Need larger root disk, step-by-step instructions

[R Swenson]

I'm trying to upgrade to Tru64 version 5.1a from 5.1 and my root domain has only about 8MB free space. I have cleaned out all I can and need to replace the current disk with a larger one, then redefine the root partition to 2GB.

I am a relative newbie with a disk on my desk and a StorageWorks cabinet. Where do I go from here (and please be specific)?

[Ivan Ferreira]

This could be a problem, because you cannot use addvol for the root domain to increase the space. Your options are:

- Delete more files
- Backup, destroy, restore your root domain.

How large is your root file system? Can you post the output of df -k? Normally 100-250 MB should be used in the root domain.

What is the exact model of your storage box?

[R Swenson]

Filesystem 1024-blocks Used Available Capacity Mounted on
root_domain#root 131720 115827 8824 93% /
/proc 0 0 0 100% /proc
usr_domain#usr 2097144 1231888 662544 66% /usr

The root domain is 131MB total, it was set up back in 1998 and looks like it was set up according to system recommendations back then (Version 4.0D).

If I need to backup root, do I also need to backup /adm and /var as well? Do I need a swap space on the root disk? I believe the current disk is a 4.3GB disk, how much space should be partitioned for each?

The storage box in question is a DS-SWXES-BA StorageWorks 10000 Enterprise Storage Array. The CPU is an AlphaServer 1200 with 1 - 4.3GB disk mounted within its cabinet (I'm guessing this is the disk in question). There are 6 addidional open slots in the AlphaServer cabinet. Thanks!

[R Swenson]

Also, HP Support told me that I should set up the root partition somewhere between "500MB and 1GB". Why the discrepancy with your recommendation?

[Ivan Ferreira · Accepted solution]

I mean the used space, I use to do my root file system 700-1GB large.

If you want to keep /usr and /var swap on the same disk, you should backup it also, otherwise only root.

I don't know about your storage, but the basic procedure will be:

Create a new LUN.
Present it to the host.
Partition the disk (diskconfig)
Backup the data with vdump.
vdump -0uf /dev/tape/tape0c /
Boot from the installation cd
Create the new root domain
mkfdmn -r /dev/disk/dskXa root_domain
mkfset root_domain root
mount root_domain#root /mnt
/sbin/dn_setup -install_tape
vrestore -xf /dev/tape/tape0 -D /mnt
Fix the link in /mnt/etc/fdmns/root_domain

See:

Recovering Data from a Corrupted root Domain in AdvFS Administration manual.

[Mark Poeschl_2]

If you're contemplating a full backup/restore of / (root) with a disk reorganization chances are you'll need to do the same with /usr and /var. They're often put on the same device - in your case the single 4.3 GB drive in the server's enclosure. If I were you I'd consider either getting more/bigger drives in the local enclosure and restoring onto those or just abandoning local storage altogether and put everything on the ESA10000.

HP's recommendation of 500-1000 MB for root is more than likely due to the fact that gigabytes are cheap these days and is 'just to be on the safe side.' It may also be related to the fact that if you ever move to a clustered configuration you need as much as 50% free space in the root file system to allow for rolling upgrades.

[R Swenson]

Thanks to you both for your help. I have a much better idea how to go about this!

[R Swenson]

One last question (for now anyway!): Can I partition the new disk via a GUI interface? I saw something similar to ths once but I can't remember how to get back into it. Thanks!

[Ivan Ferreira]

Yes, you can partition the disk with the GUI (diskconfig).

If you have any errors using the GUI, use disklabel -z and disklabel -rw to zero the disk label and rewrite a new default label.

[Mulgund]

One alternative procedure to what Ivan suggested could be ...

Connect a simple tape drive to the system.
take a btcreate of /(root), /var, /usr on to a tape. See man btcreate and sysadmin guide for details.

Now create a new LUN.

Present it to the host.

Just btextract the above created root configuration on to this newly created LUN.
See man btextract and sysadin guide for the same.

At the end of above procedure you would have migrated your root, /var, /usr filesets to the new(bigger) LUN.

Hope this helps.

Regards,
Srinivas