SANs - Where to start?

NightShadow · 24 Mar 2010 at 15:28

I am looking into SANs and really am not sure where to start. We are looking to implement a SAN which will cover 2 geographic locations for redundancy/DR and I have been looking at the HP LeftHand networks P4300 16TB kit which seems OK but there isn't much info about how it all works. It will be used to host initially 250 Exchange 2010 users (roughly 200GB) but will probably eventually host our file servers etc. Where can I really learn about SAN technologies?

Do SANs have much disk redundancy?
Do all SANs incorporate de-duplication?
Can the P4300 16TB kit be split as 1 unit at each site? What would the total available storagebe?

As you can see I have lots of questions and havn't really found anything useful on the web so am after any pointers on where to start and what's good etc.

TIA

m4cc45 · 24 Mar 2010 at 15:48

1. Yes - you can use Virtual RAID which basically means you can use RAID 0 / 1 / 5 etc.
2. Assuming you mean if two exact files exist then it automatically 'removes' one. The short answer is no.
3. Depends on the SAN if you're using Fibre Channel then the SAN needs a physical connection to the kit. If you are using iSCSI then you need LAN connectivity. You can split the disks however you like really. There will be an upper file size limit dependant upon guest Operating System, etc.

M.

DustyMiller · 24 Mar 2010 at 17:55

First things first, what kit do you currently have ??, what budget do you have for the new "Storage Environment" Then you go to look at options.

Ringiho · 24 Mar 2010 at 19:13

NightShadow said:
Do SANs have much disk redundancy?
Do all SANs incorporate de-duplication?
Can the P4300 16TB kit be split as 1 unit at each site? What would the total available storagebe?

TIA

The redundancy is obviously entirely dependant on the RAID array used, something like RAID50 can be pretty good.
The LeftHands (can be) setup to duplicate across sites and have a 'RAID' across the two (or more). So a RAID5 on each with a stripe across to give a RAID50 in theory.
Again total storage is dependant on the RAID setup

Deathwish · 24 Mar 2010 at 20:04

Have a look at Hitachi AMS series, very competative pricing and good solid kit. (We have one)

kippermitten · 25 Mar 2010 at 16:09

Do SANs have much disk redundancy?
- yes. personally id say avoid the Hitachi SANS - they are not automagic LUN provisioning and be aware that if you loose a shelf on the AMS series the SAN locks itself to prevent data loss, no storage on the SAN is accesable in that scenario.

HP EVA SANs auto provision RAID groups and LUNS over all available shelves and you can loose a shelf or two upto a point and carry on working.

Do all SANs incorporate de-duplication?
- No they dont. Dedupe is normally an available option for certain SANs.

Can the P4300 16TB kit be split as 1 unit at each site? What would the total available storagebe?
- I think they can but its a license option. Also its not a "true" SAN, its a storage server made into an Appliance running the left hand software.

I dont think you will get the IOPs from a LeftHand solution given the number of users your looking at.

Depending how much $$$ you have at your disposal look at the EVA4400 starter SAN kits, get two SANs and the replication HP software for repl between sites.
One thing to remember is that if you go for an iSCSI SAN you really need seperate network switches to push the packets for storage around.
The EVA4400 can do Fiber Channel or ISCSI, personally Id go FC...if you do though, youl need FC HBAs(Host Bus Adaptors for the servers/hosts to connect to the storage.

FYI - We use two HDS AMS1000's , one in Primary one in DR, we use Falconstor IP stor to provision the storage to the VSphere hosts and do replication from primary to the DR site. We also have just bought a 2nd hand EVA4000 to use as our test and Dev SAN, much prefer the HP after working with them for years.

Nikumba · 26 Mar 2010 at 09:02

SANs have raid so they have redundancy in that, but the Lefthand software also has what is called Network RAID, which means you can use several SANs in a RAID array, I am not sure how it fully works, I just know it does.

We have two Lefthands now, and they are brilliant. All the configuration is done through a nice GUI, allows you to set-up volumes, snapshots, remote snapshots etc. One of the nice things about Lefthand is you get all the options in the price, unlike with other SAN vendors you get a base and you have to add on top of that.

I agree with kippermitten in that the 16Tb may not be adequate for you, but do you need all that space? Of course it depends on how big your file server will be but the model you are looking at is the starter SAN if you like so has fairly low IOPS, which may or may not be an issue, as compared to EX2003, EX2010 has 85% less IOPS.

Depending on your budget I would be looking at two P4500 G2 3.6TB SAS or
P4500 G2 5.4TB SAS, and putting one on a remote site and using remote snapshot that is free with Lefthand.

Are you using virtulisation with your Exchange server or is this just for storage?

Below are the performance of the Lefthands, sorry its a bit misaligned, but dont know where the VB table option is

Code:

HP P4000 G2 Products	                        RAID 0	RAID 5	RAID 6	RAID 10
P4500 G2 21.6TB Multi-Site HA SAN	                   x	6,800	5,000	9,600
P4500 G2 10.8TB Virtualization SAN   	           x	3,400	2,500	4,800
P4500 G2 60TB Scalable Cap. SAN	                   x	3,375	2,400	4,000
P4300 G2 7.2TB SAS Starter SAN	                   x	2,200	1,700	2,500
P4300 G2 16TB MDL SAS Starter SAN	           x	900	700	1,200
P4500 G2 3.6TB SAS	                                   x	1,700	1,250	2,400
P4500 G2 5.4TB SAS	                                   x	1,700	1,250	2,400
P4500 G2 9.0TB MDL SAS	                           x	675	480	800
P4500 G2 12.0 TB MDL SAS	                           x	675	480	800
P4300 G2 2.4TB SAS	                                   x	1100	850	1250
P4300 G2 3.6TB SAS	                                   x	1100	850	1250
P4300 G2 6.0TB MDL SAS	                           x	450	350	600

Kimbie

brainchylde · 26 Mar 2010 at 13:40

What are you looking to achieve with the SAN?

egraphixstudios · 26 Mar 2010 at 22:06

Hitachi AMS series.. good pricing, solid kit. I use it for our exchange store and backup.

Shaz]sigh[ · 27 Mar 2010 at 16:36

NightShadow said:
Do SANs have much disk redundancy?

Disk redundancy is dependant on your configuration, what you want is redundancy throughout the array.

NightShadow said:
Do all SANs incorporate de-duplication?

No SANs incorporate primary tier dedupe, you'd need to look at something like an Ocarina box in front of it. For file based stuff (NFS/CIFS), NetApp, EMC, etc do 'free' dedupe (free once you've bought the cifs/nfs license and it's scheduled).

NightShadow said:
Can the P4300 16TB kit be split as 1 unit at each site? What would the total available storagebe?

Don't know about the Lefthand stuff. First thing's first, what do you want to achieve by moving to shared storage? What's the driver? Reduction of storage silos? Simplified management? Virtualisation?

If I wanted to do Exchange for 250 users in 2010 I'd use the application's own replication tech and use DAS.

Any questions - fire away.

kippermitten · 29 Mar 2010 at 16:12

egraphixstudios said:
Hitachi AMS series.. good pricing, solid kit. I use it for our exchange store and backup.

Id debate that now.

3 years in and HDS are EOL the AMS1000 - as a Law firm we are having to look at replacing it in May next year when it will be barely 2.5 years old as we wont risk parts being tough to get hold of.
HDS wont give up the life cycle of the AMS2500 etc series either.
Coupled with the non auto disk provisioning therefore having to manually design your whole storage layout on the shelves and disks and a terminally crappy GUI...id say stay clear.
Granted they do have good performance but only if you design the layout of your disks nigh on perfectly.
Having had to squeeze in all our systems initially into 9 shelves by doing a manual design spreadsheet was not the most fun Ive ever had - and then overlaying that design onto a DR SAN with same capacity but less shelves, even less so!

Deathwish · 29 Mar 2010 at 17:22

The AMS2000 series is a lot better in terms of functionality than the AMS1000 series. Since ours was installed I've only ever been into the GUI twice, when adding new shelves. Our HDS engineers are very proactive in arranging firmware upgrades etc FOC.

Skidilliplop · 2 Apr 2010 at 00:15

We have a similar requirement for DR. We don't use Deduplication but I think our units will probably do it with some additional software.

We're using Equallogic PS6000/4000 series in the SAS flavour. They have the option to replicate volumes to another SAN unit and do load balancing across trays based on the IOPs hitting a volume. So if you were so inclined you could have a tray full of SSDs and the hardest hit volumes would get shuffled onto that.
They're iSCSI so they're cheap and easy to set up and get going.
Do be aware the replication is based on a snapshot taken and replicated on a schedule, it's not byte level.

We also have a Hitachi SMS unit because one of our medical system vendors insisted on it to not invalidate support agreements. To say that it is the most apalling excuse for a product i've seen really is an understantement. If the bigger brothers have anything in common i'd stay well clear. The Modular storage manager software is horrendous and they haven't even bothered to translate half the menus properly. In 3.5 months we've had 2 replacement units in addition to the original. One of which managed to fail within the time it took to complain that auto-migration from the faulty unit to the new one wasnt working.
Enough to put me off for life.

HP Lefthand are also very good bits of kit and I did look into them as a solution but they are very expensive in comparison. For the size of application you've described I don't think you'd need them. I think the P4500 costs something like £25-30k per box as opposed to about £12k for a PS6000, 16k max.

DustyMiller · 3 Apr 2010 at 21:46

I have just put a pair of NetApp filers in, and have the license for De-Dupe, and Snapshots, (Vault & Mirror).

Netapp snapshots are byte level changes, i.e. they only transfer the actual data blocks that have changed since the last snapahot.

I looked at Equalogic, and they didnt do a box, that was capable of De-Dupe, or if they do, they didnt try to sell me one, knowing that it was one of my primary requirements.

Netapp also do iSCSI, FC, and CIFS / NFS aout of the box, and also have NDMP as standard. I love em, they are great, the only down side is there are three different tools needed to manage then easily.

NetApp system manager is great for initial setup, and creating volumes & things.

NA Admin is then the best for CIFS / Share management

And then the good old CLI for everything else.

Sorry a bit off topic, but NetApp is very very good gear.

zetec452 · 4 Apr 2010 at 18:33

I recently looked for a new san (single site) and chose the Dell Equallogic PS4000x. My heart was with HP LHN as I had used them before. The Equallogic is a very polished unit, very easy to manage and has full redundancy from a single unit.

My main criteria was unfortunately price and Equallogic met my budget and needs nicely. Not sure if that helps.

.

Dell did come to site and demo the unit which was nice.

brainchylde · 4 Apr 2010 at 20:10

JonRohan said:
I recently looked for a new san (single site) and chose the Dell Equallogic PS4000x. My heart was with HP LHN as I had used them before. The Equallogic is a very polished unit, very easy to manage and has full redundancy from a single unit.

My main criteria was unfortunately price and Equallogic met my budget and needs nicely. Not sure if that helps. .

Dell did come to site and demo the unit which was nice.

+1 for this. Management, cost... unbeatable.

NightShadow · 7 Apr 2010 at 16:18

Wow, a lot of replies to this, havn't managed to fully read through yet but thought I should at least reply and update with requirements.

Were looking at implementing several virtual servers, mainly mail and B2D based with a view to move file server storage onto them in the long term. The main requirement is to have the data replicated to a separate site so that if one site should go offline for whatever reason the other site can continue to access emails, files etc.

I'm not sure we actually need De-duplication now that I have looked at it further. Will check out some of the suggested kit in the meantime to see what else is out there.

Thanks again

JBod · 7 Apr 2010 at 22:05

Depending on your budget 3Par are about the best at SANs. Awesome management interfaces.

No one has asked a very important question though, are you sure its a SAN you need and not a NAS? They are two distinctly different things targeted for different storage needs.

Are you able to share your budget? As it will quickly determine what level you are aiming at - Shoestring (Supermicro+Opensolaris with ZFS) - Entry level (Dell/HP) - enterprise (Netapp/BlueArc/3Par) - bullet proof bank storage (EMC). What kind of disks? SATA? SAS? FCAL?

Its not worth touching a EMC unless you have about £1mil to spend as their lower tier products are utter utter rubbish.

NightShadow · 8 Apr 2010 at 15:00

JBod said:
Depending on your budget 3Par are about the best at SANs. Awesome management interfaces.

No one has asked a very important question though, are you sure its a SAN you need and not a NAS? They are two distinctly different things targeted for different storage needs.

Are you able to share your budget? As it will quickly determine what level you are aiming at - Shoestring (Supermicro+Opensolaris with ZFS) - Entry level (Dell/HP) - enterprise (Netapp/BlueArc/3Par) - bullet proof bank storage (EMC). What kind of disks? SATA? SAS? FCAL?

Its not worth touching a EMC unless you have about £1mil to spend as their lower tier products are utter utter rubbish.

Pretty sure it's a SAN we are after, B2D in Backup Exec requires "direct attached" storage IIRC which we can't do with a NAS, also from looking around a SAN has a lot more built in redundancy which is essential due to the data being held on there. The budget will probably only allow for "entry level" solutions such as the HP LeftHand and Dell offerings. As for disks, whatever seems to offer the best bang for buck, SATA would probably be fine.

JBod · 8 Apr 2010 at 20:21

NightShadow said:
Pretty sure it's a SAN we are after, B2D in Backup Exec requires "direct attached" storage IIRC which we can't do with a NAS, also from looking around a SAN has a lot more built in redundancy which is essential due to the data being held on there. The budget will probably only allow for "entry level" solutions such as the HP LeftHand and Dell offerings. As for disks, whatever seems to offer the best bang for buck, SATA would probably be fine.

Seems fair enough, the redundancy is identical for both SAN and NAS as that is controlled by the various RAID offerings available.

If you can make sure you get the enterprise ready SATA drives, they are designed for 24/7 operation in a high vibration environment where there are plenty of other spinning platters.