Hi, I having intermittent problems which trigger the below segfault. Would love to know what the problem is, and will gladly take any suggestions as to how to troubleshoot this. When this segfault happen, the windows clients sometimes report "write delay failed". This machine is an OpenVZ virtual machine, with a bridged interface. Samba version: 3.0.22-1ubuntu3.6 (ubuntu dapper with custom OpenVZ kernel) kernel: 2.6.18-028stab053 Filesystem is xfs with noatime on. mount output: simfs on / type simfs (rw,noatime) proc on /proc type proc (rw) sysfs on /sys type sysfs (rw) devpts on /dev/pts type devpts (rw) tmpfs on /dev/shm type tmpfs (rw) varrun on /var/run type tmpfs (rw) varlock on /var/lock type tmpfs (rw) xfs filesystem is on top of a Raid1 md device on the host, with the members provided by AoE. I don't think the segfaults correspond to the occasional AoE retransmits we get. All networking is gigabit, and this system was stress tested with dbench before going into production, and worked pretty well. Host has plenty of ram, and nothing else segfaults, so I don't think its a hardware problem, though I wouldn't rule out an interaction problem with Samba/XFS/OpenVZ/md-RAID1/AoE at this stage. As you can see it points at a windows server for authentication. I have recently increased the winbind cache time to 900, in an effort to fix, but to no avail. Across about 150 client machines getting about 10 segfaults a day, each with this error. No particular pattern to the segfaults, and nothing sticks out about the users/uid etc of the users affected (seems to be everyone and anyone at random). Setting loglevel to 10 for a specific machine doesn't seem to provide any extra information for this problem. getting this segfault which triggers a panic action intermittently: Using host libthread_db library "/lib/libthread_db.so.1". [Thread debugging using libthread_db enabled] [New Thread 47979553320704 (LWP 7785)] 0x00002ba31bd930c4 in waitpid () from /lib/libc.so.6 #0 0x00002ba31bd930c4 in waitpid () from /lib/libc.so.6 #1 0x00002ba31bd3d5ff in strtold_l () from /lib/libc.so.6 #2 0x00000000005c1374 in smb_panic2 (why=0x6ac813 "failed to set uid\n", decrement_pid_count=<value optimized out>) at lib/util.c:1545 #3 0x00000000005c60d8 in assert_uid (ruid=4294967295, euid=10122) at lib/util_sec.c:96 #4 0x000000000049235e in become_id (uid=10122, gid=10000) at smbd/sec_ctx.c:60 #5 0x0000000000492c8c in pop_sec_ctx () at smbd/sec_ctx.c:375 #6 0x000000000048a579 in unbecome_root () at smbd/uid.c:435 #7 0x00000000005eeaf1 in reply_to_oplock_break_requests (fsp=0x8de810) at smbd/oplock.c:683 #8 0x0000000000490601 in close_file (fsp=0x8de810, normal_close=1) at smbd/close.c:228 #9 0x0000000000471ba7 in reply_close (conn=0x8d8390, inbuf=0x2ba31a5a3010 "", outbuf=0x2ba31a5c4010 "", size=<value optimized out>, dum_buffsize=<value optimized out>) at smbd/reply.c:3286 #10 0x00000000004a111a in switch_message (type=4, inbuf=0x2ba31a5a3010 "", outbuf=0x2ba31a5c4010 "", size=45, bufsize=131072) at smbd/process.c:1071 #11 0x00000000004a15f0 in process_smb (inbuf=0x2ba31a5a3010 "", outbuf=0x2ba31a5c4010 "") at smbd/process.c:1101 #12 0x00000000004a24a4 in smbd_process () at smbd/process.c:1753 #13 0x0000000000645a39 in main (argc=23, argv=0x7fff905b09a0) at smbd/server.c:976 I have tried to reproduce the problem by stressing the system further, but to no avail. It does not appear related to system load etc, but happens at random. The machine is a profile server for Firefox and Thunderbird, so lots of small files are opening and closing etc. Here is my testparm -v: Domain replaced with (XXX) root@mrforgetful:/var/log/samba # testparm -v Load smb config files from /etc/samba/smb.conf Can't find include file /etc/samba/smb.conf. Processing section "[homes]" Processing section "[public]" Processing section "[win]" Processing section "[vmware]" Processing section "[gap_backup]" Processing section "[iso]" Processing section "[pictures]" Loaded services file OK. WARNING: passdb expand explicit = yes is deprecated 'winbind separator = +' might cause problems with group membership. Server role: ROLE_DOMAIN_MEMBER Press enter to see a dump of your service definitions [global] dos charset = CP850 unix charset = UTF-8 display charset = LOCALE workgroup = XXX realm = XXX.XXX.COM.AU netbios name = MRFORGETFUL netbios aliases netbios scope server string interfaces bind interfaces only = No security = ADS auth methods encrypt passwords = Yes update encrypted = No client schannel = Auto server schannel = Auto allow trusted domains = Yes hosts equiv map to guest = Never null passwords = No obey pam restrictions = Yes password server = xxxserver smb passwd file = /etc/samba/smbpasswd private dir = /etc/samba passdb backend = smbpasswd algorithmic rid base = 10000 root directory guest account = nobody enable privileges = No pam password change = No passwd program = /usr/bin/passwd %u passwd chat = *Enter\snew\sUNIX\spassword:* %n\n *Retype\snew\sUNIX\spassword:* %n\n . passwd chat debug = No passwd chat timeout = 2 check password script username map password level = 0 username level = 0 unix password sync = No restrict anonymous = 0 lanman auth = Yes ntlm auth = Yes client NTLMv2 auth = No client lanman auth = Yes client plaintext auth = Yes preload modules use kerberos keytab = No log level = 0 syslog = 0 syslog only = No log file = /var/log/samba/log.%m max log size = 1000 debug timestamp = Yes debug hires timestamp = No debug pid = No debug uid = No smb ports = 445 139 large readwrite = Yes max protocol = NT1 min protocol = CORE read bmpx = No read raw = Yes write raw = Yes disable netbios = No reset on zero vc = No acl compatibility defer sharing violations = Yes nt pipe support = Yes nt status support = Yes announce version = 4.9 announce as = NT max mux = 50 max xmit = 16644 name resolve order = lmhosts wins host bcast max ttl = 259200 max wins ttl = 518400 min wins ttl = 21600 time server = No unix extensions = Yes use spnego = Yes client signing = No server signing = No client use spnego = No enable asu support = Yes svcctl list change notify timeout = 60 deadtime = 0 getwd cache = Yes keepalive = 300 kernel change notify = Yes lpq cache time = 30 max smbd processes = 0 paranoid server security = Yes max disk size = 0 max open files = 10000 socket options = TCP_NODELAY use mmap = Yes hostname lookups = No name cache timeout = 660 load printers = No printcap cache time = 750 printcap name = /dev/null cups server iprint server disable spoolss = Yes enumports command addprinter command deleteprinter command show add printer wizard = Yes os2 driver map mangling method = hash2 mangle prefix = 1 max stat cache size = 0 stat cache = Yes machine password timeout = 604800 add user script rename user script delete user script add group script delete group script add user to group script delete user from group script set primary group script add machine script shutdown script abort shutdown script username map script logon script logon path = \\%N\%U\profile logon drive logon home = \\%N\%U domain logons = No os level = 20 lm announce = Auto lm interval = 60 preferred master = Auto local master = Yes domain master = Auto browse list = Yes enhanced browsing = Yes dns proxy = No wins proxy = No wins server wins support = No wins hook wins partners kernel oplocks = Yes lock spin count = 3 lock spin time = 10 oplock break wait time = 0 ldap admin dn ldap delete dn = No ldap group suffix ldap idmap suffix ldap machine suffix ldap passwd sync = no ldap replication sleep = 1000 ldap suffix ldap ssl ldap timeout = 15 ldap page size = 1024 ldap user suffix add share command change share command delete share command eventlog list config file preload lock directory pid directory = /var/run/samba utmp directory wtmp directory utmp = No default service message command get quota command set quota command remote announce remote browse sync socket address = 0.0.0.0 homedir map = auto.home afs username map afs token lifetime = 604800 log nt token command time offset = 0 NIS homedir = No panic action = /usr/share/samba/panic-action %d host msdfs = No enable rid algorithm = Yes passdb expand explicit = Yes idmap backend idmap uid = 10000-20000 idmap gid = 10000-20000 template homedir = /home/%D/%U template shell = /bin/false winbind separator = + winbind cache time = 900 winbind enum users = Yes winbind enum groups = Yes winbind use default domain = No winbind trusted domains only = No winbind nested groups = No winbind max idle children = 3 winbind nss info = template comment path username invalid users = root valid users admin users read list write list printer admin force user force group read only = Yes acl check permissions = Yes acl group control = No acl map full control = Yes create mask = 0744 force create mode = 00 security mask = 0777 force security mode = 00 directory mask = 0755 force directory mode = 00 directory security mask = 0777 force directory security mode = 00 force unknown acl user = No inherit permissions = No inherit acls = No inherit owner = No guest only = No guest ok = No only user = No hosts allow hosts deny allocation roundup size = 1048576 aio read size = 0 aio write size = 0 aio write behind ea support = No nt acl support = Yes profile acls = No map acl inherit = No afs share = No block size = 1024 max connections = 0 min print space = 0 strict allocate = No strict sync = No sync always = No use sendfile = No write cache size = 0 max reported print jobs = 0 max print jobs = 1000 printable = No printing = bsd cups options print command = lpr -r -P'%p' %s lpq command = lpq -P'%p' lprm command = lprm -P'%p' %j lppause command lpresume command queuepause command queueresume command printer name use client driver = No default devmode = No force printername = No default case = lower case sensitive = Auto preserve case = Yes short preserve case = Yes mangling char = ~ hide dot files = Yes hide special files = No hide unreadable = No hide unwriteable files = No delete veto files = No veto files hide files veto oplock files map archive = Yes map hidden = No map system = No map readonly = yes mangled names = Yes mangled map store dos attributes = No browseable = Yes blocking locks = Yes csc policy = manual fake oplocks = No locking = Yes oplocks = Yes level2 oplocks = Yes oplock contention limit = 2 posix locking = Yes strict locking = Yes share modes = Yes dfree cache time = 0 dfree command copy include = /etc/samba/smb.conf. preexec preexec close = No postexec root preexec root preexec close = No root postexec available = Yes volume fstype = NTFS set directory = No wide links = Yes follow symlinks = Yes dont descend magic script magic output delete readonly = No dos filemode = No dos filetimes = Yes dos filetime resolution = No fake directory create times = No vfs objects msdfs root = No msdfs proxy [homes] comment = Home Directories valid users = XXX+%S read only = No create mask = 0700 directory mask = 0700 browseable = No [public] path = /mnt/pkg/public read only = No [win] path = /mnt/pkg/win [vmware] path = /mnt/pkg/vmware [gap_backup] path = /mnt/pkg/gap_backup read only = No create mask = 0777 directory mask = 0777 [iso] path = /mnt/pkg/iso [pictures] path = /mnt/pkg/pictures