Best Practices for Large Shared Folder on VNXe

Question

Hi, I'm in the process of setting up an EMC VNXe 3100 with 12x 2TB NLSAS drives, with the intention of using as much of the available capacity for a CIFS share.  I've hit a couple of limitations and I'm hoping that people might be able to point me in the right direction to set this up in the most appropriate way. Issue number one is that the VNXe doesn't allow me to setup a 12-disk RAID-6 array, so I've had to set this up as 2x 6-disk RAID-6 arrays, which means that I've lost 4TB of usable storage.  From what I read on these forums, this is to be expected, but I find it a little ridiculous as so most other SANs on the market don't suffer from this limitation.  Is there a good reason for this?  Does EMC have any plans to support a 12-disk RAID-6 array on NLSAS media in the future?  If so, I might be prepared to wait!  Perhaps I can put this on my Christmas wish list? The second issue relates to configuring a large shared CIFS volume on the VNXe.  As I see it, I have two options: 1) Create a large shared CIFS volume on the VNXe. (I believe I can create a 16TB volume).  I'm hesitant to do this, as I presume I'll be missing out on some nice Windows features such as Volume Shadow Copy snapshots (where users can restore previous versions of their files via 'self-service' in Windows Explorer), and I presume that the VNXe permissions model will be somewhat different to Windows' built-in offering.  Please correct me if I'm wrong. 2) Setup a Windows file server (physical or virtual) and allocate a number of 2TB iSCSI volumes on the VNXe, then use Windows spanning feature to create a large volume.  This way, I can keep the nice Windows features such as Volume Shadow Copy snapshots, and the Windows permissions model.  I'm concerned that creating a 16TB volume spanned across 8x 2TB iSCSI volumes is going to be a performance nightmare.  Has anyone tried this, and if so can you please comment on the performance? I'd really appreciate it if someone could point me in the right direction to get this resolved without too many nasty hacks.  Perhaps there's something I've forgotten? In case anyone is curious, the file share is intended to contain raw data samples for an engineering firm.  These files can be several hundred gigabytes each, so the users would prefer one large space to dump these files, rather than lots of 2TB shares. Thanks in advance for any advice!

devijb · Answer

Hello Trevor,

VNXe can take checkpoints of your CIFS shared folders; and expose them to your users, through the Microsoft API;

Your end-users will see checkpoints exactly the same way as if you are using a Windows File Server...

(You need the local protection pack for this, the good news is: this local protection pack is shipped for 0$ with every VNXe3100; Christmas is not so far !)

Regards, Benoît

trevor_p1 · Answer

Hi Benoit,

Thanks for the information - the Local Protection Pack is a very pleasant surprise and I'll consider it my Christmas present from EMC!

My other concern was regarding configuring permissions on the filesystem - can I assign permissions to files and folders on the share by using Windows Explorer, just like a regular Windows server? Does the VNXe support assigning permissions according to Active Directory group membership?

I guess what I'm trying to work out is which features I will miss out on by retiring the old Windows file server and doing everything on the VNXe.

When I'm migrating the data across, will I need to do anything special to retain the existing permissions, or will I need to reassign them once everything has been copied?

Sorry for all the simple questions - this is my first experience with using a SAN for file-level storage (rather than block-level) and I just want to make sure I get things right the first time!

Thanks,

Trevor..

devijb · Answer

Hello Trevor,

VNXe can do all of this for your (AD groups, you also have access to the security tab + advanced security tab etc…); you can also use the Microsoft MMC to manage the VNXe Share permissions;

For the datamigration, you can use robocopy for example, and keep the permissions on the migrated files/directory;

Regards, Benoît

VNX

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