Solaris 9 mirrored disk replacement
Not sure if this is the correct forum....but here goes
Aside from DiskSuite, how can I replace a mirrored disk in a cPCI box without bringing down the system? The disk is hot swappable however, I realize there needs to be no activity on the controller for that bus in order to pull the disk out. I don't want to have to bring down the system in order to replace the disk.
Is there a Sun procedure or instructions for creating a script to accomplish this? I ve tried googling it, came up empty. Any suggestions would help.
Thanks,
Mistervelasco
# 1
Im affraid we need to know more detail about this, I.E. Server type, what cards you have in it, what you have connected to it, etc.
# 2
This is unit in a test environment. Its a GNP/Pinnacle Node3u cPCI box using SCSI wide disks, SNAC card, CP2140 cpu, CP2140 rtm. This unit is in a raid0 configuration. We are able to bring the unit down by editing the md.conf to clear the disks s/n, bring the system down (init0), replace with a new drive, boot -r, and reload the mirroring. However, we don't want to bring the system down.
# 3
There is a very great difference in the actual definitions of HOT-SWAP versus HOT-PLUG, when it comes to disk drives.
I'm sure <i>Stumoor</i> can eventually give some guidance, once this current configuration is understood.
<u>HOT-SWAP</u> would mean you could just walk up to the system, eject the questionable drive, then snap in the new disk, and then walk away.
Somehow, magically, the OS, the disk controllers, and the Volume Management suite recognize the change and puts the proper filesystems and data to the new drive.
<u>HOT-PLUG</u> would mean that the system's administrator would need to quiescent all filesystems on the questionable disk, confirm it's then unmounted, and then the physical replacement can occur.
Once that is done, the SysAdmin can re-engage whatever is necessary to put the new disk into production.
The only thing common to both scenarios is that power does not need to be turned off.
<i>Stumoor</i>, is that your understanding, as well?
# 4
Basically yes, as rukbat said those are effectively the definitions. I have never come across a Pinnacle Node3u cPCI box before, I assume we are looking at this:
<a href="http://www.pinnacle.com/products2/compactpci/3U/" target="_blank">http://www.pinnacle.com/products2/compactpci/3U/</a>
Whatever array the disk is in, if you are sure it is hot swappable then Solaris would deal with it, you might have to run something like devfsadm to force the OS to check for disks. The only other thing I would be careful of is the disk management.
How I would go about doing this, is as follows:
1. Break any mirrors, etc that you have on this disk.
2. If it is Disksuite, make sure you remove and metadbs from the problem disk.
3. After which you can swap the disk.
4. Run devfsadm and check format, etc so make sure I can see the disk.
5. Redo any partitioning, metadbs and recreate the mirrors.
That is how I would do it. Let us know how you decide to do t and how you get on.
# 5
Sounds simple engough. The problem I see there is our necessity of editing the md.conf file. The way I understand, the md.conf file holds the s/n of the disk in use. In order for the system to detect a new drive, I would I have to edit this file, clearing the current s/n's bring the system down and the reboot so the system can rewrite the disk info and verify the disk is seen by system, then recreate mirroring. (We have seen disk read errors while trying to recreate the mirroring by not editing the md.conf file.) I would think there should be some other way of getting the system to recognize the new disk, then by having to reboot. From what our engineers tell us, it is possible, but up to Solaris . The disks support 'basic hardware Hot-swap'. This tells me the disks can be hot- swapped, but Solaris 9 needs to hold all activity on this controller to allow the disk to be swapped. Follow?
So, someone mentioned Disksuite / Volume Manager would allow this but would require time/resource to put together. Any suggestions?
Thanks
