Hi all, I was trying to use a loop device(s) for LVM. In the pvcreate man-page it is said that a PV can also be a loopback file. That also seem to work correct. But when I try to create a VG on that I get: [root@arthur /tmp]# vgcreate tmpvg /dev/loop0 vgcreate -- no valid physical volumes in command line Pvdisplay gives: [root@arthur lib]# pvdisplay /dev/loop0 pvdisplay -- ERROR "pv_read(): pv_create_name_from_kdev_t" no VALID physical volume "/dev/loop0" 'pvdisplay -d /dev/loop0' gives in the end: ... <22> pv_create_name_from_kdev_t -- CALLED with 7:0 <333> lvm_check_dev -- CALLED <4444> lvm_check_partitioned_dev -- CALLED <55555> lvm_get_device_type called <55555> lvm_get_device_type leaving with 3 <4444> lvm_check_partitioned_dev -- LEAVING with ret: TRUE <333> lvm_check_dev -- LEAVING with ret: 1 <333> lvm_dir_cache -- CALLED <333> lvm_dir_cache -- LEAVING with ret: 22 <22> pv_create_name_from_kdev_t -- LEAVING with dev_name: (null) <1> pv_read -- LEAVING with ret: -278 <1> lvm_error -- CALLED with: -278 <1> lvm_error -- LEAVING with: "pv_read(): pv_create_name_from_kdev_t" pvdisplay -- ERROR "pv_read(): pv_create_name_from_kdev_t" no VALID physical volume "/dev/loop0" So it looks like that pv_create_name_from_kdev_t has the correct input for loop0, but lvm_dir_cache does not know anything about loop devices. (When I use disc partion for a PV, pv_create_name_from_kdev_t leaves with a correct device file name). BTW, I'm using RH 7.2 and 2.4.16 kernel. I tried this on the two different machines with the same results. Has loop devices ever worked and has anybody actually used them? For me being uninitiated it is a bit hard to understand why would lvm have to guess (and fail) a device file name from its major and minor numbers in the first place when I just give that in the command line... -Mika P.S. Thank you for the good work otherwise -- Mika Länsirinne, System Manager / Research Engineer, M.Sc. (E.E.) Helsinki University of Technology Electronic Circuit Design Laboratory P.O. Box 3000 Email: mla@ecdl.hut.fi FIN-02015 HUT Tel: +358 9 451 2277 Finland Fax: +358 9 451 2269
