Has anyone ever actually used Xsan?

[Essence_of_War]

Just curious. I see it mentioned as a thing that OS X server supports, but I have never encountered anyone who actually uses it. In fact, even reviews of OS X server don't seem to use or test Xsan.

 

[dave_the_nerd]

It's a relic, from a time of Xserves and feeble attempts at enterprise market penetration.

I haven't ever tried it.

 

[Essence_of_War]

I like how in the server.app for xsan it says:

From Ars Technica's OSX Server review

And Apple will not actually sell you a computer with fibre channel...

 

[dave_the_nerd]

Yeah, not lately.

At my old job, we had some of the Apple-branded fiber channel drive enclosures. It's pretty old-school.

 

[rugby]

It's for a very specific purpose, if you need network storage to appear local. TB to fiber channel adapters exist, Apple NEVER sold computers with built-in fiber channel, it was always an add-on card.

So yes, you need fiber channel, yes you need 2 network ports per machine, and yes it's non-trivial to setup.

But once it's working it's beautiful when you need it.

 

[Childs]

We still use it using Promise Vtrak units, and a newer SAN as well using the Quantum storage appliances. In either case you still use Xsan. We dont really have a mixed environment, so it saves us money.

And Apple will not actually sell you a computer with fibre channel...

Apple never did. You needed add on PCIx/e fiber channel cards. Now you add Thunderbolt FC adapters.

 

[Childs]

It's for a very specific purpose, if you need network storage to appear local. TB to fiber channel adapters exist, Apple NEVER sold computers with built-in fiber channel, it was always an add-on card.

So yes, you need fiber channel, yes you need 2 network ports per machine, and yes it's non-trivial to setup.

But once it's working it's beautiful when you need it.

Dont forget the FC switches, additional ethernet switch or vlan, metadata controllers (macs). Then there's the storage too. I wouldnt say its necessarily hard to set up, but definitely cost prohibitive if you're a small shop, but reasonable when it comes to licensing since its been free for maybe the last 3 OSes.

I just wish they would include a free ISCSI driver in the OS. Bypassing all the FC stuff would increase adoption significantly.

 

[dave_the_nerd]

Dont forget the FC switches, additional ethernet switch or vlan, metadata controllers (macs). Then there's the storage too. I wouldnt say its necessarily hard to set up, but definitely cost prohibitive if you're a small shop, but reasonable when it comes to licensing since its been free for maybe the last 3 OSes.

I just wish they would include a free ISCSI driver in the OS. Bypassing all the FC stuff would increase adoption significantly.

If you've got installed hardware, that's one thing, but anything new... man, 10GbE iSCSI is awfully fast for the cost.

 

[Childs]

If you've got installed hardware, that's one thing, but anything new... man, 10GbE iSCSI is awfully fast for the cost.

Yeah, we already have the FC hardware, but getting management to pony up for 10GbE adapters for everyone, switches, and the iSCSI licenses is a tough sell. We evaluated 10GgE on a small scale and it performed well, but still slow compared to the FC stuff we already have. Another group went full in with 10GbE and iSCSI and it wasn't really reliable when scaled up. Talking maybe 200 clients. They tried using it in production and eventually they had to ditch it and roll back to FC.

They'll probably take another stab at it since they already have everything, but if Apple had their own iSCSI initiator it would go a long way towards stabilizing things. Just seems like Apple doesnt really want anything to do with anything related to the enterprise. Kinda surprising they still even support Xsan.

 

[rugby]

Dont forget the FC switches, additional ethernet switch or vlan, metadata controllers (macs). Then there's the storage too. I wouldnt say its necessarily hard to set up, but definitely cost prohibitive if you're a small shop, but reasonable when it comes to licensing since its been free for maybe the last 3 OSes.

I just wish they would include a free ISCSI driver in the OS. Bypassing all the FC stuff would increase adoption significantly.

True, I forgot all of that extra stuff. It's been a long time since I've looked at Xsan and I know people STILL swear by it for business use vs. AFP.

 

[rugby]

If you've got installed hardware, that's one thing, but anything new... man, 10GbE iSCSI is awfully fast for the cost.

10Gb iSCSI doesn't alleviate the issues with filesharing. Last time I checked you cannot mount an iscsi volume across multiple machines without wrecking your data. Has this been fixed recently?

 

[Essence_of_War]

10Gb iSCSI doesn't alleviate the issues with filesharing. Last time I checked you cannot mount an iscsi volume across multiple machines without wrecking your data. Has this been fixed recently?

I mean, iscsi is a block level protocol, so if you're mounting the same volume on multiple machines, aren't you kind of doing it wrong? :hmm:

You can certainly export a filesystem over 10 GbE using NFS, Samba, or AFP.

 

[dave_the_nerd]

10Gb iSCSI doesn't alleviate the issues with filesharing. Last time I checked you cannot mount an iscsi volume across multiple machines without wrecking your data. Has this been fixed recently?

No. That's not how SANs work.

Although if you use a clustered file system... but I don't think that's what you're getting at.