Converting HFS to VxFS on 10.20

[Michael Streifel]

I've run into an Oracle database bug on HP-UX 10.20 were performance on HFS is very poor. I need to convert 6 mirrored logical volumes from HFS to VxFS. What is the best way to do this?

[Sanjay_6 · Accepted solution]

Hi Michael,

No easy way to convert from hfs to vxfs. You have to take complete data backup and then remove the hfs filesystems, create new vxfs filesystems, and then restore the data.

http://us-support.external.hp.com/cki/bin/doc.pl/sid=4e204bd30776057de2/screen=ckiDisplayDocument?docId=200000048580810

Hope this helps.

Regds

[Bernie Vande Griend]

There are no conversion tools. You'll have to create new logical volumes as type vxfs and restore the data to them (unfortunately).

Here is a document explaining that in a bit more detail:
http://us-support.external.hp.com/cki/bin/doc.pl/sid=2e827d17004305191d/screen=ckiDisplayDocument?docId=200000024625487

[Sanjay_6]

Hi Michael,

Here are a few more helpful readings.

http://us-support.external.hp.com/cki/bin/doc.pl/sid=4e204bd30776057de2/screen=ckiDisplayDocument?docId=200000024625487

http://us-support.external.hp.com/cki/bin/doc.pl/sid=4e204bd30776057de2/screen=ckiDisplayDocument?docId=200000007950942

http://us-support.external.hp.com/cki/bin/doc.pl/sid=4e204bd30776057de2/screen=ckiDisplayDocument?docId=200000050014306

http://us-support.external.hp.com/cki/bin/doc.pl/sid=4e204bd30776057de2/screen=ckiDisplayDocument?docId=400000000088267

Hope this helps.

Regds

[Patrick Wallek]

There is no way to "convert" an HFS LV to VxFS. What you could do, since you say your stuff is mirrored is:

1) lvreduce -m 0 ..... So that you are no longer mirrored.
2) Create new VG and LVs on the disks that were your mirrors, creating your LVs as VxFS. Mount them with different dir name (append a .new to the dir. data.new for example)
3) Copy the data from the HFS to the VxFS LVs.
4) Unmount the HFS and VxFS LVs then remount the VxFS as the correct directory name.
5) vgextend the disks that were the HFS LVs into your new VG and then do an 'lvextend -m 1 ...' to recreate your mirrors.

The DB does have to be down when you are doing this. I would still recommend that you make a backup of your data, but if you do it this way, you shouldn't have to restore from tape, which is slow.

If you don't have it, I would also look at acquiring the Online/JFS product and use the 'mincache=direct,convosync=direct,nodatainlog,delaylog' options when mounting the VxFS LVs. These options usually increase performance even more.

[A. Clay Stephenson]

Hi:

This should work. I assume that your mirrors are on separate physical disks.

Plan A) Fast but several steps

1) Backup
2) For each logical volume, do an lvreduce -m 0 /dev/vg0x/lvolx /dev/dsk/cXtYdZ making sure that you specify the same pv_path on each operation. We want to leave all the lvols on the original disk(s) and remove all the mirrors on the remaining disks.
3) Reduce the volume group, removing the mirror
pv_paths; vgreduce /dev/vg0x /dev/dsk/cXtYdZ; repeat as needed for the number of mirror pv_paths
4) For each mirror device do a pvcreate
pvcreate -f /dev/rdsk/cXtYdZ
5) Now create a new volume group using vgcreate after making the new /dev/vgxx directory and group file. Add the mirror disks to this new VG.
6) Create the new lvols and filesystems
7) mount the new filesystems using temporary mountpoints
8) Copy the old filesystems to the new using your weapon of choice, cpio -p, cp -R, ...
9) Unmount the old filesystems, unmount the new filesystems, remount the new filesystems with the old names
10) vgexport the old volume group
11) pvcreate the remaining old volume group disks.
12) vgextend the new volume group using the remaining old volume group disks
13) lvextend -m 1 the new LVOLS to re-establich mirroring.

Plan B): Slower but easier
1) backup
2) newfs on each LVOL
3) restore

Regards, Clay

[Roger Baptiste]

Hi,

Make sure you have the
JFS product installed on
the box.
#swlist |grep -i jfs

Also make sure you have
the JFS product enabled
in the kernel

#grep vx /stand/system
-> should return vxbase

Plan for a downtime , time
depending on the size of the
database,
Shutdown oracle. Take backup.
Umount all filesystem related to oracle.

Do #newfs -F vxfs -b /dev/vgxx/lvname
{on all the lv's related
to the db filesystems).

#remount filesystems

#Restore the DB.

HTH
raj

[Andre Da Silva Dias]

Hi,

If you upgrade your 10.20 to 11.0 or 11i you have the new JFS 3.3 which allows you to convert hfs to jfs using vxfsconvert.

More info on:
http://devresource.hp.com/STK/impacts/i735.html

Regards,
Andr??

[Michael Streifel]

I have enough space on the other disks so that I can backup to them instead of tape. Thank you for the great information.

[harry d brown jr]

Best way?

backup system. blowaway HFS. Load the latest patches. create the filesystems, restore data.


live free or die
harry