rsync and CVS exclude

The CVS exclude option of rsync can be harm­ful in some cases.

For exam­ple I use rsync to keep my/this web­site updat­ed. At some point I noticed some strange behav­ior after the update of sev­er­al of the Word­Press plu­g­ins I use. After a bit of inves­ti­ga­tion I noticed that one plu­g­in (Bro­ken Link Check­er) has a direc­to­ry which is named “core”. This is one of the file­names which are in the exclude list of the CVS exclude fea­ture of rsync. Nor­mal­ly it should only pre­vent the trans­fer of core-files, but as rsync does not have a look if this is a file or a direc­to­ry (it is not sup­posed to do this), it also pre­vents the trans­mis­sion of the directory.

After mod­i­fy­ing the rsync options to man­u­al­ly exclude the CVS pat­terns except for “core”, the site worked cor­rect­ly again.

It seems this is one of those cas­es where dif­fer­ent development/management cul­tures show some lit­tle incompatibilities.

EMC^2/Legato Net­work­er 7.5.1.4 tests

Regard­ing our last prob­lems with NW:

  • OK: the “restart NW-server direct­ly after delet­ing a client with index entries”-crash is fixed
  • Most­ly OK: shut­ting down a stor­age node does not crash the NW-server any­more… most of the time (some­times there is some strange behav­ior in this regard, we do not have enough evi­dence, but there may be still some sleep­ing dragons)
  • ?: we did not yet check the dis­as­ter recov­er part
  • NOK: the post-cmd is still run one minute after the pre-cmd in some cas­es, maybe this is relat­ed to a session/save-set which is not yet start­ed but the pre-cmd is already run, if this is the case, this could maybe also affect the case where there is more than one minute of delay between the end of one session/save-set on a machine and the start of anoth­er session/save-set on the same machine (the sup­port is investigating)
  • NOK: some Oracle-RMAN back­ups (cus­tom save com­mand, perl script) show a run­ning ses­sion in the NW-monitoring and some do not, after the back­up mmin­fo some­times lists the group of a RMAN-save-set and some­times not (for the same client), under inves­ti­ga­tion by the support

So, for us 7.5.1.4 is still a beta version.

Lin­ux­u­la­tor in ‑cur­rent ready for test­ing the 2.6.16 emulation

Today I com­mit­ted two patch­es which fix the last two pan­ics we know about in the 2.6.16 emu­la­tion. Now we need testers. Here’s the text of the mail I did send to current@ a few moments ago:

Hi,

today I com­mit­ted the last fix­es for the show­stop­per prob­lems (pan­ics) in the lin­ux 2.6.16 emu­la­tion. I intend to switch the default ver­sion to 2.6.16 on i386 “soon” (see below), so please help test­ing it.

More recent lin­ux dis­tri­b­u­tions (e.g. FC5) require a 2.6 ker­nel and don’t work with 2.4.2 any­more. And because FC4 is “abandon-ware” (no secu­ri­ty fix­es from fedo­rale­ga­cy any­more), get­ting 2.6.16 emu­la­tion up an run­ning is very important.

If you use a lin­ux pro­gram, please add compat.linux.osrelease=2.6.16 to /etc/sysctl.conf (my desk­top is run­ning with 2.6.16 emu­la­tion since some days already). After the next boot (or after run­ning “sysctl compat.linux.osrelease=2.6.16”, please make sure no lin­ux pro­gram is run­ning already) any lin­ux pro­gram will start with a lin­ux ker­nel ver­sion of 2.6.16 instead of 2.4.2. The default lin­ux base port (FC4) will then use dif­fer­ent code paths (e.g. with­in glibc). In case you want to switch back to the 2.4.2 emu­la­tion with­out a reboot, please make sure no lin­ux pro­gram is run­ning anymore.

So far we fixed all known/repeatable prob­lems with acrore­ad, realplay­er, skype and lin­ux fire­fox. If you encounter strange behav­ior with any lin­ux pro­gram, please tell us (emulation@freebsd.org) which pro­gram you used, how to repeat the prob­lem, what the prob­lem is, and if it only is vis­i­ble with 2.6.16 or with 2.4.2 too. You should also watch out for mes­sages in the dmesg (unim­ple­ment­ed sys­tem calls or oth­er stuff, this is used to deter­mine the pri­or­i­ty of miss­ing syscalls). Please also have a look at http://wiki.FreeBSD.org/linux-kernel, I intend to doc­u­ment the known prob­lems there. If you find your prob­lem there, please tell us about it if you are will­ing to test fixes.

We are spe­cial­ly inter­est­ed in reports (good or bad) on SMP sys­tems. Please beat the hell out of the linuxulator!

On amd64 sys­tems we have not the same func­tion­al­i­ty as on i386, miss­ing are futex­es and TLS. In P4 we already have the futex part cov­ered, but the TLS part is still miss­ing (any­one with a clue about the ker­nel side of TLS on amd64 is wel­come to give a hint or two to jkim@ and rdivacky@). So if you get a mes­sage about miss­ing futex­es or TLS on amd64: we know about it (testers for the futex stuff are wel­come, but first you need to use a pro­gram which uses futex­es and complains).

As long as we get prob­lem reports with 2.6.16 I will not switch the default to 2.6.16. If we don’t get a report at all, I will switch the default on i386 to 2.6.16 in two weeks. If we get some prob­lem reports, we will push back the switch a lit­tle bit depend­ing on the sever­i­ty of the problem.

Bye,
Alexander.