Originally posted by: SystemAdmin

I need to convert some non rootvg filesystems from JFS to JFS2.

The current plan involves assigning a new and temporary LUN to the server and then,
Creating a VG, LV and filesystem on that LUN.
Stopping all activity on the server.
Backing up/copying the filesystems from the source to the temp LUN
Deleting everything in the source VGs, keeping the VGs as is.
Restoring everything from the backup.

What would be the most efficient method of backing up this data, backup or something else?

AIX 5.3 ML02

Thanks in advance
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Originally posted by: orphy

Since you don't have space problem, why do you need to actually do
a backup/restore? You could if you really want to be careful and for
that, try the backup command or tar though you might want the GNU tar.

Here's one way to do it but you definitely should try it out first
before doing the actual move.

1. rename the changing jfs

umount /orphy
chlv -n tmporphylv orphylv
chfs -m /tmporphy /orphy
mount /tmporphy

1. recreate in jfs2 and move from jfs to jfs2

mklv -t jfs2 -y orphylv...
crfs -v jfs2 -m /orphy -d orphylv...
mount /orphy
mv /tmporphy/* /orphy/ # or maybe use "cp -Rph" instead

Test things out here to make sure things still work!

1. clean up when things work

umount /tmporphy
rmfs /tmporphy
rmdir /tmporphy
reducevg/rmdev/etc/etc/etc
Orphy
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Originally posted by: SystemAdmin

When moving data around disks, I like to add a new disk, vg and filesystem, then rsync the data, then unmount the source and mount the copy...

current data
/data (vg1)- (jfs)

create a new vg/lv/fs
/new/data (vg01) -(jfs2)

rsync the /data -> /new/data

unmount /data
unmount /new/data

chfs -m /old/data /data
chfs -m /data /new/data

mount /data
mount /old/data

you should now have the data on the new fs with the /old/data as a reference/backup. This means that if anything is missing or incorrect (permissions/ownership) you can check the original data.

After it's been confirmed to be ok, you can unmount the old fs and reclaim the disk.

I have done this on several data moves with no problems.

Cheers...Steve
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Originally posted by: nagger

Add the new LUN, VG and JFS2 filesystem
Mount the filesystem on /new and assuming the currently is called /old below
Then cd /old
tar cf - . | (cd /new; tar xf - )
The umount both
Change /etc/filesystems so the /new now mounts at /old
Mount /old (actually the new one)
Remove the old filesystem
There seems to be no point in moving the data back to the original disk/LUN !!

Of course you should have a backup too - for safety and just as a good practice.
I
Hope this helps, N
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Originally posted by: SystemAdmin

These steps are nice, only if you have a small system.
What would happen if you have a system with over 5TB of JFS data, that needs to be converted to JFS2? Would the best way still be to get temporary disks? I don't think thats feasable.


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Originally posted by: orphy

Actually, to me, the "best way" really depends on the site and the resources
available to get the job done. For some, it might be just to back things
up to tape(s) and restore. Most people do back up their files to some kind
of tape storage anyway. And if they do full backups weekly, for example,
it might not be too bad to make this the "best way". The even gives a chance
to test out the restore! Now, for another, it could be grabbing some new LUNs
and moving things over. And for others, it might not even be a big deal just
to leave everything at JFS. What's the reason to convert anyway? Did we hit
a JFS limit? Is there something in JFS2 that we must have? Is this necessary
because of corporate policy?

I would say the site owner has to consider the pros/cons of each method before
figuring out which way to go. I do agree that moving 5TB, for example, is not
something you want to just "go for it" without really considering all the
options. It sure would be nice to be able to run jfstojfs2 and it's all done
for you but the last time I checked, IBM didn't have that available or at least
I wasn't able to find it.
Orphy
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Originally posted by: SystemAdmin

Thanks everyone - I'll be going with the extra lun method and making a note of timings. If I encounter anything useful I'll post.

Thanks for taking the time to answer.
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Originally posted by: esv

I made a copy of /etc/filesystems.

modified /etc/filesystems to indicate rootvg's filesystems were actually jfs2 filesystems.

created a /image.data file and modified the LV and JFS stanzas to indicate that they were JFS2 type and the JFSLOG related to the old JFS filesystems modified it to be a JFS2LOG LV.

created a mksysb and restored the mksysb on an alternate disk/system, both using NIM alt_disk_install and standalone mksysb restore.

So far, I've had success on more than 10 systems and have not had an issue ever, don't call IBM or me if you have problems, the method is not supported.

The attached file contains how /usr would look like in /image.data file before and after.

good luck.
Enrique.
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Originally posted by: iampattoiam

I like the rsync method as you have both copies online at the same time so you can do any checks required. You can run it as 2 rsyncs. The initial rsync can be done online so no interruption. Then do a final rsync with the Application down to get any updates.
If you have disk space limitiations you could do 1 filesystem at a time.
If you want to move Oracle filesystems create your new jfs2 filesystem, then Oracle can move its tables/files online. When Oracle has moved all/most the Oracle files you can shrink the old filesystem (5.3 onwards) to make more room for the next jfs2 filesystem. Do this when I/O is low to prevent contention and impacting performance.

Cheers...Anthony
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