[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] [Xen-devel] [PATCH] Recover from corrupt tdb on reboot
This patch was created for 3.1.0. Based on inspection, I believe the current version has the same problem, but I did not actually try it. I hope you'll find the patch useful anyway. Xen cannot work when xenstored's tdb is corrupt. When that happens somehow (and we've seen it happen), even reboot doesn't recover from it. It could: there is no state in tdb that needs to be persisted across reboots. The appended patch arranges that tdb is removed before xenstored is started, provided it doesn't already run. This is safe, because: * xenstored cannot be restarted. If it dies, Xen's screwed until reboot. * /usr/sbin/xend always starts xenstored anyway. * xenstored locks its pid-file (see write_pidfile() in tools/xenstore/xenstored_core.c), and refuses to start when it can't. * My patch makes /usr/sbin/xend remove tdb iff it can lock the pid-file. In other words, it removes tdb only when xenstored is not running, and locks it out until it is done. Bonus fix: it also removes stale copies of the tdb xenstored tends to leave behind when it exits uncleanly. Signed-off-by: Markus Armbruster <armbru@xxxxxxxxxx> diff -r 3191627e5ad6 tools/misc/xend --- a/tools/misc/xend Wed Oct 31 16:21:18 2007 +0000 +++ b/tools/misc/xend Mon Nov 05 18:23:11 2007 +0100 @@ -23,6 +23,8 @@ On Solaris, the daemons are SMF managed, and you should not attempt to start xend by hand. """ +import fcntl +import glob import os import os.path import sys @@ -76,6 +78,23 @@ def check_user(): raise CheckError("invalid user") def start_xenstored(): + pidfname = "/var/run/xenstore.pid" + try: + f = open(pidfname, "a") + try: + fcntl.lockf(f, fcntl.LOCK_EX | fcntl.LOCK_NB) + rootdir = os.getenv("XENSTORED_ROOTDIR") or "/var/lib/xenstored" + for i in glob.glob(rootdir + "/tdb*"): + try: + os.unlink(i) + except: + pass + os.unlink(pidfname) + except: + pass + f.close() + except: + pass XENSTORED_TRACE = os.getenv("XENSTORED_TRACE") cmd = "xenstored --pid-file /var/run/xenstore.pid" if XENSTORED_TRACE: _______________________________________________ Xen-devel mailing list Xen-devel@xxxxxxxxxxxxxxxxxxx http://lists.xensource.com/xen-devel
|
Lists.xenproject.org is hosted with RackSpace, monitoring our |