Basic Xserve Raid Set Up Help

Please excuse the newbie question I have looked on the forum and cant quite find the info I need.
Can someone give me a step by step guide to setting up an Xserve raid please.
We have 2 G5s each running Final Cut Pro. We have just purchased a 7TB Xserve raid from Apple Refurb.
We would like a very simple set up where each G5 uses half of the Xserve. We do not have a fibre switch at this point - we do not need to share media however we will add this later.
So our initial requirement is a very basic 2xG5 each with a single fibre connection to each half of the Xserve. Sounds easy but . . .
We connected one of the G5s to both fibre ports in order to just set up the drives, once done we will simply disconnect one fibre cable and connect to the other G5.
We thought that the Xserve would be pre-configured to raid 5, which is what we would like to use. However upon connection there was a message that the drives were not readable and needed to be initialised. (the standard apple message if drive is not formatted)
We ignored this message and went to the drive utility to see if we could mount the drives and although it sees two drives, (each just under 3TB) as you would expect, it seems they are not mountable. (Since the drive utility saw 2 drives I assume that they are preconfigured to a raid)
So I looked in the raid utility and the only option is to 'add system'. If I click this I get a dialogue box asking for address and password. I understand the 'private' 'public' password and used the host computers IP address as there is no network.
I thought that this would take us through to the set up that allows you to create arrays and raid types etc.
So I am a bit stuck.
If the drives are preconfigured to raid 5 how can I mount them ? as that would be the simple config we need.
Or do I need to start from scratch ? Hence my request for a step by step guide.
best wishes and thanks for your help in advance
Neil

I can't speak to exactly how the Xserve RAID comes from refurb but in general there are two steps to using the RAID.
1) Create the RAIDs on the machines. (This takes some 30+ hours.)
2) Format the new volumes. (This takes 2 minutes.)
Assuming the RAID came configured RAID 5 on each side and *you didn't shuffle the drive order* then they should still be configured and available that way. Apple doesn't assume that you are going to use the Xserve RAID with HFS+ formatting - they don't even assume you're going to use it with a Mac so I think the volumes are probably unformatted. My guess is that you are between steps 1 and 2 and you will need to choose the volumes in Disk Utility and format them to HFS+ (but probably not journalled if you are doing video work) and partition them.
You can get and set the actual RAID information using the Java tool RAID Admin.
You can (and should) connect to one of the ethernet ports on RAID unit, but the computer you connect will need to be in the same IP range (probably 169.254..) to get to the first time and run RAID Admin. This is how you can set-up, tweak and check the status of your RAID through software. This is also where you can set the IP of the RAID to be more in-line with your computers local network if you're using something different.
HTH,
=Tod

Similar Messages

Xserve-RAID set up

I am a photographer and I am setting up an Xserve RAID system that I have had for a little while to store my photographs. Can anybody help suggest the best RAID level. My sense is telling me that for photographs I need to Mirror so Level 1. I have 7 drives so can I mirror a set of three drives which takes up 6 drives and have one drive left as a "hot Spare"?
Thank you for your time....

Why do you want to mirror your storage?
Without more information I would suggest RAID 5 by reflex. It will give you the most storage - a 6 disk RAID 5 will give you disksize* 5 storage and it will protect your data if a drive fails. And if a drive fails the 7th disk hot-spare will be automatically be used to rebuild the RAID data.
You will not be protected if more than one drive fails simultaneously - that's what back-up is for. Mirrored RAID is NOT a back-up plan. It will not protect you against disk corruption or accidental deletion (that will be mirrored immediately) nor does it protect you against water being poured on the RAID box or someone stealing it or fire or whatever... Only back-up protects you against these things.
There are legitimate reasons to run mirrored RAID but back-up is not one of them. If your reasons are sound (and you are doing back-up in addition to mirroring) then your plan is certainly doable but make sure your reasons are the right ones.
HTH,
=Tod

Xserve Raid Crash Course Help Needed

We received two Xserve Raids loaded with 250 gig hard drives, fiber Channel Cards, all cables etc. We are a very small animation company. Is there any manuals or web pages to help us get started and learn how to set this equipment up? Apple manuals do not tell much, Thanks

Hi
http://manuals.info.apple.com/en/XserveRAID_UserGuide.PDF
http://support.apple.com/kb/HT2760?viewlocale=en_US
http://support.apple.com/kb/HT2758?viewlocale=en_US
http://docs.info.apple.com/article.html?artnum=51795
http://manuals.info.apple.com/enUS/RAIDAdmin1.2121406.pdf
http://www.apple.com/support/xserveraid/
I can only speak for myself but all of the above is what I've used and I've not had too many problems. It's advisable to purchase a UPS if you haven't already got one.
The host machine does not have to be an XServe.
Tony

Expanding XServe RAID set - stuck at 99%

We have an XServe RAID. One side had a RAID 5 set consisting of 6x500GB HDD's. We came to within 60Gb of filling it up and therefore initiated expansion of RAID set to 7th drive on Saturday. This was progressing 1% / 40 mins. We calculated that it would not complete before Monday when users would start hammering it, but after testing it, it seemed to be working perfectly fine while expanding. Writing/reading speed did not seem to be noticeably affected and we decided that all seemed well.
Monday started off well. Not not a single user noticed reduced speed or any other problems - This was until about 3pm when the file server hosting AFP & SMB crashed! Not good! Upon restart, the RAID set would not mount again.
RAID Admin shows the expansion at 99%.   I was hoping that the RAID set could be mounted again once it completed to 100%, but it does not seem like this will be happening anytime soon - it has been stuck on 99% for about 6 hours now and I don't know when/if it will ever finish. (Previously 1% every 40mins)
The fibre channel preference pane shows "Link Established" to the XServe RAID, similarly the RAID Utility shows "Link Up" to server. The RAID, however, does not appear in Disk Utility - even after restarts.
Does anyone out there have experience expanding a RAID Set on an XServe RAID? Does it usually stall at 99%? How long does it take to finish once it has reached 99%?
Is there anything I can do to try and get the RAID Set mounted before it finishes its expansion? It's now 8pm here (GMT+8) and users have finished for the day, but we only have about 12 hours before it needs to be up and running again!
I am out of ideas to try. Any help would be greatly appreciated.
Thanks

Curiously, more output from the above-mentioned 3rd party tool gives:
$ ./xserve-raid-info
Use of uninitialized value in string at ./xserve-raid-info line 655.
Use of uninitialized value in string at ./xserve-raid-info line 655.
Use of uninitialized value in string at ./xserve-raid-info line 655.
Use of uninitialized value in string at ./xserve-raid-info line 655.
Name: Xserve-RAID
States:
RAIDs: optimal
Components: optimal
Fibre Channel: optimal
Network: warning
Warnings:
The top network link is down.
Upper Controller Info:
Status: ok
Firmware Version: 1.5.1f2/50
Up Time: 262 days 1 hr
Temperature: 75.2 deg F
Write Cache: disabled
Prefetch Size: 8 stripes (512 KB/disk)
Fibre Channel: link up
    Topology: arbitrated loop
    Speed: 2Gb/sec
Network: link down
    IP Address: 192.168.30.11
    Subnet Mask: 255.255.255.0
Lower Controller Info:
Status: ok
Firmware Version: 1.5.1f2/50
Up Time: 262 days 1 hr
Temperature: 82.4 deg F
Write Cache: disabled
Prefetch Size: 8 stripes (512 KB/disk)
Fibre Channel: link up
    Topology: arbitrated loop
    Speed: 2Gb/sec
Network: link up
    IP Address: 192.168.30.21
    Subnet Mask: 255.255.255.0
In RAID Admin, I've added systems using 192.168.30.11 (supposedly - link down).
I can NOT connect using 192.168.30.21 - it says incorrect password even though I know I am entering the correct one...

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

XServe RAID connected to Video Editing Station via Ethernet -Fibre question

I'm looking into switching from ethernet connections from our three desktop systems to the Xserve Raid set up we currently have to fibre. I can't seem to get a clear answer as to if it is possible to just add the cards and cables to the switch we have or if I would have to go the XSAN route in order to have fibre as the direct connection to the RAIDs...
I'm a photographer, not an IT person so please feel free to speak down to my level... : )

In theory GigE ether allows for 1000 Mb/s with a theoretical throughput of 125MB/s and 2GB Fibre is about 70% faster than that at 1700 Mb/s with 212.5 MB/s of throughput.
Now the big differences are that TCP/IP is not optimized for steady stream delivery and you're sharing the connection over a single server that works to schedule fairly and parcel out resources among users. Fibre is a single connection designed to stream data to you so you get to use a lot more of your fibre bandwidth then you do over GigE. At this point the 7 drive array is not able to saturate the fibre so you won't test the theoretical limits of the bandwidth because of the headroom in the system. At max throughput I would expect the drives are putting out something in the range of ~100-130MB/s so even with a direct connection that is your max.
If I was forced to guesstimate I would think you would be getting somewhere between 3-4x faster throughput over fibre. You're certainly more likely to hit the upper-limit of max drive output over fibre so if you say you're getting 100 MB/s over fibre and 25 MB/s over ether then that's about right. If your ether is <20MB/s then it's theoretically possible you could see a 5-6x improvement. Maybe you should test your ether with some transfers and see what your through-put is to make your own estimations.
If an 80GB file takes 55 minutes that then that's about 25MB/s. If you could bring that down by a factor of 3 then that would be 36 minutes of saved - and hopefully billable - time. But if you're getting 40 MB/s a 80GB file would take 35 minutes and then your max savings is probably 15 or 20 minutes and it becomes less compelling depending on how many times a day you do it.
+You've been very generous with your time answering all of my questions, thank you again.+
You're welcome, hope it all works out for you,
=Tod
PS Remember that large single files get much better throughput than many small files on transfer tests. Also you might want to do your own math on what time = what throughput too. Those numbers were off the top of my head.

Help on Setting up Xserve Raid

In our department we have three MacPro's, and one G5 Quad. We want to add an Xserve Raid to store and serve hi-res image files to each workstation. There is a company wide network (intranet) to which we have aready added the workstations, along with printers, however our IT people do not support the Mac platform and we are on our own as far as getting the Xserve Raid in the mix.
I am looking for advice as to how best to set it up and what sort of addition hardware or software we might need.
MacPro Mac OS X (10.4.8) 4gig ram
MacBook Pro Mac OS X (10.4.7)

I'd concur that it's generally a bad idea to use a production machine as a file server. OS X is fairly stable though. Worst case will likely be you'd loose the file server if an errant application hung up the finder. I can't remember the last time I've had an OS X box lock up solid.. though they do occassionally become unusable from the console.
If you're really budget constrained, put it on the tower. Just be careful about the Fibre controller. Apple has made PCI-X and PCI-E versions over the years.
As far as whos controller to buy, Apple's isn't just competative, it's a steal. It's a 2Gb/channel controller and it runs over Copper (not real fiber optic). You can find cheaper FC cards but they are 1Gb per channel. There are also 4Gb per channel cards.. these will generally fall back to 2 or 1 Gb per channel but they are VERY expensive. FC has come down a lot but it's not unusual to find cards with the same specs as Apple's for twice the price. At least one of our sys admins puts Apple's cards in his x86 Linux servers because they are the cheapest cards he can get. (they also work in Windows 2003 machines since they are just rebranded cards from another vendor.. we're running one in a Dell next door.. as a test for the XSan we're building).

Problem with raid set on xserve

Hi to all!
I hope you can help me with a big problem that I have with a Xserve of the work.
Yesterday afternoon I come to the work and my partners mentioned to me that the web pages were not going. I tried to connect with ARD but he was not answering. I had to move to the building where the server is racked and when I connected a monitor a it was showing me a folder icon with an interrogation icon.
Since this had happened to me in my Mac of the office once, I initiated from the installation DVD to see if I could repair permissions and/or the discs with the Disk Utility. For my surprise (and terror) does not show any volume or disk except the DVD.
I got into the RAID Utility in the menu and there I could see the discs but the RAID Sets does not appear... We had mounted since we install the machine a raid 5 with 3 discs and 2 volumes on this raid set.
Then, from the Terminal, doing "diskutil list" it's show no volume on any disk.
I suppose that something has happened with the volumes and the raid cannot be mounted...
Is there any way to mount the volumes again? Something similar to the "fixmbr" that I believe that there are in others OS to restore the volumes tables...
Is there any way to mount again the RAID without losing the information from the discs?
Do you know that can be happening?
PS: It is a Xserve of the last ones, with Mac OS X 10.6.8. I have already tried to reset the PRAM and it keeps on doing the same.

The Server Monitr does say anything. It doesnt pick up any server. I tried to add the XServe in the Server Monitor, but it keeps waiting for a reply after I have put in the username, password and IP address.
It is an XServe with a Mirror software RAID on the 2 x Internal Hard Drives within the XServe
I am not using the SAN software
There have been reports of fault latchs on the Apple Drive Bay Modules. Do you think this could be causing the units to dismount?

Proper procedure for replacing drive in Xserve RAID RAID5 set

I've got a five-drive RAID-5 set (with a sixth hot spare) in an Xserve RAID running the 1.5/1.50f firmware. One of the drives in the RAID-5 set has an amber/orange status light on and has been getting occasional errors like to following:
Timestamp: 11/10/10 10:34:53 AM
Priority: Warning
Controller: Upper Controller
Type: 112
Event ID: 1000
Event: Disk 5 Reported An Error. COMMAND:0x35 ERROR:0x10 STATUS:0x51 LBA:0x19B80
Description: The drive reported an ATA error. This is a failure in the communication from the RAID Controller to the drive.
I have double checked the drives in RAID Admin and, as the drive is only in a warning state, the hot spare has not been pulled into the RAID set yet. As this is an old drive, I'd like to replace that particular drive first. I have a current, full backup of the data, but want to make sure I understand the process correctly.
I understand the "Installing or Replacing an Apple Drive Module" section of http://manuals.info.apple.com/en/XserveRAID_UserGuide.PDF, but it and RAID Admin's built-in help don't describe what will happen when replacing a drive in a RAID set that has a hot spare. When I pull out the drive and replace it, will it correctly use the newly inserted drive or will it use the hot spare? If it uses the hot spare, will the hot spare revert back to a hot spare once the new drive is inserted or will it permanently become a member of the RAID set and need to be moved to the original drive's slot? Or, should I just pull out the hot spare, pull out the failing drive, and pop the hot spare into the failing drive's slot?

Hello, makkintosshu, and welcome to the AppleBoards,
If you pull out the drive the RAID should/will immediately start rebuilding using the hot spare. The hot spare will become a new permanent member of the RAID and the new replacement drive will become the new hot spare. The physical slot locations of the drives don't matter you can build a RAID from any combination of drives as long as they are on the same side.
If you pull the hot spare and then the failing drive the RAID will wait for a new drive before taking action. I find it hard to recommend this course of action unless there is a really good reason for you not wanting the hot spare to become part of the RAID. Rebuilding is going to take a good long while and you want it to start as soon as possible - as long as the RAID is not rebuilt your data is at risk. Letting the RAID rebuild hang as you physically swap out the failed the drive strikes me as bad idea that needs a really good justification.
HTH,
=Tod

Newbie here...Need help for XServe RAID w/ XSAN in Vid Editing environment

We're establishing an XSAN environment for video editing work flow. We're not new to SAN technology or video editing, but we are new to Xserve RAIDs, XSAN technology, and marrying them together in a production environment.
We have an XServe RAID at 14x750GB configuration. 1 Xserve metadata server, 1 Xserve Quicktime server, and 4 editing stations (2 MacPro's, 2 G5's) that are in the fiber channel fabric. Each machine has dual channel 4GB cards.
My PLEA for help concerns any advice this community can offer on RAID configuration, and XSAN configuration to achieve maximum performance. Settings, configurations, etc.
XServe, XServe RAID, XSAN, MacPro, G5 Mac OS X (10.4.9)

Were on the same boat but more like a life jacket
We only need the Fibre for back-up.
We have a single Avid Adrenaline on MacPro.
One Xserve that basically acts as a server for fonts, audioclips, photocatalog and minor back-up via gigabit ethernet.
Three G5s/MacPro/PC with 2/4GB FC installed.
One 10.5 TB Xserve RAID.
Last but not least a QLogic 1400 SAN box for Fibre.
Nothing is installed yet as were waiting on our Apple rep for some answers with Xsan.
Were not serving anything as far as external network and everything stays within the confines of our studio.
My question is that are we missing anything other than maybe getting more ports on the SAN.
We can live with a few workstations in the fabric.
Thanks in advance
XServe Mac OS X (10.4.6) OSX Server

Looking for some ideas for setting up and xServe RAID

Everyone,
Here is what I would to do. I have a new xServe and 7TB RAID. I would like to set all of my end users up with Portable Home Directories. They all have laptops and I would like to use their PHD as my backup source. I would set them to sync in the background a couple of times per day and then write to tape at night.I have about 60 end users. I would also like to use the same xServe and RAID as my Kerio mail server and mail store. What I am looking for is some ideas of how to go about setting up the RAID. I was orginially thinking of setting up as one big RAID 5 using all 14 drives. What I would like to know is what is the number of drives that would need to fail that would render the RAID unrebuildable? I am now thinking about splitting the RAID into two 7 drives in RAID set up as RAID 1+0.
I am not sure if I phrased a lot of this currently, but here is quick recap of what I would like to know. What would be the best way to set up a 7TB RAID to store PHD and my Kerio mail store that provides me the most redudant and fastest acccess.
Thanks in advance.
Sincerely,
Daniel Krajc

Daniel,
I'd suggest a 6 disk RAID 5 plus a hot spare for each side. It will give you about 2.4 TB capacity per side (4.8 total), and it can tolerate 2 drive failures per side without losing data, provided there is sufficient time between failures for the RAID set to automatically rebuild on the hot spare. This window is 8-12 hours.
Note with Xserve RAID the two sides are totally independent in the data path -- it will look like 2 separate LUNs. If you want to combine these at the host level, as RAID 0 or RAID 1 to look like a single volume, you can. But the Xserve RAID will not combine them itself... the RAID controllers are independent... it might as well be two separate RAID volumes in the same chassis.
I assume you'll plug this into an Xserve that is serving as an Open Directory server and a file server?

Xserve raid midplane(?) troubleshooting help

Hi,
I just inherited an XServe RAID with 12 180GB drives. My question is thus:
If I put the single RAID controller in the top slot, It recognizes all drives on the left side of the RAID, which is expected
If I put the single RAID controller in the bottom slot, it does not recognize any drives in any slots even if I swap those drives from the left side to the right (to rule out 5 bad drives.
I have two empty sleds that are on the right side of the RAID as well.
I am guessing, having never owned one before, that this is likely a problem with the midplane. Is there a way to troubleshoot the midplane? I very quick inspection, didn't reveal anything that was obvious. I plan on doing a more thorough inspection over the weekend.
I am also making the assumption that I do not have to have a controller in the top slot for the bottom controller to work since the top controller works without having a controller in the bottom slot.
Any help/insight would be appreciated

LIttle Update in case it would help someone with more knowledge of this than I:
When the Controller is in the lower position:
or
which I find interesting since I don't have an upper controller installed and the cooling modules both show as missing even though they exist (though 1 is failed).
If I look at the other tabs:
Info: Shows only Name: XServe RAID and Power State: On
Arrays & Drives: Shows Not Installed for all drives on that side of the XServe RAID
Fibre Channel is blank as I don't currently have it connected to my XServe
Events shows nothing of significance to me other than all disks online
When the controller is in the upper position however:
I am curious as to why the RAID controller shows as present in both slots when it clearly is not however.
Hoping it was just a cable from the midplane to the unit, I swapped cables this morning hoping for a failure, but did not get such failure, so I have ruled out the cable. The Controller seems to work when it is in the top slot, so I think that the controller is likely good as well. So I guess I can sum it up as:
Power supplies: Good x2, shows a green light in either slot, swapped in testing
Batteries: Good x2; Swapped in testing, Swapped in testing, works in upper slot, does not in lower slot
Cooling Unit: Good x2; Swapped in testing, works in upper slot, does not in lower slot
Controller: Good x1; works in upper slot, does not work in lower slot
Which leads me back to the midplane as there isn't much else inside this unit that I can see that could go wrong. Does this sound like an accurate assessment? I ask because I want to be confident I have found the issue prior to ordering a new backplane.
Once again, thanks in advance for any information.

Degraded RAID set help

Hello Support Community,
I have a 4 bay RAID set that all of a sudden is showing as degraded. I have two pairs of disks each striped, and then have those two pairs mirrored. Not sure if this is a correct RAID format, but it is what it is right now. So both striped sets say online, with no problems, but my mirrored set of those two pairs shows that it is degraded. See below.
Any thoughts as to what might be happening? I have the options set to automatically rebuild the RAID. How do I know this is happening? How long should I expect this to take? It's a 4TB raid in it's current config, and there is about 3.7TB of data on this RAID. I have everything backed up in two other locations. Am I better off starting from scratch? Or should I just let this thing run for 2 weeks and see what happens? Any help would be greatly appreciated.
Thanks
Dave

No, I was doing all of this in disk utility. I left the arrary running overnight, and it's back online now. Not sure what got screwed up.
Thanks

Upgrading Xserve with RAID set

Hi,
I have been asked to upgrade a copy of Server 10.3 to 10.4. I don't like upgrading, so will do a clean install and then restore all of the SA and WGM data back into the server. Here is the question:
The XServe has 3 bays - bay 1 has the startup disk and bay 2 and 3 have a mirrored RAID set. Is the RAID config data held in the OS, so if I reinstall the system will the configuration data for the RAID set be lost and will I have to re-RAID the server? Or is the config data stored on the drive and so a re-install won't affect the RAID set?
Many thanks,
JS
iMac G5 17" 2 Ghz, 1 GB RAM, 600 GB HDD Mac OS X (10.4.9)
iMac G5 17" 2 Ghz, 1 GB RAM, 600 GB HDD Mac OS X (10.4.9)
iMac G5 17" 2 Ghz, 1 GB RAM, 600 GB HDD Mac OS X (10.4.9)

I would like to know if the RAID 'config' data is
actually written onto the drive or is stored in the
OS. I first thought it would be stored in software
because Disk Utility uses software RAID, but then
again a single drive has the partition data on the
drive.
James,
If you think about it a bit, software RAID information has to be on the drive because the volume becomes a RAID before a filesystem is created and before an install is done. Likewise, a hardware raid is done on the interface card and comes up the same way. Neither can know which of the members of the mirror are available at first boot; otherwise, there would be a single point of failure during boot, and the whole purpose of a RAID 1 mirror would be lost.
The bootstrap starts on the mirror primary, then, as the driver is brought online and before any writes are done, the driver collects the members of the RAID 1 mirror set and forms the mirror. If the mirror primary isn't available, then the mirror secondary is used (which has an exact copy except for stuff indicating that it is the secondary). All this happens normally during boot, as if from a single non-RAID drive, until the cutover is made to RAID early in the driver intialization.
That's why booting from a RAID 0 (stripe) is so hard - all of the data is not present on a single drive. It can be done, but it is hard and requires special care during the boot.
You really do want to make the upgrade to AppleRAID 2 before spending time on the update, though. There are details in this article on afp548.com:
http://www.afp548.com/article.php?story=AppleRAID2-in-Depth
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

Left side of XServe Raid disappeared. Please help

Hello,
During the cleanup of a bunch of data on right side of my XServe Raid (two raid 5's with spare, one on the left side, one on the right side), the server became very unresponsive (Windows 2k server), to the point where it wouldn't even shut down. I reset the box but when it came back up the left side of the XServe was gone (showed up as a missing drive in disk manager).
RAID Admin shows that there is no raid on the left side and shows all drives as spares. I've just completed copying all the data off of the still functional right hand side and can now attempt to recover the left side (if that's even possible?). I saw a suggestion that full power offs and restarts (multiple times) has helped another poster. So far I have powered down the XServe Raid 2 or 3 times without the left side raid showing up. I'll be trying a few more times shortly.
I believe there is an option to recover the raid in RAID Admin? My XServe has an older version of firmware that does not support the RAID Admin Utilities. I have been nervous of upgrading the firmware and possibly irreversibly losing the raid if it isn't already irreversibly gone.
Can anyone offer any suggestions?

No luck on the reset, both via Raid Admin and the reset button on the XServe Raid.
A restore of most of the data has completed onto another storage device.
I can see a power spike or something wiping out the config of both arrays, but to have only one side just disappear and with no way to re-read the raid configuration from the drives, I can't trust the XServe RAID anymore and we won't be going back to using it.
I certainly appreciate you taking the time to offer a suggestion Camelot!

Basic Xserve Raid Set Up Help

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