As long as both have the same hardware and firmware revisions, it should work just fine. Occasionally there are issues, but it has never happened to me in dozens of attempts. In my test lab, I swap drives/arrays from one machine to another all the time - on 2650's and 2850's. However, having worked for Dell in server tech support, I know that things happen that are unexpected. It is a sound strategy, but don't put all your eggs in that basket.
Yes, in the situation you described in the original post, moving the drives to another machine should work just fine. 3/Di to 3/Di should not be a problem - migrating to a different controller altogether - 3/Di to 3/DC or 3/Di to 4/Di, etc. will not work, as they are different manufacturers (for example, you could not successfully migrate the VD's from a 2650 to a 2600 for this reason), but as long as it is like to like, there should not be an issue and I'll describe to you what you will see.
When a RAID array is created, the RAID header information is written to the NVRAM of the controller and the drives themselves, so when you take drives and put them in another machine, it will inform you that array information has been found on the drives that is different (mismatch) from what is stored in NVRAM and ask you what you want to do with it. You will accept the current configuration (which is the configuration from the drives), and that is what the controller will use.
Now in order to minimize the chances of something going wrong, you will want the machines to be as identical as possible. No PCI cards or external devices on one that is not on the other - otherwise, the driver information on the drives may not be suitable for the installed devices and can cause multiple problems. Firmware is also important - the RAID controller firmware dictates how it manages the arrays that are configured on it, so as features and fixes are installed through these updates, older firmware may not know how to handle them or recover from their presence. As the system's support of the controller is aided by the BIOS and ESM, you should make sure they are up to date as well. These updates will ensure hardware on both machines are "on the same page" and operate the same way.
Like I said, I have never encountered an issue in doing this myself, but I have had customers whose controllers didn't recognize the new config at all, whose config was recognized and imported, but OS wouldn't load, and one that wouldn't recognize all the drives. In every case (except the last), there was differing firmware versions or differing hardware (different brand add-in NICs in each). The last one was kind of bizarre, as it was not consistently recognizing any drive - even empty, newly configured drives. To recover, all that was needed was to put the drives back into the original machine (once it was repaired). I did have one customer whose configuration was lost even after moving back to the original, but I don't believe he gave us all the information to really know what happened.
So, this is a chance to save some downtime, but please keep a current and validated backup in case something goes wrong or some other problem wipes out your data.
That's interesting that you've tried that successfully. Is that the same thing as what is described in the section titled, "Moving Physical and Virtual Disks from One System to Another" in Dell's RAID documentation set? That's exactly what I want to do - move a PERC 3/Di virtual disk to another system (also a PERC 3/Di). There is very little mention of PERC 3/Di virtual disk migration capabilities.
I wonder if there's additional PERC 3/Di documentation out there that can discuss this process further. I haven't been able to find any.
So here's a million questions for you:
So if migrating a virtual disk from a source PERC 3/Di system to a target PERC 3/Di system is possible - what are the required conditions for the target machine?
Does the RAID controller need to be configured identically?
What issues have you encountered while performing this operation?
When you or your customers experienced issues that prevented a successful migration then what steps did you take to recover?
By hardware and firmware revisions - what specific components are you referring to? You must mean the RAID controller firmware at the very least.
By "older controllers," I assume you mean PERC 3/Di? In this situation that's the only type of RAID controller I'm working with.
A PowerEdge 2650 has 5 drives in the front. I believe the disks you plug into the front are associated with channel 0 and the SCSI IDs map to the following if you are facing the front of the machine:
0 - 2 - 4
x - 1 - 3
where 'x' is a filler for the area that the optical media and floppy consume - there is no SCSI drive there.
So if I was to migrate the disks - disk in position Y in the production machine would have to go to position Y in the backup machine for Y = 0, 1, 2, 3, 4. Assume I'm moving the disks to another PowerEdge 2650.
Do the channels work that way? Let me know if I got that right.
As note, the older controller do not allow drive roaming...
From the manual
"When moving the array disks from one enclosure to another, the SCSI ID for each disk must remain the same."
"When moving the arrays disks from one enclosure to another or when moving an external enclosure from one server to another, the enclosure must be connected to the same channel number on the controller as in the original condition."
Best to manually document the setup, and mark the drives as they are removed.
You got the drive layout right ... make sure you get the drives in the right order on a 2650 when transferring them to another machine, or game over :) The 2650 can be configured with a daughtercard to split the backplane - make sure they both have or both don't have this card.
<ADMIN NOTE: Broken link has been removed from this post by Dell>
theflash1932
9 Legend
•
16.3K Posts
0
January 7th, 2010 07:00
As long as both have the same hardware and firmware revisions, it should work just fine. Occasionally there are issues, but it has never happened to me in dozens of attempts. In my test lab, I swap drives/arrays from one machine to another all the time - on 2650's and 2850's. However, having worked for Dell in server tech support, I know that things happen that are unexpected. It is a sound strategy, but don't put all your eggs in that basket.
theflash1932
9 Legend
•
16.3K Posts
0
January 8th, 2010 09:00
Yes, in the situation you described in the original post, moving the drives to another machine should work just fine. 3/Di to 3/Di should not be a problem - migrating to a different controller altogether - 3/Di to 3/DC or 3/Di to 4/Di, etc. will not work, as they are different manufacturers (for example, you could not successfully migrate the VD's from a 2650 to a 2600 for this reason), but as long as it is like to like, there should not be an issue and I'll describe to you what you will see.
When a RAID array is created, the RAID header information is written to the NVRAM of the controller and the drives themselves, so when you take drives and put them in another machine, it will inform you that array information has been found on the drives that is different (mismatch) from what is stored in NVRAM and ask you what you want to do with it. You will accept the current configuration (which is the configuration from the drives), and that is what the controller will use.
Now in order to minimize the chances of something going wrong, you will want the machines to be as identical as possible. No PCI cards or external devices on one that is not on the other - otherwise, the driver information on the drives may not be suitable for the installed devices and can cause multiple problems. Firmware is also important - the RAID controller firmware dictates how it manages the arrays that are configured on it, so as features and fixes are installed through these updates, older firmware may not know how to handle them or recover from their presence. As the system's support of the controller is aided by the BIOS and ESM, you should make sure they are up to date as well. These updates will ensure hardware on both machines are "on the same page" and operate the same way.
Like I said, I have never encountered an issue in doing this myself, but I have had customers whose controllers didn't recognize the new config at all, whose config was recognized and imported, but OS wouldn't load, and one that wouldn't recognize all the drives. In every case (except the last), there was differing firmware versions or differing hardware (different brand add-in NICs in each). The last one was kind of bizarre, as it was not consistently recognizing any drive - even empty, newly configured drives. To recover, all that was needed was to put the drives back into the original machine (once it was repaired). I did have one customer whose configuration was lost even after moving back to the original, but I don't believe he gave us all the information to really know what happened.
So, this is a chance to save some downtime, but please keep a current and validated backup in case something goes wrong or some other problem wipes out your data.
WalkerTechnolog
16 Posts
0
January 8th, 2010 09:00
That's interesting that you've tried that successfully. Is that the same thing as what is described in the section titled, "Moving Physical and Virtual Disks from One System to Another" in Dell's RAID documentation set? That's exactly what I want to do - move a PERC 3/Di virtual disk to another system (also a PERC 3/Di). There is very little mention of PERC 3/Di virtual disk migration capabilities.
I wonder if there's additional PERC 3/Di documentation out there that can discuss this process further. I haven't been able to find any.
So here's a million questions for you:
So if migrating a virtual disk from a source PERC 3/Di system to a target PERC 3/Di system is possible - what are the required conditions for the target machine?
Does the RAID controller need to be configured identically?
What issues have you encountered while performing this operation?
When you or your customers experienced issues that prevented a successful migration then what steps did you take to recover?
By hardware and firmware revisions - what specific components are you referring to? You must mean the RAID controller firmware at the very least.
WalkerTechnolog
16 Posts
0
January 8th, 2010 13:00
By "older controllers," I assume you mean PERC 3/Di? In this situation that's the only type of RAID controller I'm working with.
A PowerEdge 2650 has 5 drives in the front. I believe the disks you plug into the front are associated with channel 0 and the SCSI IDs map to the following if you are facing the front of the machine:
0 - 2 - 4
x - 1 - 3
where 'x' is a filler for the area that the optical media and floppy consume - there is no SCSI drive there.
So if I was to migrate the disks - disk in position Y in the production machine would have to go to position Y in the backup machine for Y = 0, 1, 2, 3, 4. Assume I'm moving the disks to another PowerEdge 2650.
Do the channels work that way? Let me know if I got that right.
pcmeiners
4 Operator
•
1.8K Posts
0
January 8th, 2010 13:00
As note, the older controller do not allow drive roaming...
From the manual
"When moving the array disks from one enclosure to another, the SCSI ID for each disk must remain the same."
"When moving the arrays disks from one enclosure to another or when moving an external enclosure from one server to another, the enclosure must be connected to the same channel number on the controller as in the original condition."
Best to manually document the setup, and mark the drives as they are removed.
theflash1932
9 Legend
•
16.3K Posts
0
January 8th, 2010 15:00
You got the drive layout right ... make sure you get the drives in the right order on a 2650 when transferring them to another machine, or game over :) The 2650 can be configured with a daughtercard to split the backplane - make sure they both have or both don't have this card.
<ADMIN NOTE: Broken link has been removed from this post by Dell>