Mark is correct: one automagically created partition. Worse, there is no 'fdasd' or 'fdisk' management of that partition. WORSE STILL, you *must* put the filesystem into the "partition" (such as it is) if you are going to boot from this disk. A filesystem in /dev/dasdx will be clobbered by the first stage of the boot loader, while a filesystem in /dev/dasdx1 is protected by the extra 8K of padding. (12K total)
I checked it again this morning. The bootstrap overwrites the root inode. This is really really sad because partitioning is really really useless otherwise. The moral equivalent in electronics is dropping resistors versus switching power supplies. As the IEEE puts it, "resistance is useless". If you don't need to boot from it, use LDL and use the whole disk. Again, IFF you DON'T need to boot from it (and it's CKD), use /dev/dasdx instead of /dev/dasdx1. In any case, use DIAG wherever possible, which means use LDL wherever possible. God bless whoever in Boeblingen fixed this problem for FBA disks. You can use the pseudo-partition, or not. You can boot from them either way. -- R; <>< Rick Troth Velocity Software http://www.velocitysoftware.com/ On Mon, Jan 3, 2011 at 14:59, Mark Post <[email protected]> wrote: >>>> On 1/3/2011 at 10:59 AM, Samir Reddahi <[email protected]> wrote: >> a couple of questions: >> >> 1) Are there any disadvantages of formatting disks as ldl instead of cdl? > > With LDL, you only get one (automagically created) partition. With z/VM > that's not such a huge problem, since disks can be made any arbitrary size. > In an LPAR environment, it can cause a lot of disk to be wasted if you don't > plan things out. > >> 2) Is it true that /boot directory has to be located on a non-DIAG disk? > > Not to my knowledge. > >> 3) What kind of performance improvement can I expect from a move to DIAG >> dasd >> 4) Any disadvantages of using DIAG instead of ECKD? > > I'll let Barton or Rob answer these two. > > > Mark Post > > ---------------------------------------------------------------------- > 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 more information on Linux on System z, visit > http://wiki.linuxvm.org/ > ---------------------------------------------------------------------- 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 more information on Linux on System z, visit http://wiki.linuxvm.org/
