There is no 2TB limit to volumes. The SAN has a 15TB volume limit, and since Windows 2003 SP1, Windows supports GPT disks, which can go into the millions of TBs for size. NTFS can do up to 256TB with a 64KB cluster size.
Are you initializing the volumes as MBR? This would limit you to being able to use only the first 2 TB.
Using multiple volumes does have the potential to yield better overall performance, but giving each VM its own volume may cause more management overhead and if you end up with a very large number of volumes, you could run into the maximum iSCSI connection limit (1024 per pool for a PS6100).
A few notes:
- do not team NICs for iSCSI
- there is no current HITKIT for 2012 R2. The HITKIT allows using smartcopies and smartcopy replicas, which offer quick recovery options
- don't go with cheap switches for iSCSI
- just because a switch is sold as "iSCSI optimized" doesn't mean it's properly configured out of the box
- try to dedicate the switches to iSCSI traffic only
- link the 2 switches together with at least 2 cables via stacking or a LAG
- enable flowcontrol on all ports to the SAN and server (iSCSI) NICs
- set spanning-tree to portfast/rstp edge-port on all ports to the SAN and server (iSCSI) NICs
- set the mtu size to the highest that the switch supports (e.g. 9216 on Dell PowerConnect) on all ports to the SAN and server (iSCSI) NICs
- do not use the default vlan for iSCSI traffic, but untag the iSCSI ports
- If you bought your Equallogic system in the US, it should have at least a remote implementation service. If you installed it yourself, you can ask that remote team to check out your system and validate that it was set up correctly (this is a scheduled service).
Everything you have mentioned above is setup that way. Thank you for confirming.
We will be setting up GPT, so thanks for clarifying on the size limit.
We will be running about 15-20 VM's on this setup. SQL, File server and application servers.
I plan on giving SQL its own volume. If I give SQL its own volume (say 1TB, as we will be putting a data warehouse on here), should I just perform a default install or should a do a smaller volume (80gb) for the O/S for SQL and attach a D: (another volume, say 900GB) for SQL ?
One thing I would suggest in regards to having guests use iSCSI to connect to 1 or more volumes, use separate NICs (NICports) for guest iSCSI from host iSCSI (as you are using 1Gbit network cards (guess based on the PS6100 being 1Gbit)).
So you'd have 2 network ports (non-teamed) for the host's iSCSI; each has it's own IP.
Then you create 2 virtual switches in hyper-v and call them something like "Guest iSCSI Network 1" and "Guest iSCSI Network 2". Each virtual switch attaches to a single network port, but you uncheck the checkbox that says to allow management via that connection (this will remove any IP assigned to that NIC).
Now you give your VM 2 extra NICs (besides the one it uses to connect to your LAN) and each of those goes to one of the Guest iSCSI networks. You give each of the virtual NICs an iSCSI IP, enable jumbo frames (if the NIC driver permits), and install the HITKIT like Donald recommended (though the current HITKIT 4.6.0 only supports 2008, 2008 R2 and 2012, but not 2012 R2). Configure the iSCSI connections via the Auto Snapshot Manager (settings in the bottom right) and set up your volume(s) to allow just this VM access to them.
The HITKIT will let you schedule snapshots of the SQL Databases and allow rollbacks if/when needed.
Are you using ASM/ME to protect / recover SQL Server data? If so, please keep in mind that Smart Copies of the VM taken from the ASM/ME instance on the Hyper-V host - will, indeed, be application-consistent when using VHDx for SQL data. However, you will not get much granularity in your Smart Copy restores. You will be only be able to restore the VM and entire application-state from a point-in-time.
In contrast, using the Guest's iSCSI initiator to connect to it's volumes -- Smart Copies taken from the ASM/ME instance running on the Guest will be both application-consistent and allow for more granular restores of the database objects.
Just some considerations to ponder. Kindly advise if I can provide further information.
Dev Mgr
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9.3K Posts
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January 30th, 2014 10:00
You are selecting the host NIC that the guests can use for iSCSI yes. This should be a different NIC from what the host uses for iSCSI.
So you need at least 4 NICs (NIC ports) for iSCSI; 2 for the host and 2 for the guest(s).
Dev Mgr
4 Operator
•
9.3K Posts
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January 29th, 2014 06:00
There is no 2TB limit to volumes. The SAN has a 15TB volume limit, and since Windows 2003 SP1, Windows supports GPT disks, which can go into the millions of TBs for size. NTFS can do up to 256TB with a 64KB cluster size.
Are you initializing the volumes as MBR? This would limit you to being able to use only the first 2 TB.
Using multiple volumes does have the potential to yield better overall performance, but giving each VM its own volume may cause more management overhead and if you end up with a very large number of volumes, you could run into the maximum iSCSI connection limit (1024 per pool for a PS6100).
A few notes:
- do not team NICs for iSCSI
- there is no current HITKIT for 2012 R2. The HITKIT allows using smartcopies and smartcopy replicas, which offer quick recovery options
- don't go with cheap switches for iSCSI
- just because a switch is sold as "iSCSI optimized" doesn't mean it's properly configured out of the box
- try to dedicate the switches to iSCSI traffic only
- link the 2 switches together with at least 2 cables via stacking or a LAG
- enable flowcontrol on all ports to the SAN and server (iSCSI) NICs
- set spanning-tree to portfast/rstp edge-port on all ports to the SAN and server (iSCSI) NICs
- set the mtu size to the highest that the switch supports (e.g. 9216 on Dell PowerConnect) on all ports to the SAN and server (iSCSI) NICs
- do not use the default vlan for iSCSI traffic, but untag the iSCSI ports
- If you bought your Equallogic system in the US, it should have at least a remote implementation service. If you installed it yourself, you can ask that remote team to check out your system and validate that it was set up correctly (this is a scheduled service).
cpottsIT
9 Posts
0
January 29th, 2014 06:00
Thanks for the response.
Everything you have mentioned above is setup that way. Thank you for confirming.
We will be setting up GPT, so thanks for clarifying on the size limit.
We will be running about 15-20 VM's on this setup. SQL, File server and application servers.
I plan on giving SQL its own volume. If I give SQL its own volume (say 1TB, as we will be putting a data warehouse on here), should I just perform a default install or should a do a smaller volume (80gb) for the O/S for SQL and attach a D: (another volume, say 900GB) for SQL ?
cpottsIT
9 Posts
0
January 29th, 2014 09:00
Thanks Don. Does Dell have any whitepapers on this I can look at?
cpottsIT
9 Posts
0
January 30th, 2014 09:00
Thanks Dev.
When I create the virtual switch for the Guest iSCSI, am I selecting the iSCSI host pNIC?
Dev Mgr
4 Operator
•
9.3K Posts
0
January 30th, 2014 09:00
One thing I would suggest in regards to having guests use iSCSI to connect to 1 or more volumes, use separate NICs (NICports) for guest iSCSI from host iSCSI (as you are using 1Gbit network cards (guess based on the PS6100 being 1Gbit)).
So you'd have 2 network ports (non-teamed) for the host's iSCSI; each has it's own IP.
Then you create 2 virtual switches in hyper-v and call them something like "Guest iSCSI Network 1" and "Guest iSCSI Network 2". Each virtual switch attaches to a single network port, but you uncheck the checkbox that says to allow management via that connection (this will remove any IP assigned to that NIC).
Now you give your VM 2 extra NICs (besides the one it uses to connect to your LAN) and each of those goes to one of the Guest iSCSI networks. You give each of the virtual NICs an iSCSI IP, enable jumbo frames (if the NIC driver permits), and install the HITKIT like Donald recommended (though the current HITKIT 4.6.0 only supports 2008, 2008 R2 and 2012, but not 2012 R2). Configure the iSCSI connections via the Auto Snapshot Manager (settings in the bottom right) and set up your volume(s) to allow just this VM access to them.
The HITKIT will let you schedule snapshots of the SQL Databases and allow rollbacks if/when needed.
cpottsIT
9 Posts
0
January 30th, 2014 11:00
We do not have any additional pNICs to use. I tried using the host iSCSI, but performance was horrible.
michaelpacheco
66 Posts
0
January 31st, 2014 10:00
Are you using ASM/ME to protect / recover SQL Server data? If so, please keep in mind that Smart Copies of the VM taken from the ASM/ME instance on the Hyper-V host - will, indeed, be application-consistent when using VHDx for SQL data. However, you will not get much granularity in your Smart Copy restores. You will be only be able to restore the VM and entire application-state from a point-in-time.
In contrast, using the Guest's iSCSI initiator to connect to it's volumes -- Smart Copies taken from the ASM/ME instance running on the Guest will be both application-consistent and allow for more granular restores of the database objects.
Just some considerations to ponder. Kindly advise if I can provide further information.