Server+NAS+SAN = Confusion

[mcloum]

Hi folks,

 

A few weeks back i posted about connecting up a NAS and SAN to my new servers...I since figured out how to connect the NAS up but since found out imay have done it arse about face. Im told the SAN server (12tb) should be the main storage area and the NAS (4TB) used for backing up too? to me that seems backwards....if i ever filled the 12tb SAN it would never fit on the NAS unless i stuck more drives in which the academy hasnt budgeted for, at least not until we move to a new building which is about 3 years away.

 

Can anyone point me in the right direction?

[Chillibear]

Not that it's much help (probably sucking eggs time), but normally SAN solutions tend to be faster and so will be used as the primary storage system, then a cheaper NAS solution is used to backup the SAN. That said if your storage is being shared out to lots of clients a SAN solution is unlikely to be suitable. SAN solutions tend to be deployed in a server environment where each server requires fast block level access to the disks or in video post production where each client needs fast access. NAS systems essentially do the same, but over standard network protocols, CIFS/SMB, NFS, AFP, etc.

 

You'll often find the situation where a pool of servers share storage via a SAN and one or more of those servers then share the storage out to the client workstations (ie one of those servers becomes a NAS head) then a dedicated NAS is added for backups - ideally remotely located. NAS generally being used since it's often faster to backup to than tape.

 

So as ever there is never a totally right or wrong way of doing things. Totally depends on what you want to achieve. Perhaps if you describe the environment and objective we can give you some suggestions.

Edited August 18, 2009 by Chillibear
typo

[mcloum]

to be honest the way i have it in my head would be ok, at the moment the NAS is connected to one of the server and setup in a RAID 5 (8 disks with a spare) and it is shown in the servers My Computer formatted as GTP with space of about 4tb

 

I assumed i would just share folders off this NAS box and connect clients accordingly. My problem at the moment is im not sure what to connect the SAN too. Is the second port on the RAID card in teh server or the NAS box? instructions are pretty rubbish to be fair.

[DMcCoy]

What servers do you have?

What storage boxes do you have?

What SAS/Network/Fibre (if any) cards do you have?

What Network/Fibre switches do you have?

 

The SAN will be for primary storage, NAS would be secondary/backup if you have both.

 

The SAN wil be iscsi or Fibre, unless it is a DAS (Direct attached storage, which could be SAS). It is most unusual to get something like a 12TB SAN box without professional services for the install (not that I ever used mine from Dell).

 

What exactly did the Academy buy the SAN for? Storage? Virtualisation? extravagance?

[mcloum]

ok tbh i didnt have a hand in the decision making for this so im not sure what the consultant had in mind as to what the system was going to be setup like! sales men!!!

 

Here is what i have at the moment:

 

http://img233.imageshack.us/img233/8415/sdc10404.jpg

 

Top unit is the 12TB SAN, Next is the NAS, next is the server is installed the RAID card into. The RAID card is a HP P411 Smart Array Contorller.

 

 

The kit is as follows:

 

3 x DL380G5

1 x MSA60 (4TB NAS)

1 x MSA2000 (12TB SAN)

 

The guy from the LEA who was helping us with this (I told them i needed help cause im not a hardware guy) has gone off on leave due to family matters.

 

Help!!

[Willott]

I am slightly bemused by what has been spec'd. The MSA60 is a DAS (direct attached storage) device (not NAS, as it's not really networked), so would only be connected to one server. It's also significantly smaller than data that may be backed up, and is attached to one server, so couldn't be stored elsewhere for DR backup type reasons, do you have a tape backup library? This would mean the MSA60 would be for D2D backups, and have tape for full weekly backups (using the MSA as incremental/differential backup storage). If not, something 'interesting' has been spec'd.

 

I've got one of the MSA2012FCs (the fibre channel version), with no DAS and backing up direct to tape. The only thing I'd consider adding to this is a NAS to do D2D backup, DAS would only really beat this in speed (but NAS is relatively quick access compared to tape, and can be placed remotely, so would be suitable for DR).

 

I'd suggest contacting the LEA and see if they can put you in contact with the suppliers, from my experience, the LEA guys don't work out the system, they get the supplier's hardware team to do that, so they may be able to help.

 

Cheers

 

Will

[Willott]

Oh, from the looks of it, your MSA2000 is the ISCSI variant with dual controllers, which is good for recundancy. I'd suggest using 2 switches, with 1 port from each controller connected to each switch to keep things fully redundant. How many NICs/ports have your DL380G5s got?

[mcloum]

The servers have 2 onboard and 1 card. Do i just whack in a normal Cat5 cable into the iSCSI port and then into the switch? Assuming i have to assign an IP to the iSCSI port then use the initiator on server 2008 to setup the target?

 

What will the performance be like with iSCSI? i've read its not that much slower than Fibre channel?