russell(a)coker.com.au (Russell Coker) writes:
> LVM snapshots are not usably at the moment: for kernel 2.4 they
work with
> a kernel patch only, and for kernel 2.6 they are marked as experimental
> which is confirmed by my experiences (kernel-panics on creation and manual
> cleanup required).
FC2 has kernel 2.6 but doesn't have snapshot support.
FC3 has snapshot support, I've just been using it and it works for me. Can
you file bug reports about any LVM oops you can get with a Fedora
kernel?
Sorry; the FC3 kernel is missing some features so that I have to use the
vanilla 2.6.8.1 kernel + some patches. FWIW, the stacktrace from the
kernel oops is
| Sep 22 04:44:18 delenn kernel: lvcreate: page allocation failure. order:0, mode:0xd0
| Sep 22 04:44:18 delenn kernel: [dump_stack+30/32] dump_stack+0x1e/0x20
| Sep 22 04:44:18 delenn kernel: [<c0105eee>] dump_stack+0x1e/0x20
| Sep 22 04:44:18 delenn kernel: [__alloc_pages+739/784] __alloc_pages+0x2e3/0x310
| Sep 22 04:44:18 delenn kernel: [<c0147723>] __alloc_pages+0x2e3/0x310
| Sep 22 04:44:18 delenn kernel: [alloc_pl+52/96] alloc_pl+0x34/0x60
| Sep 22 04:44:18 delenn kernel: [<c0280914>] alloc_pl+0x34/0x60
| Sep 22 04:44:18 delenn kernel: [client_alloc_pages+37/112]
client_alloc_pages+0x25/0x70
| Sep 22 04:44:18 delenn kernel: [<c0280aa5>] client_alloc_pages+0x25/0x70
| Sep 22 04:44:18 delenn kernel: [kcopyd_client_create+101/192]
kcopyd_client_create+0x65/0xc0
| Sep 22 04:44:18 delenn kernel: [<c02816d5>] kcopyd_client_create+0x65/0xc0
| Sep 22 04:44:18 delenn kernel: [pg0+140642617/1069535232] snapshot_ctr+0x329/0x3c0
[dm_snapshot]
| Sep 22 04:44:18 delenn kernel: [<c8a21939>] snapshot_ctr+0x329/0x3c0
[dm_snapshot]
| Sep 22 04:44:18 delenn udev[2296]: PROGRAM execution of '/sbin/devmap_name 254
5' failed
| Sep 22 04:44:18 delenn udev[2297]: PROGRAM execution of '/sbin/devmap_name 254
6' failed
| Sep 22 04:44:18 delenn kernel: [dm_table_add_target+315/496]
dm_table_add_target+0x13b/0x1f0
| Sep 22 04:44:19 delenn udev[2296]: creating device node '/dev/dm-5'
| Sep 22 04:44:19 delenn udev[2297]: creating device node '/dev/dm-6'
| Sep 22 04:44:19 delenn kernel: [<c027c2db>] dm_table_add_target+0x13b/0x1f0
| Sep 22 04:44:19 delenn udev[2314]: PROGRAM execution of '/sbin/devmap_name 254
7' failed
| Sep 22 04:44:19 delenn udev[2258]: PROGRAM execution of '/sbin/devmap_name 254
4' failed
| Sep 22 04:44:19 delenn kernel: [populate_table+142/240] populate_table+0x8e/0xf0
| Sep 22 04:44:19 delenn udev[2314]: creating device node '/dev/dm-7'
| Sep 22 04:44:19 delenn udev[2258]: creating device node '/dev/dm-4'
| Sep 22 04:44:19 delenn kernel: [<c027edce>] populate_table+0x8e/0xf0
| Sep 22 04:44:19 delenn kernel: [table_load+102/336] table_load+0x66/0x150
| Sep 22 04:44:19 delenn kernel: [<c027ee96>] table_load+0x66/0x150
| Sep 22 04:44:19 delenn kernel: [ctl_ioctl+222/320] ctl_ioctl+0xde/0x140
| Sep 22 04:44:19 delenn kernel: [<c027f70e>] ctl_ioctl+0xde/0x140
| Sep 22 04:44:19 delenn kernel: [sys_ioctl+530/1088] sys_ioctl+0x212/0x440
| Sep 22 04:44:19 delenn kernel: [<c0176cd2>] sys_ioctl+0x212/0x440
| Sep 22 04:44:19 delenn kernel: [syscall_call+7/11] syscall_call+0x7/0xb
| Sep 22 04:44:19 delenn kernel: [<c010510b>] syscall_call+0x7/0xb
| Sep 22 04:44:19 delenn kernel: device-mapper: : Could not create kcopyd client
| Sep 22 04:44:19 delenn kernel:
| Sep 22 04:44:19 delenn kernel: device-mapper: error adding target to table
It happens perhaps once per week (2 snapshots per day) and is not
reproducible.
Enrico