4 xserves, 1 xserve raid, 4 partitions, fibre channel - possible?

Is it possible to connect 4 xserves to 1 xraid that has 2 partitions for each side of the controller to all connect together using a fibre channel switch?
Thanks!
Tony

Hello Paul,
LUN slices are all equal sized - ie you slice it into two, three or four slices but they will all be equally sized. You can't slice off 1/3 of a RAID side and the leave the other 2/3s alone. (I guess you could slice it into three and then RAID0 the other two slices back together but that seems too tricky to be a good idea.) The advantage is that each LUN has a logical "name" and you can hardwire your fibre card to see only that "name" and there is zero chance of conflicting control of a slice.
If I understand you correctly you want to RAID 50 the entire RAID into a single big volume and the partition it up into smaller logical partitions. You will need to do the RAID0ing of the two sides before anything else because this will destroy the data that already exists on the RAID 5s. As long as you keep this in mind it is doable and you can then use fstab editing to control which Xserves load which volumes on start-up. Note that volume partitioning is not a set-up for a hostile environments because people will be able to do bad things if they are determined to do so - eg Using Disk Utility to force mount a volume they otherwise can't see and then play with it.
My question is "Do you really need a single large volume?" Alot of people do RAID 50 the unit into a single image but unless you need more than 3TB volume sizes for some reason or for HD video capture I personally don't see the attraction. You take RAID 5 which is pretty close to bullet proof but then you build it into a RAID 0. The data on a RAID 0 is susceptible to loss from breaking the RAID while two separate RAID5s (especially with hot spare drives) is about as close as you can get to rock solid in computing. If you're going to then divide it up and redistribute it anyway I'm not sure if the merging of the sides is necessary.
Only you can determine what you need but if you're not going to have a single >3TB volume I would go RAID5s on each side (7drives or 6+1spare ideally) and then either slice or partition up the volumes for the respective computers.
My $.02,
=Tod
G5/2.0x2, Dual XServes x2, XRAID, beige G3 501Mhz

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Xserve, G5, Xserve RAID and fibre channel question

hi guys,
I have a Xserve conneted to Xserve RAID right now. Is it possible connect G5 to Xserve RAID thru fibre channel ? thanks

>is it possible to do ?
Not in the way you describe, no.
The XServe RAID's 14 drives are connected to two separate controllers. Drives 1-7 are connected to the upper controller. Drives 8-14 are connected to the lower one.
If your XServe is currently connected to the upper controller it's talking to drives 1-7.
If you connect the G5 to the lower controller it will be talking to drives 8-14.
Therefore you cannot use this setup to backup the data via the G5.
At the very, very least you need a fiber channel switch so that both the XServe and the G5 can connect to the same controller. However, as Tod has already mentioned, it is tricky to get multiple machines talking to the same RAID drives while avoiding corruption (there's no concept of arbitration, or ways of preventing one machine from editing a file that's in use by the other machine).
You have two basic options - one is to implement XSAN, which will handle the arbitration issue, the other is to configure the G5 to mount the RAID read-only. This should prevent the G5 from modifying a file while it's in use by the XServe (which may be sufficient for backup purposes), but you may still run into issues when the G5 tries to backup a file that's actively in use by the XServe.
In all honesty, a better solution would either to get a SCSI card that works with the XServe and do it all there, or use file sharing between the XServe and the G5 and backup over the network - it'll be slower, but a lot more reliable.

Clarification on how to use Xserve Raid and Fibre Channel without xsan.

First let me apologize for not responding earlier to your response, I tend to get busy and then forget to check back here.
Tod, the answer to your question is No, only one computer is accessing the xserve raid files at any one time and that is via Fibre Channel. However I do have the xserve raids set up as share points via ethernet.
Maybe I should turn that off and only access the files with the one computer that can connect via fibre channel.
I never thought of that. I will try that while I await for your answer, thanks again.
Todd Buhmiller
I have the following setup:
Xserve: 2x2Ghz Dual Core Intel Xeon, 5Gb of Ram, Running 10.5.8 Leopard Server
Xserve Raid with firmware version 1.5.1/1.51c on both controllers, and
Qlogic Sanbox 5600
Apple Fibre Channel Cards in Xserve, and Mac Pro Tower; Apple 2 Port 4Gbs Fibre Channel Card
Mac Pro Tower-Quad Core Intel Xeon 2.8Ghz, 16Gb of Ram, Running Snow Leopard 10.6.4
Here is the problem.
The directory for the xserve raids keep getting corrup, and I use disc warrior to rebuild them. Is there a way to keep the directories from getting corrupt? I am a few pieces of equipment before I can build an Xsan as that is the ultimate goal, but until then, I just need to be able to have the raids funciton as storage without having to rebuild the directories all of the time.
Anybody have any suggestions?
Thanks
Todd Buhmiller
Widescreen Media
Calgary, Alberta Canada
Tod Kuykendall
Posts: 1,237
From: San Diego
Registered: Oct 11, 2000
Re: Xserve Raid Mounts, Corrupt Directory tired of rebuilding directory
Posted: Jun 27, 2010 1:25 PM in response to: Todd Buhmiller
Are multiple computers accessing the same data on the RAID at the same time?
If so then NO. This is the source of your data corruption and I'm surprised if you were able to get all your data back every time if this is how you've been running your system. Each fibre channel assumes it has full and sole control of every volume it has mounted, no data arbitration is practiced and data corruption will occur if this assumption is wrong.
The only way this set-up will work is to use partitions or LUN masks so the volumes are accessed by one computer at any time. As long as one computer relinquishes control before another mounts it you will dodge arbitration issues but this is a dangerous game. If you screw up and mount an already mounted volume - and there is no easy way to tell if a volume is mounted - corruption will then occur. Sharing data simultaneous at fibre speeds is what XSAN does and to do this you need it.
HTH,
=Tod
Intel Xserve, G5 XServes, XRAID, Promise

+The xserve raids will mount automatically to any computer that I connect the qlogic fc switch to+
This is source of the corruption to your data. Any computer that attaches to a drive/partition via fibre channel assumes that it alone is in control of the drive and data corruption is inevitable.
+Is that the issue, should I disconnect the xserve from the fc switch and leave it connected via ethernet?+
Short answer: YES. The ethernet connections are fine because the server is controlling the file arbitration through the sharing protocol. Fibre channel connections assumes complete control over the partition and no arbitration of the file access is performed. It's like two people independently driving trying to drive the same car to different locations.
Depending on your set-up it is possible for the two machines to see and use different parts of the Xserve RAID storage but they cannot access the same areas without SAN doing the arbitration.
Hope that's clear,
=Tod

Parallel SCSI, Hardware RAID, SAS, Fibre Channel. - What's included?

If I get the $2500 vanilla (nothing added) Mac Pro...
Do I get any of these?
Parallel SCSI, Hardware RAID, SAS, and/or Fibre Channel?
Just curious. I know what they do, but I'm just wondering if it's included with the Mac Pro with its price tag.

None are included.

Easiest solution for adding Fibre Channel Tape Backup to Xserve RAID setup

I'm interested in getting a Fibre Channel LTO-3 tape library such as the Exabyte 221L for my Xserve RAID/Xserve G5 setup. I realize there are SCSI LTO-3 solutions that are less expensive than FC, but I'd prefer not to have to add a SCSI card to my Xserve, mainly because I'd have to pull the video card and run the server headless (horrors!). However, I understand that I must get a Fibre Channel switch to allow the LTO library, the Xserve, and the Xserve RAID to communicate... you can't just daisy chain FC devices. The least expensive switch I can find is the new QLogtic SANbox 3050 for about $1800. For my situation, in which these will be the only FC devices I'll probably ever use, does this switch sound appropriate? The specs on the switch can be found here: http://www.qlogic.com/products/sanbox/sanbox_3050.asp.
Xserve RAID & Xserve G5 Mac OS X (10.4.5)

For simple environments like yours, it's trivially easy. You must plug everything in, and you're good to go... as simple as a network switch.
Now if you start adding multiple hosts (i.e. plug in a second Xserve or G5), you need to be careful, because in the default configuration everything is "wide open," so every device can see every storage LUN. This would actually be problematic, as systems could (actually, would) corrupt each other's storage. When you get to this point, you'll need to look at either zoning the ports on the switch, or using LUN masking on the Xserve RAID to allocate specific pieces of storage to specific hosts.
But for now, just get the switch, plug everything in, and you're off.
BTW if you mark "answered" for me, versus for the thread overall, it helps me out a bit in this forum ranking system, whatever it is.
Cheers.

Xserve Raid will not mount - fibre channel link down

I came back from being out of town and my Xserve is running, but will not mount on the G5 tower via fibre channel. It was powered off and up again and still nothing. Apple tech says to reset raid controllers, however, I have sensitive data on the drives and lots of video/FCP projects on there. It has just run out of warranty and now asked to pay $199 per incident to get any help. I will gladly take any help.
Read the boards, ran Disk Utility and still did not show up.
Also, told the fibre cables tend to "burn out" but have yet to spend money if this is not the problem.
Thanks.

Resetting the controllers is non-destructive. However, if you power-cycled the array, that should take care of it.
told the fibre cables tend to "burn out"
I've never experienced (or heard of this) myself, and have never had a problem on any of my arrays, some of which have been running for years with zero problems. Of course, environment (especially heat) could play a part, but it seems a little bit of a stretch to me.
Does RAID Admin have anything to say about the RAID?

Fibre channel lights on Xserve RAID

I have a G4 Xserve 1.33Ghz connected via Apple's Fibre channel card to a Xserve RAID. 3 drives installed, RAID 5 and a hot spare. The drives are installed in bays 1-4, but the fibre channel activity light is off on the left one, but active green for the right one. There are no drives in bays 8-14, the RAID controller is active.
Surely the left light fibre channel light should be active, and the right one off.
Any ideas, thanks

Hmmm.
I recall the lights on the RAID might be the reverse of what's expected? I'm not 100% certain here -- this may be normal behavior.
Can you see the LUNs in Disk Utility? That's where you can usually check. You may also want to try rebooting once -- just in case the LIP message sent when the RAID came online was ignored.
As for the RAID initializing... once you're above 2% or 3% or so it should be visible from the host... the default is to use RAID Now background initialization which means the volume is available for use (and safe to use -- data is protected), though a bit slower while the initialization completes. Initialization takes a long time -- ~30 hours or so.

Xserve RAID Fibre Channel Lights pegged until disk activity

We are having some issues with an Xserve RAID connected to a G5 Xserve running 10.4.8 Server. The Fibre Channel lights on the front are constantly maxed out, but whenever the disk are active the lights die down only to peg again when activity stops. Needless to say, we are having SEVERE access speed issues. Any ideas?

This can happen in a protected RAID set (i.e. RAID 5) if a single raid member drive pops offline and back on again, since the RAID set has to re-build itself from the parity data in that case.
It also happens after creating a RAID 5 volume, as the creation usually takes a few days (assuming you used the 'RAID Now' option), and so you'll see the blue lights.
It also makes sense that the blue light 'spiking' would drop when you do a read/write, as the initialization process has to pause to handle the disk activity.
Are either of these the case?
We are having some issues with an Xserve RAID
connected to a G5 Xserve running 10.4.8 Server. The
Fibre Channel lights on the front are constantly
maxed out, but whenever the disk are active the
lights die down only to peg again when activity
stops. Needless to say, we are having SEVERE access
speed issues. Any ideas?
MacBook Pro Mac OS X (10.4.8)

Xserver Fibre Channel with tape backup issues?

Is this correct, that OS X 10.4.9 and 10.4.10 has a fibre channel issue with external tape drives (as well as SCSI drives)???
And this is to be fixed in 10.4.11? Do we have a time frame when we will see 10.4.11 to fix this major snafu?
I'm going to decide on a different server (in the meantime) and do net backups if this is the case. But what about others that run backup off the server, attached to an Xserve RAID?
BTW, I contacted BRU support with query on their software...I give kudos to them. Their support is spot on!
Message was edited by: Eddie Ski

Retrospect is just hideously, egregiously out of date and I don't think EMC gives a d*mn, at all.
Even pre-Intel, it will happily LOCK up your server while failing to properly time out when trying to talk to a tape library. It's well-known, Retro + Tape Library = h*ll on earth. And the fault lies squarely with Retro because something like Bru and other more expensive software does not have the same issue.
So let's just make sure -not- to judge "SCSI" isues in OS X based on the ungodly-awful behaviour of Retrospect. Might as well do automobile performance tests using only amateur drivers ; )

Super Slow Performance with Xserve RAID / Promise Fibre

Hey guys,
I am experiencing a strange thing on both 10.5.8 and 10.7.5 servers (yes these are in the process of being retired). They are sharing out either an Xserve RAID or Promise Vtrak with OS X Server.
We have the fibre channel card and the storage attaches to there and they appear mounted on the desktop.
The problem we are having is that whenever OS X's file sharing is enabled these volumes run incredibly slow! I did a clean install of OS X 10.7.5 on an entirely different machine and it was still bad. All of my tests show that when you turn off file sharing, both AFP and SMB, the performance goes back to normal -- so what can we do here??? These are file servers, so that's pretty much the only thing that needs to work.
Thanks,
Andrew

Slow/poor RAID performance can be down to a number of things. Some of which are easier to check than others.
Some easy things to check are:
How much data is stored on the RAIDs?
Performance really drops off alarmingly once the RAID gets to 85% full. For a 1TB RAID this means you need to keep at least 250GB of free disk space at all times otherwise you will get the poor performance you're seeing. Once it gets to 86/87/88% full performance can drop alarmingly. Yes those few percent points can make a big difference.
How is the data stored on the RAIDs?
Having thousands and thousands of single files stored loosely on the RAID or within one single folder is not a good idea. The Finder can be and is fairly inefficient at drawing the icons for those files that are presented to network users accessing the share point(s). This can/and is perceived as very slow performance as you're viewing the files over a network connection. One way to overcome this 'feature' is to organise the data into logical folders/sub-folders and/or shares.
Are there problems with the file/directory structure of the RAIDs themselves?
Use DiskUtility (or better still DiskWarrior) to repair any issues (generally built up over a period of time) with the storage disks you have. You can't repair permissions using DiskUtility or anything else on a non-OS bearing drive. Don't forget to do this also for your System Drive (which can have its permissions repaired) as well. This will mean the server being off-line for a time whilst the system (OS) drive is being repaired. Before doing this step I would make sure you have a current and effective backup of your System/Server OS as well as all data stored on the RAIDs themselves. Hopefully you should be doing this for your data already?
To understand Disk Utility's repair permissions feature please read Apple's support document here:
About Disk Utility's Repair Disk Permissions feature - Apple Support

Fibre Channel Link light off on Xserve

I noticed a few days ago that the lower Fibre Channel link light and Activity lights are no longer working on the lower unit on my Xserve. So far I tried unplugging and replugging the Fibre cable but that didn't help.
THere are no warning lights lit on the Fibre card on the back of my G5, and from flipping through the Xserve manual, it looks like all those lights are correct also.
We recently had the network rewired and since then I haven't been able to access the RAID Admin to see what's up. I may have to reset the controller though.
If you have any advice on where to start troubleshooting, or settings to check once I get the RAID Admin working I'd appreciate the advice, thanks!
PS: I have installed the Xserve Driver Update 1.0

Everything seems to be working normally. I'm mastering off the few projects I just finished, and I'm able to play back to streams of Uncompressed 10 bit SD so far so good. Although the one working channel seems to be working a bit harder than usual
The Xserve RAID is hooked directly to my powermac G5 via Apple's Fibre Channel Card. I talked to my boss who has been working wit the network people and said the IP address should be the same, and it should be picking up DHCP. From your post it sounded like there may be a setting in RAID Admin for this? I'll check after I finish Edit to Tape
Think of my calmness this way: If the front of your car is hanging off the edge of a cliff, the last thing you'd want to do is make any sudden moves!

Xserve RAID with fibre switch and windows

I have a customer who potentially is looking at an Xserve and RAID using a fibre switch with a couple of G5s with fibre cards for speed. They also have a Windows machine that they need to access files, but speed is not an issue. Will the Windows machine be able to see the RAID if it is shared by OS X Server via ethernet or does it need a fibre card? Thanks in advance for assistance!
Mac OS X (10.4.3)

You can turn on Windows (SMB) sharing, or you can connect it directly via fibre channel. Note, if you connect it to the fibre, you can't have it access the SAME volume at the SAME time as the Macs are accessing (heck, you can't have the Macs access the SAME volume at the SAME time without software either), without Xsan and the StorNext file system.

Intel Xserve + Xserve RAID + SCSI

I have a requirement for an Intel Xserve system that I can connect an Xserve RAID and SCSI tape autoloader to. It seems that Apple won't let me configure a system with a SCSI card and a fibre channel card in it at the same time, and repeated phone calls to them have yielded precisely nothing (very disappointed with the lack of professionalism and knowledge displayed by the Apple sales and tech staff on this matter).
Can I have such a configuration? It seems that I can only fit a fibre channel PCIe card in expansion slot 1 as it is too long to fit in slot 2 which is limited to 6" long cards. I've seen that Atto do PCIe SCSI cards but there is no mention on their site about whether they will fit/work in slot 2 of an Xserve and emails to them have gone unanswered.
If anyone has any info on this, or could point me in the direction of the info, I would be very grateful. Or if what I want isn't possible, ideas on how to back up a 7TB array without direct attached tape storage would also be appreciated.

Actually, having just looked at the store, Apple
don't seem to offer any PCIe SCSI cards, just a PCI-X
one with a PCI-X riser. Would this configuration stop
me using a PCIe card in slot 2?
Avoid the Apple BTO SCSI card like the plague. It's junk.
It's really a rebranded LSI Logic 22320. Ours never worked
right in our Xserve G5; we replaced it with an ATTO UL4D and
all of our problems went away. The right card for the intel
Xserve is the ATTO UL5D or UL5D low profile (both are PCIe).
Link is here:
http://www.attotech.com/hostadapter.html
The Apple-rebranded LSI Logic 22320 sits on a shelf gathering
dust.
Russ
Xserve G5 2.0 GHz 2 GB RAM Mac OS X (10.4.8) Apple Hardware RAID, ATTO UL4D, Exabyte VXA-2 1x10 1u

Problem with fibre channel card and raid system after upgrading to 10.4.7

Hello, I have a problem with our Xserve G4 DP. After the installation of 10.4.7 everything works fine exept our fibre channel card. This card is connected to a Hitachi Raid System which worked fine over a year. But after the update the volume was no longer mounted. I even reinstalled the server to 10.4.4 and no sign of our raid volume. Using the apple fibre channel utiltiy 2.0, I see that there is a connection - but still the raid volume is not mounted. When I restart the server the lights on the back of the card are shortly flickering and sending some packets to the raid system but that´s all. Has anybody an idea?
Greetings from Heidelberg
Klaus
Xserve G4 DP 1 GHz Mac OS X (10.4.6) Mac OSX Server 10.4.7

You could re-update, by downloading the 10.4.7 Combination Updater from Apple.

Xserve G5 RAID question

Can you use the Xserve G5 PCI RAID controller and the Xserve RAID Fibre Channel controller in the same Xserve? Thanks in advance.

Yes.
The XServe has two PCI slots. The RAID card must be installed in the lower slot, but that leaves the upper slot available for the fiber channel card.
Note, though, that when running with two PCI cards installed, the PCI bus runs at 100MHz, not 133Mhz, potentially degrading throughput. Whether or not the difference is noticeable will depend on your usage pattern.

4 xserves, 1 xserve raid, 4 partitions, fibre channel - possible?

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