On 07/22/2010 06:30 PM, Scully, William P wrote: > Where or how is a disk address mapped to /dev/dasdx (where "x" is a, b, > c)? I ask because at install time I am -certain- that I instructed the > partitioner to make the 200 disk to be /dev/dasda1, the 201 to be > /dev/dasdb1, and 202 to be /dev/dasdc1. (I have a screen-shot of the > VNC windows, but won't include it here.) > > After installation completes I see: > > linux024:~ # cat /proc/dasd/devices > 0.0.0201(ECKD) at ( 94: 0) is dasda : active at blocksize: > 4096, 600840 blocks, 2347 MB > 0.0.0202(ECKD) at ( 94: 4) is dasdb : active at blocksize: > 4096, 600840 blocks, 2347 MB > 0.0.0200(FBA ) at ( 94: 8) is dasdc : active at blocksize: > 512, 409600 blocks, 200 MB > > How can I change the DASDA, B, and C settings around? Or am I missing a > step in the expert partitioning, during set-up? > > > This is on SLES 11.
IIRC, SLES 11 activates DASDs during installation in the order provided manually by the user through the YaST UI or in an autoyast configuration file. Only during installation, it arranges for /dev/dasdX device names to have a predictable order and thus being able to use those kernel device names for partitioning during installation. In the installed system, DASDs (or zFCP LUNs or network devices) are activated by udev rules /etc/udev/rules.d/51-<devicetype>-<devicebusid>.rules. Since udev executes rules in parallel, the ordering of all those 51-rules cannot be predetermined. Therefore, you should use persistent device names to reference, e.g. DASDs, instead of their kernel device names /dev/dasdX. Symlinks such as /dev/disk/by-path/ccw-<devicebusid> work well to reference DASDs by their devno. YaST can be told to use this as identifier for partitions in /etc/fstab and IIRC by-path is the default in SLES 11. Steffen Linux on System z Development IBM Deutschland Research & Development GmbH Vorsitzender des Aufsichtsrats: Martin Jetter Geschäftsführung: Dirk Wittkopp Sitz der Gesellschaft: Böblingen Registergericht: Amtsgericht Stuttgart, HRB 243294 ---------------------------------------------------------------------- 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/
