James, Almost completely correct. In fact, where your root file system is located has nothing to do with what device number you IPL/boot from. It just so happens that the volume containing the root file system has been where things default to, because that is where the /boot directory is most often located.
I've done things like create a /usr/boot, or a /var/boot directory, copied the contents of /boot into it, made whatever changes I wanted in terms of kernel, parmfile, etc., and ran zipl pointing to those files. Then, instead of IPLing from my usual device number, I boot from the device number that particular file system lives on, and I have a fallback to my "production IPL volume" if things don't work out right. So, it's not that you were wrong, exactly, but knowing this might give you some flexibility in your DASD re-arrangement. Mark Post -----Original Message----- From: Linux on 390 Port [mailto:[EMAIL PROTECTED] On Behalf Of James Melin Sent: Monday, March 22, 2004 10:19 AM To: [EMAIL PROTECTED] Subject: Relationship of parmfile device order to filesystem 'letter' (dasda, dasdb etc) If I am understanding this correctly...... Parmfile device order determines what devices is what file system Parmfile: dasd=a23c,b213,b214,b215,b216,a23d root=/dev/dasdb1 noinitrd cat /proc/dasd/devices seems to confirm the device/filesystem relationship. Now /etc/fstab has this: /dev/dasda1 swap swap defaults 0 0 /dev/dasdb1 / ext2 defaults 1 1 /dev/dasdc1 /var ext2 defaults 1 2 /dev/dasdd1 /opt ext2 defaults 1 2 /dev/dasde1 /usr ext2 defaults 1 2 /dev/dasdf1 /tmp ext2 defaults 1 2 So if I have this correct, the device order in tha parmfile controls what filesystem is assigned to what physical device and /etc/fstab determines where they are mounted, and that specifying what file system root is on in the parmfile is so that the system can boot, and that the /dev/fstab entry for '/' is not redundant but is used when root is mounted r/w after boot? If these assumptions are correct, I think I can proceed with re-carving my dasd. ---------------------------------------------------------------------- For LINUX-390 subscribe / signoff / archive access instructions, send email to [EMAIL PROTECTED] with the message: INFO LINUX-390 or visit http://www.marist.edu/htbin/wlvindex?LINUX-390 ---------------------------------------------------------------------- For LINUX-390 subscribe / signoff / archive access instructions, send email to [EMAIL PROTECTED] with the message: INFO LINUX-390 or visit http://www.marist.edu/htbin/wlvindex?LINUX-390
