changing disk for rootvg?

[bonsky]

AIXers,

i am changing my rootvg disk from 4gb to 18.2gb, then i want to mirror after to another 18.2gb then, retain some of the filesystems in the previous disk of rootvg instead. So that i will erase these filesystems in my new disk. NOw question is, what is the fastest way to do it, aside from using backup restore?
Is it possible fo rme to use alt install in this scenario? would there be an affect to my no. of PPs? of no. of disk size? HOw would i restore my previous rootvg and changing it to another name but still all the filesystem are intact.??
thanks a lot in advance

 

[vickersdc]

Do you want to keep the current size of PP's...? If so, you could extend the max number of PP's in the rotvg and extend it to include the new disk - then migratepv.

 

[ElgisRamon]

I think your best bet is an [tt]alt_rootvg_install -C[/tt] to clone onto your new disk, using the [tt]-i[/tt] option to give it a new [tt]image.data[/tt] file.
I hope it works...
Unix was made by and for smart people.

 

[Guest_imported]

aixpert/s,

i have the same concern, but somewhat smaller HDs. i have 2 of 2.1GB HDs and planning to install all FSs to a one - 9.1GB HD.

i want exactly the same setup and configuration.

can somebody enlighten me on this?

 

[bi]

I think you can do it all by mirroring. I have done it before when I had to move a preinstalled rootvg from a disk drawer to the internal disks. (the steps I had to take included steps to get the internal disks to be renamed hdisk0 and hdisk1 rather than hdisk14 and hdisk 15, although I probably didn't have to be that particular about it. I won't go into those steps here.)

The OS version I did this on is 4.3.3 and it was patched at the time to ML 5, I believe. the command mirrorvg is for version 4.2.1 or higher.

If doing a mirrorvg from two smaller disks to a larger disk doesn't work (you'd have to check the man pages for the correct syntax -- maybe mirrorvg rootvg hdisk<new disk number>?), you can accomplish the same thing by using the mklvcopy command. If you do use the mirrorvg command, you will have to also run the bosboot -a command and change your bootlist with the bootlist command.

To make it really simple, use smit.

First, of course, bring the new disk into rootvg.

The smit path to mirror LVs is:

System Storage Management/ Logical Volume Manager / set Characteristics of a Logical Volume / Add a Copy to a Logical Volume. The Add Copies to a Logical Volume screen is fairly easy to figure out.

Be sure to mirror a-l-l of the logical volumes, especially hd5. After you mirror hd5, you will have to run bosboot -a so the system knows where the additional boot LV is. you will also have to change your bootlist (both for normal and service mode) so the system know about the new disk that is bootable.

Once you get all of the logical volumes on the new, larger disk, test it by changing the bootlist for normal and put the new disk first. Boot the system and watch it come up and make sure it uses the new disk, rather than the older disk.

After you are sure you can boot on the new disk, you can break the mirrors (also using smit if you want). Again, be sure to run bosboot -a so the system knows the old BLV is gone. And, of course, change your bootlists so the old disk isn't listed.

Then, if you want to mirror from the new, larger disk to another disk the same size, just bring the second disk into rootvg and run a mirrorvg rootvg, or go through the LV by LV routine as above.

And finally, check to make sure quorum checking is off for rootvg. If you lose one of the disks of a 2 disk mirrored rootvg and quorum isn't turned off, losing one of the disks will bring the hole system down. To turn off quorum checking, use the smit path System Storage Management / Logical Volume Manger/ Set Characteristics of a Volume Group / Change a Volume Group.

 

[ElgisRamon]

The problem with mirroring is it'll keep the same PP size, but with alt_install you can give a new image.data file with diferent definitions.
I hope it works...
Unix was made by and for smart people.

 

[bi]

Yes, you are right. And going from a 2 GB to an 9 GB disk isn't possible, I don't think, unless you want to waste a lot of disk space -- again because of limitations on the PP size and the number allowed on a disk. I didn't read the problem closely enough.

Sorry.

 

[Guest_imported]

aixpert/s,

i just want to add something - i successfully replaced a 2.1GB HD by a 9.1GB, same VG name.

previously, i have 2 of 2.1GB but needed to add more system space. two VG names (hdisk0=rootvg & hdisk1=datavg), replaced datavg successfully.

the only problem i got afterwards was, i can't figure out how come i'm missing the system definition of &quot;hdisk1&quot;, instead i have this &quot;hdisk2&quot;. actual, system-wise - i got two HDs installed.

when i tried the command &quot;lspv&quot;, it only gives me the:

hdisk0
hdisk2

no &quot;hdisk1&quot;

did i missed something? right now, the system's working great - but i want to know what i missed out.

 

[jpmsh]

RE: And going from a 2 GB to an 9 GB disk isn't possible
Since AIX 433 there is a
chvg -t <factor> rootvg
allowing more than 10xy PPs per Disk!
So probabely &quot;chvg -t 3 rootvg&quot; and mirroring will do your job
(I did it several times)

 

[bonsky]

AIXers,
Thanks a lot for your responses,
I tried to use ALT INSTALL but with the same 18.2 GB disks to migrate my rootvg, and it works perfectly and quite fast i guess.But, haven't tried to migrate 4.2 Gb to 18.2gb yet,
The Current 4.2 Gb has 8mb per PP size. So im sure i dont want to hold this size with my 18.2Gb HD. Im using AIX4.3.3 with RML level 01: i don't want to install yet the latest RML though i know the latest is 06 now. I don't want to touch on the system yet co'z i'm afraid that something might get wrong to the applications once i install the latest RML,, you AIX sometimes..heh3
But with your expertise and experience in these, Do you recommend me to update first the RML to latest before doing the migration or rather stay as is, unless i find something wrong with my migration then i install the RML 06??
And also,just wondering guys, what could possibly happend if i use alt_install with 4.2Gb with 18.2Gb?would it carry the same no. of PPs? or would it automatically adjust its PP size to fit the 18GB? What is the signifance of haviong new image.data here?
Thanks a lot

 

[bi]

To answer your question about the maintenance level: The current one is 9. I would recommend applying a higher maintenance level than the one you have. There were some problems with level 8 that were probably fixed in 9. But you probably are nervous about putting the ver latest one on. Try applying level 7.

You can tell smit to just apply the patches, not commit them. Just be sure to select No to the Commit software updates? question and YES to the Save replaced files? directory under the commit question.

I also recommend making sure you have a current mksysb tape before installing the patches -- just in case. Make another one on another tape after you apply the patches.