Connecting an external Surestore Unit

[Jenifer Martins]

I currently have one 9000 D-class server with 2 external Surestore Storage Units attached and a DLT autoloader. I have another 9000 D-class server that I just rebuilt. I would like to remove one of the Surestore Units and attach it to the one I just rebuild. Is it possible to do this without losing the data on it? Do I have to remove the data first prior to installation? I know that creating lg & vg deletes what is on the drives.. but is there away around it? Thanks

[MANOJ SRIVASTAVA]

Hi Jennifer


If you are talking of losing data on disks then it is possible in case you assign a clshing id to the Surestore , otherwise it is very simple.

1.Remove it physically and check for the SCSI id on the drive , disks attached to the contorller where you will attach the surestore.
2. Connect and bring up the box , you will be able to see the drive.

All the best.

Manoj Srivastava

[Stefan Farrelly]

All you need to do is vgexport the volume groups on the external surestore drives, unplug them and plug into the other HP server, then do an ioscan and insf -e to create the new disk device files, then you can use the vgimport command to load the data onto your new servers without losing anything!

[Patrick Wallek · Accepted solution]

Prior to removing the unit from its current box do a:

vgexport -m /var/tmp/vg??.map -p -s -v vg??

Copy the vg??.map file to the surestore's new home.

Move the surestore unit to the other box, power everything up and make sure that all the luns on the surestore are seen by the new box.

Now on the new box do a:

mkdir /dev/vg??
mknod /dev/vg??/group c 64 0x0?0000
vgimport -m /var/tmp/vg??.map -s -v vg??
vgchange -a y /dev/vg??

You should now be able to mount the file systems and see the data from your surestore unit.

I ABSOLUTELY DO recommend that you do a backup before you do anything JUST IN CASE!!!

[Jenifer Martins]

Patrick,
prior to removing the unit, do I umount it at all. If so, do I umount it after the vgexport?
The unit is /dev/vg02/lvol1. When I do vgexport, I write it like this:
vgexport -m /var/tmp/vg02.map -p -s -v vg02
Right? Do I need to put in there the lvol1 or does the lvol1 not needed?

Also, for mknod
mknod /dev/vg/??group c 64 0x0?0000... major,minor numbers...where did you get those. Do I get them from the unit prior to detaching.
Please advise. thanks

[Jenifer Martins]

One more thing... since /dev/vg02 consists of 4-18.2Gig hard-drives... which of the "minor/major" numbers do I use?

[Jenifer Martins]

I just did an ll on the /dev/vg02 directory. I saw group, lvol1, and 2lvol1. For the mknod, I assume I am using the minor/major for "Group"
so it looks like:
mknod /dev/vg02/group c 64 0x020000

[Patrick Wallek]

Jenifer,

You can do the vgexport at any time. the '-p' option stands for preview, but it will build the map file for you and that is really all you need for this operation. You don't have to worry about specifying the lvol with vgexport. It will export the entire volume group.

Prior to removing the unit, you should unmount the LVs, and deactivate the VG (vgchange -a n vg02). If you have any entries for these LVs in /etc/fstab, make sure that you remove them.

When importing into the new machine:

Prior to creating the group file with the mknod command, do an 'll /dev/vg*/group' and make sure that no other group file has a 0x020000 minor number.

Your mknod command in your last response is exactly correct.

I hope this helps you!

[Bill Hassell]

An alternative to using the vgimport comand on the new server is to use SAM (did I say that?) Actually, SAM's Import features work on old 9.04 disks all the way through to current systems.

The SAM interface finds all unassigned disks and connects all of them into volume groups. All you need to provide is the name of the volume (like vg02) and unless you have non-standard lvol names, that's it. SAM will create the VG directory and unique group file plus create the correct lvol names. You will have to manually provide alternate links (a second controller channel) if they exist.

If the lvols are non-standard, use the mapfile(s) created on the source system. SAM has a line to specify the name of the mapfile. Note that mapfiles are simple ASCII files that can be created by hand if necessary (except for the -s option which adds the serial number to the mapfile).