Optional:

• Backup you data if not scheduled

# bkconsdata -r ftp -h [ftp host] -u [user] -d [directory]

• Cleanup temporary datas and reboot

# chsvcevent -o closeall
# chhmcfs -o f -d 0
# hmcshutdown -t now -r

If you want to upgrade an HMC with recovery CD from command line, first download the netinstall packages from FTP site

• First download, and put on an ftp server, the latest version of the following files: initrd.gz, bzImage, disk1.img, disk2.img, and disk3.img and also checksums

On the IBM Web site: https://public.dhe.ibm.com/software/server/hmc/network/

• Take a backup on disk of the datas needed for upgrade:

hscroot@HMC:~> saveupgdata -r disk

• Download on the HMC the file from ftp server, and reboot with upgrade you can use SFTP, FTP or NFS:

hscroot@HMC:~> getupgfiles -r sftp -h 10.10.10.10 -u ftpuser --passwd xxxxxx -d /software/hmc 
hscroot@HMC:~> chhmc -c altdiskboot -s enable --mode upgrade
hscroot@HMC:~> hmcshutdown -r -t now

• After about 30 min, the HMC is back again, and you can apply the latest patches (from cental fixes), directly from Web interface.

• Download the latest Recovery DVD from IBM central fixes www.ibm.com/support/fixcentral

• Before Stopping HMC, go into HMC Management –> Save Upgrade Data –> On disk

• Stop the HMC, and restart with DVD

• You 'll answer some questions, and at the end the HMC will restart on the right level

The easiest way is to download all latest and recommended fixes, as iso images, and put it into an empty directory on an ftp server.

Using command line on the HMC:

updhmc -t sftp -h <ftpservername> -f </home/updates/corrrective_service.iso> -u <ftpusername> --passwd <ftppassword> -c -r

Or on the HMC web interface, go into Update, and click on the HMC Update button.
–> select Remote server
–> put the location on the ftp server, it will discover all available iso files
–> select one at time and start the update, first a SP if one available
–> you have to reboot between all updates

If on package failed to installed, it's maybe no more needed.

https://www.volubis.fr/news/liens/courshtm/HMC_v9U.htm