diff options
Diffstat (limited to 'Documentation/uml/UserModeLinux-HOWTO.txt')
-rw-r--r-- | Documentation/uml/UserModeLinux-HOWTO.txt | 66 |
1 files changed, 8 insertions, 58 deletions
diff --git a/Documentation/uml/UserModeLinux-HOWTO.txt b/Documentation/uml/UserModeLinux-HOWTO.txt index 544430e39980..b60590eca18f 100644 --- a/Documentation/uml/UserModeLinux-HOWTO.txt +++ b/Documentation/uml/UserModeLinux-HOWTO.txt | |||
@@ -157,7 +157,7 @@ | |||
157 | 13. What to do when UML doesn't work | 157 | 13. What to do when UML doesn't work |
158 | 158 | ||
159 | 13.1 Strange compilation errors when you build from source | 159 | 13.1 Strange compilation errors when you build from source |
160 | 13.2 UML hangs on boot after mounting devfs | 160 | 13.2 (obsolete) |
161 | 13.3 A variety of panics and hangs with /tmp on a reiserfs filesystem | 161 | 13.3 A variety of panics and hangs with /tmp on a reiserfs filesystem |
162 | 13.4 The compile fails with errors about conflicting types for 'open', 'dup', and 'waitpid' | 162 | 13.4 The compile fails with errors about conflicting types for 'open', 'dup', and 'waitpid' |
163 | 13.5 UML doesn't work when /tmp is an NFS filesystem | 163 | 13.5 UML doesn't work when /tmp is an NFS filesystem |
@@ -379,31 +379,6 @@ | |||
379 | bug fixes and enhancements that have gone into subsequent releases. | 379 | bug fixes and enhancements that have gone into subsequent releases. |
380 | 380 | ||
381 | 381 | ||
382 | If you build your own kernel, and want to boot it from one of the | ||
383 | filesystems distributed from this site, then, in nearly all cases, | ||
384 | devfs must be compiled into the kernel and mounted at boot time. The | ||
385 | exception is the SuSE filesystem. For this, devfs must either not be | ||
386 | in the kernel at all, or "devfs=nomount" must be on the kernel command | ||
387 | line. Any disagreement between the kernel and the filesystem being | ||
388 | booted about whether devfs is being used will result in the boot | ||
389 | getting no further than single-user mode. | ||
390 | |||
391 | |||
392 | If you don't want to use devfs, you can remove the need for it from a | ||
393 | filesystem by copying /dev from someplace, making a bunch of /dev/ubd | ||
394 | devices: | ||
395 | |||
396 | |||
397 | UML# for i in 0 1 2 3 4 5 6 7; do mknod ubd$i b 98 $i; done | ||
398 | |||
399 | |||
400 | |||
401 | |||
402 | and changing /etc/fstab and /etc/inittab to refer to the non-devfs | ||
403 | devices. | ||
404 | |||
405 | |||
406 | |||
407 | 22..22.. CCoommppiilliinngg aanndd iinnssttaalllliinngg kkeerrnneell mmoodduulleess | 382 | 22..22.. CCoommppiilliinngg aanndd iinnssttaalllliinngg kkeerrnneell mmoodduulleess |
408 | 383 | ||
409 | UML modules are built in the same way as the native kernel (with the | 384 | UML modules are built in the same way as the native kernel (with the |
@@ -839,9 +814,7 @@ | |||
839 | +o None - device=none | 814 | +o None - device=none |
840 | 815 | ||
841 | 816 | ||
842 | This causes the device to disappear. If you are using devfs, the | 817 | This causes the device to disappear. |
843 | device will not appear in /dev. If not, then attempts to open it | ||
844 | will return -ENODEV. | ||
845 | 818 | ||
846 | 819 | ||
847 | 820 | ||
@@ -1047,7 +1020,7 @@ | |||
1047 | 1020 | ||
1048 | Note that the IP address you assign to the host end of the tap device | 1021 | Note that the IP address you assign to the host end of the tap device |
1049 | must be different than the IP you assign to the eth device inside UML. | 1022 | must be different than the IP you assign to the eth device inside UML. |
1050 | If you are short on IPs and don't want to comsume two per UML, then | 1023 | If you are short on IPs and don't want to consume two per UML, then |
1051 | you can reuse the host's eth IP address for the host ends of the tap | 1024 | you can reuse the host's eth IP address for the host ends of the tap |
1052 | devices. Internally, the UMLs must still get unique IPs for their eth | 1025 | devices. Internally, the UMLs must still get unique IPs for their eth |
1053 | devices. You can also give the UMLs non-routable IPs (192.168.x.x or | 1026 | devices. You can also give the UMLs non-routable IPs (192.168.x.x or |
@@ -2058,7 +2031,7 @@ | |||
2058 | there are multiple COWs associated with a backing file, a -d merge of | 2031 | there are multiple COWs associated with a backing file, a -d merge of |
2059 | one of them will invalidate all of the others. However, it is | 2032 | one of them will invalidate all of the others. However, it is |
2060 | convenient if you're short of disk space, and it should also be | 2033 | convenient if you're short of disk space, and it should also be |
2061 | noticably faster than a non-destructive merge. | 2034 | noticeably faster than a non-destructive merge. |
2062 | 2035 | ||
2063 | 2036 | ||
2064 | 2037 | ||
@@ -3898,29 +3871,6 @@ | |||
3898 | 3871 | ||
3899 | 3872 | ||
3900 | 3873 | ||
3901 | 1133..22.. UUMMLL hhaannggss oonn bboooott aafftteerr mmoouunnttiinngg ddeevvffss | ||
3902 | |||
3903 | The boot looks like this: | ||
3904 | |||
3905 | |||
3906 | VFS: Mounted root (ext2 filesystem) readonly. | ||
3907 | Mounted devfs on /dev | ||
3908 | |||
3909 | |||
3910 | |||
3911 | |||
3912 | You're probably running a recent distribution on an old machine. I | ||
3913 | saw this with the RH7.1 filesystem running on a Pentium. The shared | ||
3914 | library loader, ld.so, was executing an instruction (cmove) which the | ||
3915 | Pentium didn't support. That instruction was apparently added later. | ||
3916 | If you run UML under the debugger, you'll see the hang caused by one | ||
3917 | instruction causing an infinite SIGILL stream. | ||
3918 | |||
3919 | |||
3920 | The fix is to boot UML on an older filesystem. | ||
3921 | |||
3922 | |||
3923 | |||
3924 | 1133..33.. AA vvaarriieettyy ooff ppaanniiccss aanndd hhaannggss wwiitthh //ttmmpp oonn aa rreeiisseerrffss ffiilleessyyss-- | 3874 | 1133..33.. AA vvaarriieettyy ooff ppaanniiccss aanndd hhaannggss wwiitthh //ttmmpp oonn aa rreeiisseerrffss ffiilleessyyss-- |
3925 | tteemm | 3875 | tteemm |
3926 | 3876 | ||
@@ -3953,9 +3903,9 @@ | |||
3953 | 3903 | ||
3954 | 1133..55.. UUMMLL ddooeessnn''tt wwoorrkk wwhheenn //ttmmpp iiss aann NNFFSS ffiilleessyysstteemm | 3904 | 1133..55.. UUMMLL ddooeessnn''tt wwoorrkk wwhheenn //ttmmpp iiss aann NNFFSS ffiilleessyysstteemm |
3955 | 3905 | ||
3956 | This seems to be a similar situation with the resierfs problem above. | 3906 | This seems to be a similar situation with the ReiserFS problem above. |
3957 | Some versions of NFS seems not to handle mmap correctly, which UML | 3907 | Some versions of NFS seems not to handle mmap correctly, which UML |
3958 | depends on. The workaround is have /tmp be non-NFS directory. | 3908 | depends on. The workaround is have /tmp be a non-NFS directory. |
3959 | 3909 | ||
3960 | 3910 | ||
3961 | 1133..66.. UUMMLL hhaannggss oonn bboooott wwhheenn ccoommppiilleedd wwiitthh ggpprrooff ssuuppppoorrtt | 3911 | 1133..66.. UUMMLL hhaannggss oonn bboooott wwhheenn ccoommppiilleedd wwiitthh ggpprrooff ssuuppppoorrtt |
@@ -4022,7 +3972,7 @@ | |||
4022 | nneett | 3972 | nneett |
4023 | 3973 | ||
4024 | If you can connect to the host, and the host can connect to UML, but | 3974 | If you can connect to the host, and the host can connect to UML, but |
4025 | you can not connect to any other machines, then you may need to enable | 3975 | you cannot connect to any other machines, then you may need to enable |
4026 | IP Masquerading on the host. Usually this is only experienced when | 3976 | IP Masquerading on the host. Usually this is only experienced when |
4027 | using private IP addresses (192.168.x.x or 10.x.x.x) for host/UML | 3977 | using private IP addresses (192.168.x.x or 10.x.x.x) for host/UML |
4028 | networking, rather than the public address space that your host is | 3978 | networking, rather than the public address space that your host is |
@@ -4671,7 +4621,7 @@ | |||
4671 | Chris Reahard built a specialized root filesystem for running a DNS | 4621 | Chris Reahard built a specialized root filesystem for running a DNS |
4672 | server jailed inside UML. It's available from the download | 4622 | server jailed inside UML. It's available from the download |
4673 | <http://user-mode-linux.sourceforge.net/dl-sf.html> page in the Jail | 4623 | <http://user-mode-linux.sourceforge.net/dl-sf.html> page in the Jail |
4674 | Filesysems section. | 4624 | Filesystems section. |
4675 | 4625 | ||
4676 | 4626 | ||
4677 | 4627 | ||