Home network SAN setup

kaelwhale said:

The ethernet switch will be some kind of Dell PowerConnect probably, 24 gigabit ethernet ports and 2 fibre 2 Gbps ports.

Four of the ethernet ports will connect to the G5. The WAN port will connect to my modem. Another ethernet port will connect to my wireless access point. The two fibre ports will connect to an XServe RAID.

My questions:

Will this kind of configuration work?

Can I boot my Power Mac G5 from the XServe RAID, and if so, would that be faster than booting from the internal hard drive (1.5 Gbps SATA)?

Will my other computers (connected via WiFi) be able to connect to and backup to the XServe RAID?

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Usually when you see fibre port (SFP) on an Ethernet Switch, they're for linking multiple switches over long distances, or to reduce noise (or both.) They're talking plain Ethernet protocol over Fibre. That is NOT the same thing as FCoE or plain Fibre Channel protocol.

I don't think your plan to create a sort of hybrid iSCSI to Fibre Channel SAN is going to work with this hardware.

You didn't say which model of Dell switch, but I don't see them as having anything on the Ethernet switch side that will suit this need. They partner with Brocade, as most vendors of their ilk do, and resell Brocade FC switches.

You don't need a SAN switch if you're looking to connect a single storage array to a single computer.

You will need an HBA for the Mac to do this. The Apple branded FC adapters came with the cables you'd need for a point to point connection. You can use a single dual port card and connect to an Xserve RAID with both ports, or split the ports up between two computers.

If you really want a "real SAN", i.e. a Storage Area Network whereby you can connect more than two computers to the storage, you will need a real FC switch. There's really no way around that.

Can a G5 Mac with an HBA boot from an Xserve? Sure. I think you'd be better served with an SSD for boot and use the Xserve RAID for data. Of course, the Xserve RAID could hold up to 14 SATA drives. Not exactly screaming fast, but more spindles is always good.

I am going from memory here, but pretty sure the RAID box can't serve anything over its LAN ports directly. You need to share the drive using the G5 as a server. Thats my guess anyhow.

dazey said:

I am going from memory here, but pretty sure the RAID box can't serve anything over its LAN ports directly. You need to share the drive using the G5 as a server. Thats my guess anyhow.

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You are correct: the ethernet ports are for remote management (one per RAID card/array as the 14 drive bays are split 7/7 into independent arrays). There is no direct serve capability. The XServe RAID is designed to be connected to an always-on server (like an XServe) that would serve the volumes to clients.

There are two ways to serve data with a SAN:

1. All machines must be connected to a Fibre Channel switch (using Fibre of course) and then the storage must also be connected to the switch. Something such as Xsan must be configured on all machines in the Fibre network and the G5 will configure and host the volume. (Xsan 2.1.1 can be run on 10.5 http://support.apple.com/kb/HT1862)

When using Xsan, all machines will be connected to each other via Fibre as well as Ethernet. Usually two Ethernet ports are used, one for the Xsan metadata network (to query files and data locations) and the other to access the internal LAN/internet. (Xsan 2 setup guide: http://manuals.info.apple.com/MANUALS/0/MA610/en_US/Xsan_2_Setup_Guide.pdf)


2. Connect the Xserve RAID to the G5 directly via Fibre and share the volume via AFP/SMB/NFS/whatever.

Hope this helps.

mire3212 said:

There are two ways to serve data with a SAN:

1. All machines must be connected to a Fibre Channel switch (using Fibre of course) and then the storage must also be connected to the switch. Something such as Xsan must be configured on all machines in the Fibre network and the G5 will configure and host the volume. (Xsan 2.1.1 can be run on 10.5 http://support.apple.com/kb/HT1862)

When using Xsan, all machines will be connected to each other via Fibre as well as Ethernet. Usually two Ethernet ports are used, one for the Xsan metadata network (to query files and data locations) and the other to access the internal LAN/internet. (Xsan 2 setup guide: http://manuals.info.apple.com/MANUALS/0/MA610/en_US/Xsan_2_Setup_Guide.pdf)

2. Connect the Xserve RAID to the G5 directly via Fibre and share the volume via AFP/SMB/NFS/whatever.

Hope this helps.

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I don't mean to nitpick, but option 2 isn't really a SAN. It's just shared storage. I know a lot of vendors even use "SAN" sometimes when they mean an array, but we know they're not the same thing.

Yes, sell all of that **** and get a NAS.

kaelwhale said:

Thanks for all the tips and explanations!

I was hoping to have all of my computers access the SAN so that they would see it as a local disk. This would eliminate all of the annoying things about having network shares (not automatically connecting correctly, giving me errors when they are not at home, etc.). Obviously though I can't connect all of my laptops to a fibre switch, so I guess network shares are the way to go - unless anyone has a more elegant solution?

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If you get the right NAS unit, then with iSCSI each computer will be able to do this. See : http://www.synology.com/support/tutorials_show.php?q_id=468

kaelwhale said:

Thanks for all the tips and explanations!

I was hoping to have all of my computers access the SAN so that they would see it as a local disk. This would eliminate all of the annoying things about having network shares (not automatically connecting correctly, giving me errors when they are not at home, etc.). Obviously though I can't connect all of my laptops to a fibre switch, so I guess network shares are the way to go - unless anyone has a more elegant solution?

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You could get a fiber channel switch and some fiber channel cards to pull that off. You will need to setup Xsan to handle proper lock management.

SAN for a home network? Come on...

A good NAS and Gb ethernet network will work just as well for all practical purposes, with little to no maintenance, much less hassle and way less money.

juanm said:

SAN for a home network? Come on...

A good NAS and Gb ethernet network will work just as well for all practical purposes, with little to no maintenance, much less hassle and way less money.

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Totally agree. I have a low-power server doing Networked Time Machine, file sharing, iTunes, EyeTV, home automation, and Minecraft. Multiple disk drives for Time Machine/iTunes/file sharing. It's GIG-E and I often hit close to spec. You're wasting time and money on this.

juanm said:

SAN for a home network? Come on...

A good NAS and Gb ethernet network will work just as well for all practical purposes, with little to no maintenance, much less hassle and way less money.

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It all comes down to user preference, but personally i would prefer SAN. You don't have to worry about network speed limitations, and possible slow downs if many users are using your network. You could have a second network dedicated for NAS, but considering he already has the XServe RAID it may be more cost effective to just buy a fiber channel switch and some fiber cards.

You could probably pick up an XServe RAID, FC cards, and a 4gbps switch for under $800. The only issue is the scarcity of PATA drives, but they can still be found if you look hard enough. You could also opt for PATA to SATA adapters, but you would have to run 2.5" non enterprise drives (or SSD without trim support)

I don't think he has a Xserve RAID already - he has a G5 he wants to use as a server.

How many computers do you want to connect? Are they all wired? You can get a good Gig-E switch for $100 or so. Most computers have Gig-E already built in. The key here is "home network".

kaelwhale said:

*she

Relax everyone, I haven't actually bought anything!

Obviously there aren't many practical reasons to have a SAN at home; it's more for me to mess around with. Who wouldn't want to have their own fibre network?

Thanks for all the suggestions

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Which is exactly why i have one

But in all seriousness it's much faster than NAS. If you raid 0 the two host controllers (which XSan does by default) you can get really close to 2Gbps read and write speeds. Near 4Gbps reads if the data is in cache.

The hard disk controllers in the XServe RAID have their own RAID setup (0,1,3,5) for you to choose from, so redundancy is not an issue if you raid 0 the controllers together.

We have two of them put together in our office, and can easily pull 3.5 - 3.9 Gbps constant reads and writes which is combined through about 30 clients requesting large files nearly all day.

You can split the raid into multiple LUNS and see them as separate drives on all of the clients to boot from, which is a nice feature.

kaelwhale said:

*she

Relax everyone, I haven't actually bought anything!

Obviously there aren't many practical reasons to have a SAN at home; it's more for me to mess around with. Who wouldn't want to have their own fibre network?

Thanks for all the suggestions

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Who wouldn't? But it becomes a cost benefit thing. You're basically starting for scratch, because the bottleneck is gonna be the G5 server. Seems unlikely it will be able to push the full drive speed of 3gbs. How many computers are you supporting? Most of the time, my home server is turning electricity into heat supporting two computers and a home theater setup. I get close to 1gbs on gig-E. You can do that for next to nothing. Or you can spend thousands for some speed increase that you will probably seldom see. There's a reason even most professional work environments step their fiber down to gig-E when it hits the desktop - cost-benefit.

kaelwhale said:

I've been researching SAN networks over the last few days, and I have a general idea of what I'd like my home network to look like when it's complete. I'd love some feedback on my plan, and I also want to make sure that the hardware I buy will work together.

For my server, I have a Power Mac G5 with 10.5 Server. I plan to install three PCI-X gigabit ethernet cards and use link aggregation to achieve a 4 Gbps connection to my ethernet switch.

The ethernet switch will be some kind of Dell PowerConnect probably, 24 gigabit ethernet ports and 2 fibre 2 Gbps ports.

Four of the ethernet ports will connect to the G5. The WAN port will connect to my modem. Another ethernet port will connect to my wireless access point. The two fibre ports will connect to an XServe RAID.

My questions:

Will this kind of configuration work?

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There are two types of Link Aggregation, Fault Tolerance and 802.3ad. Fault tolerance configures one or more NIC's to respond to the same address and simply hands off network traffic to another NIC in the event of failure of the primary NIC. 802.3ad Combines NIC's for aggregate speed. I believe you are asking about 802.3ad, which in this case would not be effective. Fault Tolerance would be effective for your environment.

Why? The PowerConnect switches will support 802.3ad Link Aggregation but: The 4 Gbps will only take place between the server and switch. All other devices will bottleneck at their respective ethernet speed. Meaning, all your clients will also need to be using Link Aggregation in order for them to take advantage of the increase in speed. If all your clients are Gigabit ethernet, that's all you're going to get. Basically, 802.3ad Link Aggregation only works at the configured speed between two or more devices using the same configured speed.

Can I boot my Power Mac G5 from the XServe RAID, and if so, would that be faster than booting from the internal hard drive (1.5 Gbps SATA)?

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Yes, you can boot from an XRAID. You will see a slight performance increase and you also have the protection of redundancy in a RAID setup. But, this solution is very power hungry, and you may see your power bill spike. Also, PATA drives are getting expensive and large size PATA drives are getting expensive. The XRAID's only support up to 750 GB drives which are more or less extinct or cost prohibitive. If it's just a "play with it to see how it works" project, good for you. But if it's intended as a permanent solution, I would advise against it. It's too costly.

You could accomplish the same thing by RAID'ing the three internal drives during setup, and using the XRAID as storage. (I actually can't remember if 10.5 allows booting from Apple RAID. My Intel XServe's on 10.6.x can).

For an Apple SAN setup, all devices are connected to the SAN via fiber through a Fiber switch. The ethernet ports on the XRAID are used for remote management only, using Apple's RAID Admin. The only work around for fiber that I'm aware of is iSCSI. If you want a SAN, Storage Network Solutions has some interesting products in addition to an iSCSI initiator for Mac, and might be a more cost effective SAN if you really want a SAN. Their products also provide the file locking functionality for shared resources.

Will my other computers (connected via WiFi) be able to connect to and backup to the XServe RAID?

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Yes. But this will be accomplished by simple file sharing, not SAN.

I know this was a confusing post, and maybe I have no idea what I'm doing, but if anyone could advise me that would be much appreciated!

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If you're looking for functionality, a NAS is the way to go these days. I prefer Synology. I have two of them and they work great. I toyed with XSAN a couple years ago and found that it wasn't what I needed. I have all the equipment and decided it was overkill for what I needed. Based on your description, I suspect you are trying to accomplish the same. I've been in the same boat where I wanted to try something out and got reluctant feedback when asking questions. I hesitate to do the same, but I think a NAS will serve you better.

rlk

P.S. I would direct your attention to iSCSI though. Most, if not all NAS's support iSCSI targets and the SNS initiator mentioned above seems to work well, so far, (for me).