fdisk -l and this would be usually listed like /dev/sda or /dev/sdb.

 

The other one is "device-config:device=/dev/disk/by-id/<scsi-xxxxxxxxx>" 

 

This is the path that you get from /dev/disk/by-id.-------------------- this is the path directly to the device and it includes SCSI id.

 

You can use either one of them - it wont matter!