Mounting a LUN via SnapDrive (from a snapshot) just creates a pointer file and brings up the LUN. Again, the fractional reserve setting being set lower drives the space overhead (default is 100%, but can be set lower - however, you need to be VERY careful here as setting it too low could mean running out of space, which would mean corruption).
SnapMirror is straight forward - the only trickery is that volumes are _never_ guaranteed for the mirror until the snapmirror relationship is broken (snapmirror break) - at this point, you have to have enough aggr space to guarantee the vol size.
FWIW, we have about 10000 users across 3 major sites, and several smaller sites - all have home directories and group shares on FAS960 clusters (1 head for user data, 1 head for application support - for each of the three major sites). There is probably 13TB of home/shared data right now, and maybe 20 million files. We've had NO issues to speak of, and we rarely upgrade the filers. Over the last 2 years, we've upgraded from 7.0.0.1 to 7.0.3 to 7.2.3 - every time a seamless process with minimal downtime windows for the actual upgrade/reboot process (CIFS sucks for CFO - still creates an outage... thanks Microsoft!!!! By contrast, iSCSI FCP and NFS work great).
We heavily utilize DFS for ease of mapping with home directories, and ease of DR.
-----Original Message----- From: Milazzo Giacomo [mailto:G.Milazzo@sinergy.it] Sent: Sunday, February 24, 2008 7:02 AM To: Klise, Steve; Glenn Walker; toasters@mathworks.com Subject: R: Suggestions and opinion need: LUN for file server and Snapshot
Thank you very much for your answers, nevertheless it's Sunday :-) Waiting for some other 'business day' answers I have now some arguments collected to try to convince my customer to adopt a 'native CIFS server' strategy. And, as alternative, to link NetApp shares to a Windows DFS server! I agree with you about SnapDrive (already planned together with DSM) to manage the Snapmirror also but, in the worst case I will be forced to map some LUN to Windows what's about volume sizing? Do I have to size it twice as LUN size? (tremendous waste of space in this 'file server only' case!) Do I have to size it twice also for a Snapmirror only snapshotting? I mean, If I use the normal snapshot reservation on the volume containing the LUN, will Snapmirror have space for its snapshots?
Regards,
-----Messaggio originale----- Da: Klise, Steve [mailto:klises@caminomedical.org] Inviato: domenica 24 febbraio 2008 5.28 A: Glenn Walker; Milazzo Giacomo; toasters@mathworks.com Oggetto: RE: Suggestions and opinion need: LUN for file server and Snapshot
I have to say I am at an almost 100 percent Windows shop, and to be honest, its getting off the Microsoft teat is a challenge. We are finally moving most windows file servers to Netapp.
We have a 3020 that has over 2000 users on 1 shelf of SATA 500GB disks with roaming profiles, home folders, etc on it and I have had ZERO complaints about performance (most of the users come in from remote sites so the WAN is the bottleneck, but most site have 10-100MB connectivity back in).
One thing to sell is the Windows boxes will not have to be patched as much as a windows server, the extra U space, power etc, you have to built in snaphots for rapid recovery, and the windows guys can just MMC to the filer and manage it like the near and dear Windows GUI we hold so closely.
I would take the 20% off, and not take snapshots. Just give the LUN, and if you have the luxioury, snapmirror the data to another filer. When the windows box fails, you can mount the snap on the other filer and save the day.
If they already paid for the CIF license, I would ask why they paid for that if they didn't want that functionality.
just my thoughts, Im not a Netapp sales guy, but maybe starting to sound like one...
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From: owner-toasters@mathworks.com on behalf of Glenn Walker Sent: Sat 2/23/2008 5:41 PM To: Milazzo Giacomo; toasters@mathworks.com Subject: RE: Suggestions and opinion need: LUN for file server and Snapshot
So, first thought is if this is the plan then it is a bad one and maybe they shouldn't even bother with a filer. Kinda like using an F1 car to commute to work: it'll get the job done, but it doesn't really make much sense.
Second thought is that they can use fractional reserves, or completely disable snapshots and rely on VSS and hope for the best. Snapmirror wouldn't care - it would just follow these rules from the source.
Honestly, with the lack of common sense shown by his IT partners, maybe local storage is the way to go...
-----Original Message----- From: owner-toasters@mathworks.com [mailto:owner-toasters@mathworks.com] On Behalf Of Milazzo Giacomo Sent: Saturday, February 23, 2008 1:01 PM To: toasters@mathworks.com Subject: Suggestions and opinion need: LUN for file server and Snapshot
Hi toasters,
I've a customer who's planning to adopt a FAS2020 with a lot of SATA space to use it for Windows file servicing (user data, roaming profiles...) BUT, here's the "but" he has to map this space with a LUN to a new physical server running W2K3 because, the people who manage his infrastructure "want to see" a "real" Windows server...I've explained him that they can manage roughly all using the MMC but he said me that they want to "see" services, RDP and so on :-(
So the only way you know, is to create some LUN and assign as drive or mount point (anyway this could make easier data migration using maybe Windows DFS etc...)
But I would to focus your attention to the NetApp side of issue: snapshots... You know that a volume containing some LUN has to have at least a size double of the LUN, when you create it using Snapdrive the size is autocalculated answering "y" or "n" to that question "do you want to reserve..." I'm asking myself what sense could have to take snapshots of a LUN for a file server usage (not a db!) and after all, what's the sense to restore a volume, so that an entire LUN...so that an entire windows disk!!! Maybe with inconsistencies too...
Another question: I've never had the change to try it...can I use Microsoft VSS options to make a little bit of versioning on this disks coming from NetApp LUNs?
And now the big issue. This customer want to reply using Snapmirror on a remote 2020, so I need snapshots area, so do I have to create a volume DOUBLE of those LUNs size? Or in this case the default of 20% or less is enough?
As usual, many thanks!