Core Dump Error Message

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KrazyBob
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Core Dump Error Message

Unread post by KrazyBob »

I am really out of my league these days. My newest Plesk Virtuozzo 4.7 server has just started spitting out this error message and I cannot find any reference to it in Google. It helps to know "what" to type. I am unable to get a backup off of the server because the load goes very, very high. It backups up less than 10G of 72G and starts over. I cannot even use vzmigrate to move the container without a high load. Virtuozzo does not support the --lazy flag anymore. Without a recent backup I am terrified to reboot the server. The error message tells me that it is trying to abort from a failed command and suggests a kernel issue. But I am wondering if a reboot is safe without a current backup.

Suggestions?

Code: Select all

[26138940.488268] Core dump to |/usr/libexec/abrt-hook-ccpp 11 0 20089 0 0 1413607761 e pipe failed
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mikeshinn
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Re: Core Dump Error Message

Unread post by mikeshinn »

I can only speak to the abrt message, that means some application died and core dumped and sent it to the redhat "abrt" daemon which collects debug information for redhat.
faris
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Re: Core Dump Error Message

Unread post by faris »

I used to see this all over the place in the logs on our VZ machines. You can stop this by stopping the abrtd service (and at least one other service starting with abrt if I recall correctly).

In *my case* abrtd was complaining because it didn't have enough room in, I think, /boot to save the core dump. You can change the location but I never bothered.

And the core dumps were, I think, a result of a running program being killed by VZ due to OOM within a container - at least in my case that's what was happening. So it wasn't VZ itself erroring/failing, but something running in a container. It could equally be something running on the HN itself, or in the service container mind you (e.g. the backup!)

Check for OOMs within container that happen at the same time as these to confirm this. They should be visible in /var/log/messages in the HN.

Please note the usual "I think"s and "in my case"s here!!! ;-) I don't want to be responsible for causing you more stress or problems.
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Re: Core Dump Error Message

Unread post by KrazyBob »

You guys are great! Funny, too, Faris. LOL.

My big issue is that I cannot run a backup. I try and the load skyrockets to, in last nights case, 88. I found the offending container and noted that the customer has moved a lot of CGI and Python scripts onto a Plesk 11 server. But I think that before I can reboot the server I MUST make backups and it won't let me. Sadly I noted this problem when I saw that a good backup hasn't run since July. I never got an error email and discovered that Outlook/Norton had flagged the email as SPAM. Dammit!

I have tried the CLI using:

Code: Select all

vzbackup -I -Cg --no-split 192.168.220.106 -e 113
but all I get is a high load.

Next I tried using the vzback.conf file and:

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vzbackup -I -p --no-split 192.168.220.106 -e 113
to force the max_load_avg to be followed but I end up with a zero byte backup that doesn't complete.

Lastly I tried just using:

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vzbackup -p 192.168.220.106
even though it doesn't allow me, from what I have read, to specify --nosplit.

Bottom line: no backups!

Next recourse is to use vzmigrate and move the containers to another server without shutting them off but VZ 4.7 doesn't allow the --lazy flag:

Code: Select all

vzmigrate -r no --online --lazy --keep-dst 192.168.220.104 113
[code]

If I drop off the --lazy I again get a high load. I suspect that the server needs to be rebooted but once again without a backup I'm hosed.

So I guess now is the time to ask what some alternate command lines might work. In the past I have always used just a simple command line but as I stated it stopped working and I didn't notice w/o an error email.
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Re: Core Dump Error Message

Unread post by mikeshinn »

I try and the load skyrockets to, in last nights case, 88
Is the load from I/O or something else?
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Re: Core Dump Error Message

Unread post by KrazyBob »

I don't know or how to find out. I can say that it won't let me backup the entire server using vzbackup, or migrate it using vzmigrate and the flags I am setting.

What vzmigrate flags do you recommend?
faris
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Re: Core Dump Error Message

Unread post by faris »

how about shutting the container down and trying the backup again?

iotop is a great tool for checking what's eating your I/O, as it htop

I think both are in the rpmforge repo and work fine with VZ.

iotop is the simplest:
# iotop -oaP

o = only running stuff
a = accumulative (press A to toggle accumulative on and off. when on, it keeps the processes with the most accumulated disk io at the top)
P = show processes not threads

Things to look out for: syslog/rsyslog using a lot of IO. Nothing much you can do about it usually, but it is a bit of an indication that disk io isn't brilliant

You can also use ionice to reduce the IO priority of a process (e.g. backup) to help prevent the high load if it is to do with IO.

ionice -n [0-7] -p [PID]

See http://www.cyberciti.biz/tips/linux-set ... ority.html

Also look at vzstat which can be very useful.

I don't use vzbackup anymore but I never did anything different about it other than increasing the timeout somewhere in one conf file or other.
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faris
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Re: Core Dump Error Message

Unread post by faris »

oh, hang on. you said VZ4.7? Try using vzabackup instead of vzbackup to see if it makes any difference.
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Re: Core Dump Error Message

Unread post by KrazyBob »

You are an excellent resource! I tried using vzabackup but it doesn't like the --nosplit flag. Do you allow multi-part backups, which I don't? I prefer one backup file. I use this:

Code: Select all

vzabackup -I -p --no-split 192.168.220.106 -e 113
but again it doesn't like the nosplit and the load still goes upwards to ~100. I am pretty sure that there is a failed app and I need to do a reboot. But I am afraid to do so without a current backup.

Using vzabackup required me to login even though I have a key set and vzbackup doesn't require me to login.

As soon as I ran vzabackup the load shot to 70 and I don't know how I aborted it.

Containers are being served. Would you consider rebooting the server without a current backup?

What is a sample command line for vzmigrate, please? It doesn't have a --lazy option that I can nurse along.
faris
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Re: Core Dump Error Message

Unread post by faris »

Yeah, vzabackup doesn't have a split option.

I think you can just do something like this:

vzmigrate -r no root@destination-node CTID

-r no means keep a copy of the container on the source node. Makes moving it back really quick.

The main options is:
--online (which reduces downtime, and doesn't reboot the CT - user doesn't know anything happened. Doesn't always work, and requires certain modules to be present on both nodes to work, which aren't installed as standard)
--dry-run (does what it says on the tin)


For vzabackup from one server to another, you'd typically do something like (I think the syntax is correct, otherwise double-check with man vzabackup)

vzabackup -F root@source-node --storage root@storage-node -e CTID

Otherwise omit --storage root@storage-node
Also you can use --force to ignore errors.

And yes, *I* would reboot without the backup (but this doesn't mean you should!).
I'd try restarting the container first. If it restarts then you know it will reboot on HN boot unless you have a disk failure. If it doesn't restart then you know a backup would not do you any good and there's some sort of damage in the container that needs addressing anyway. That's my logic anyway.


Incidentally, have you tried Cloning the container? That would effectively be a backup. Just make sure it isn't set to run at boot or after Clone creation.
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Re: Core Dump Error Message

Unread post by KrazyBob »

I am most worried that there is a disk problem, although dmesg is clear except for the abrt-hook lines.

Any attempt to backup the node gives me a high CPU. VSTAT tells me that I am out of swap space but I don't know why. The sever is intended for two VZ containers using dual AMD 248 Opteron's and 4GB of RAM. This has worked for years. But it looks like the client has moved a lot of web sites onto one of the nodes that I didn't know about. I am terrified to do a reboot without a current backup.
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Re: Core Dump Error Message

Unread post by faris »

well, do a backup with the container shut down. If that still doesn't work.....try excluding /var/named from the backup (there are some circular references in there or something)
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Re: Core Dump Error Message

Unread post by KrazyBob »

Will do, and thank you for taking the time to reply. I don't mind reading the manuals (although Plesk has one for turning rack mount screws - LOL) but I will. I don't mind getting dirty. But I will. It is just when I am stumped I ask for help.

I have been watching VZSTAT for a couple of days and I've noticed that Plesk 11 and 12 seem to setup PHP to run as a CGI or Python resulting in heavy loads. Mailman is one with its gate_news cron.

These are two small Plesk 11 servers that had cron's setup for backing them up. It appears that my SPAM filter was snagging the results email telling me that the backup had failed.

Code: Select all

 10:31am, up 306 days,  1:31,  1 user, load average: 0.64, 0.58, 0.69
CTNum 3, procs  504: R   4, S  498, D   0, Z   2, T   0, X   0
CPU [ OK ]: CTs  97%, CT0   0%, user  39%, sys  12%, idle  49%, lat(ms)   9/0
Mem [ OK ]: total 3820MB, free 173MB, lat(ms) 1/0
  ZONE0 (DMA): size 14MB, act 4MB, inact 2MB, free 7MB (0/0/0)
  ZONE1 (DMA32): size 2992MB, act 947MB, inact 695MB, free 163MB (5/7/8)
  ZONE2 (Normal): size 1008MB, act 229MB, inact 40MB, free 2MB (1/2/2)
  Mem lat (ms): A0 0, K0 0, U0 1, K1 0, U1 0
  Slab pages: 161MB/161MB (ino 59MB, de 0MB, bh 10MB, pb 0MB)
Swap [ OK ]: tot 12287MB, free 11464MB, in 0.000MB/s, out 0.000MB/s
Net [ OK ]: tot: in  0.004MB/s   45pkt/s, out  0.033MB/s   46pkt/s
             lo: in  0.000MB/s    0pkt/s, out  0.000MB/s    0pkt/s
           eth0: in  0.004MB/s   45pkt/s, out  0.033MB/s   46pkt/s
           eth1: in  0.000MB/s    0pkt/s, out  0.000MB/s    0pkt/s
Disks [ OK ]: in 0.023MB/s, out 0.000MB/s

  CTID ST   %VM    %KM        PROC     CPU     SOCK FCNT MLAT IP
     1 OK 0.0/6.7 0.0/0.3    0/3/240 0.00/33   20/720    0     0    xx.xx.xx
   113 OK  23/54  1.4/MAX  0/154/MAX 0.21/33  303/MAX    0    xx.xx.xx
   206 OK  27/54  1.1/MAX  0/103/MAX 48.7/33  207/MAX    0    xx.xx.xx



[root@hw006 vz-scripts]# cat 113.conf 
#This is an example configuration file for so-called "basic" Container.
#<agent>: Configuration file for allocating 256 Mb of memory.
#
# Copyright (C) Parallels, 1999-2010. All rights reserved.

VERSION="2"

ONBOOT="yes"

PHYSPAGES="524288:524288"
SWAPPAGES="262144"
VM_OVERCOMMIT="1.5"

CPUUNITS="1000"

DISKSPACE="262144000:362144000"
DISKINODES="13495934:14845528"
QUOTATIME="0"
OFFLINE_MANAGEMENT="yes"
IP_ADDRESS="blanked for security"

ARCH="x86_64"
PLATFORM="linux"
VE_ROOT="/vz/root/$VEID"
VE_PRIVATE="/vz/private/$VEID"
OSTEMPLATE=".centos-6-x86_64"
DISTRIBUTION="redhat-el6"
TECHNOLOGIES="x86_64 nptl"
ORIGIN_SAMPLE="2048"
VEFORMAT="vz4"
VEID="113"
HOSTNAME="blanked for security"
NAMESERVER="4.2.2.1 4.2.2.2"
CONFIG_CUSTOMIZED="yes"
OFFLINE_SERVICE="vzpp"
DISABLED="no"
TEMPLATES=""
QUOTAUGIDLIMIT="950"
PRIVVMPAGES="2597004:2607396"



[root@hw006 vz-scripts]# cat /proc/user_beancounters 
Version: 2.5
       uid  resource                     held              maxheld              barrier                limit              failcnt
      206:  kmemsize                 43791991             44679168  9223372036854775807  9223372036854775807                    0
            lockedpages                     0                    0               524288               524288                    0
            privvmpages                387307               396542              1179648              1179648                    0
            shmpages                      551                  551  9223372036854775807  9223372036854775807                    0
            dummy                           0                    0  9223372036854775807  9223372036854775807                    0
            numproc                       102                  111  9223372036854775807  9223372036854775807                    0
            physpages                  260980               265069               524288               524288                    0
            vmguarpages                     0                    0               786432               786432                    0
            oomguarpages               244689               245048               524288               524288                    0
            numtcpsock                     38                   41  9223372036854775807  9223372036854775807                    0
            numflock                       15                   19  9223372036854775807  9223372036854775807                    0
            numpty                          0                    0  9223372036854775807  9223372036854775807                    0
            numsiginfo                      0                    6  9223372036854775807  9223372036854775807                    0
            tcpsndbuf                 1170792              1308264  9223372036854775807  9223372036854775807                    0
            tcprcvbuf                  622592               671744  9223372036854775807  9223372036854775807                    0
            othersockbuf               246608               546720  9223372036854775807  9223372036854775807                    0
            dgramrcvbuf                     0                 2312  9223372036854775807  9223372036854775807                    0
            numothersock                  171                  181  9223372036854775807  9223372036854775807                    0
            dcachesize               19927179             19935234  9223372036854775807  9223372036854775807                    0
            numfile                      4546                 4605  9223372036854775807  9223372036854775807                    0
            dummy                           0                    0  9223372036854775807  9223372036854775807                    0
            dummy                           0                    0  9223372036854775807  9223372036854775807                    0
            dummy                           0                    0  9223372036854775807  9223372036854775807                    0
            numiptent                      14                   14  9223372036854775807  9223372036854775807                    0
      113:  kmemsize                 53467299             54534144  9223372036854775807  9223372036854775807                    0
            lockedpages                     0                    0               524288               524288                    0
            privvmpages                729538               730176              2597004              2607396                    0
            shmpages                      695                  695  9223372036854775807  9223372036854775807                    0
            dummy                           0                    0  9223372036854775807  9223372036854775807                    0
            numproc                       156                  165  9223372036854775807  9223372036854775807                    0
            physpages                  234175               235196               524288               524288                    0
            vmguarpages                     0                    0               786432               786432                    0
            oomguarpages               219726               219991               524288               524288                    0
            numtcpsock                     63                   72  9223372036854775807  9223372036854775807                    0
            numflock                       16                   21  9223372036854775807  9223372036854775807                    0
            numpty                          0                    0  9223372036854775807  9223372036854775807                    0
            numsiginfo                      0                    6  9223372036854775807  9223372036854775807                    0
            tcpsndbuf                 1197216              1823800  9223372036854775807  9223372036854775807                    0
            tcprcvbuf                 1032192              1179648  9223372036854775807  9223372036854775807                    0
            othersockbuf               357024               473808  9223372036854775807  9223372036854775807                    0
            dgramrcvbuf                     0                 2312  9223372036854775807  9223372036854775807                    0
            numothersock                  240                  248  9223372036854775807  9223372036854775807                    0
            dcachesize               16414765             16437408  9223372036854775807  9223372036854775807                    0
            numfile                      4636                 4915  9223372036854775807  9223372036854775807                    0
            dummy                           0                    0  9223372036854775807  9223372036854775807                    0
            dummy                           0                    0  9223372036854775807  9223372036854775807                    0
            dummy                           0                    0  9223372036854775807  9223372036854775807                    0
            numiptent                      14                   14  9223372036854775807  9223372036854775807                    0
        1:  kmemsize                   420826               843776             11055923             11377049                    0
            lockedpages                     0                    0                  256                  256                    0
            privvmpages                    61                  513                65536                69632                    0
            shmpages                        0                    0                21504                21504                    0
            dummy                           0                    0  9223372036854775807  9223372036854775807                    0
            numproc                         3                    9                  240                  240                    0
            physpages                     104                  968                65536                65536                    0
            vmguarpages                     0                    0                33792           2147483647                    0
            oomguarpages                   13                   16                26112           2147483647                    0
            numtcpsock                      2                    6                  360                  360                    0
            numflock                        0                    0                  188                  206                    0
            numpty                          0                    0                   16                   16                    0
            numsiginfo                      0                    0                  256                  256                    0
            tcpsndbuf                   34880               104640              1720320              2703360                    0
            tcprcvbuf                   32768                98304              1720320              2703360                    0
            othersockbuf                    0                 8456              1126080              2097152                    0
            dgramrcvbuf                     0                    0               262144               262144                    0
            numothersock                   18                   19                  360                  360                    0
            dcachesize                  30063                61023              3409920              3624960                    0
            numfile                         5                   20                 9312                 9312                    0
            dummy                           0                    0  9223372036854775807  9223372036854775807                    0
            dummy                           0                    0  9223372036854775807  9223372036854775807                    0
            dummy                           0                    0  9223372036854775807  9223372036854775807                    0
            numiptent                      14                   14                  128                  128                    0
        0:  kmemsize                 97224576            587595776  9223372036854775807  9223372036854775807                    0
            lockedpages                370860               370860  9223372036854775807  9223372036854775807                    0
            privvmpages                571780              2563497  9223372036854775807  9223372036854775807                    0
            shmpages                      957                16702  9223372036854775807  9223372036854775807                    0
            dummy                           0                    0  9223372036854775807  9223372036854775807                    0
            numproc                       245                  274  9223372036854775807  9223372036854775807                    0
            physpages                  417657               805377  9223372036854775807  9223372036854775807                    0
            vmguarpages                     0                    0                    0                    0                    0
            oomguarpages               425617               519328  9223372036854775807  9223372036854775807                    0
            numtcpsock                     28                   45  9223372036854775807  9223372036854775807                    0
            numflock                        8                   18  9223372036854775807  9223372036854775807                    0
            numpty                          1                    3  9223372036854775807  9223372036854775807                    0
            numsiginfo                      1                  135  9223372036854775807  9223372036854775807                    0
            tcpsndbuf                  505760              3638192  9223372036854775807  9223372036854775807                    0
            tcprcvbuf                  458752               737280  9223372036854775807  9223372036854775807                    0
            othersockbuf               397664               762208  9223372036854775807  9223372036854775807                    0
            dgramrcvbuf                     0                16744  9223372036854775807  9223372036854775807                    0
            numothersock                  263                  310  9223372036854775807  9223372036854775807                    0
            dcachesize               50072906            546476318  9223372036854775807  9223372036854775807                    0
            numfile                      1433                 1995  9223372036854775807  9223372036854775807                    0
            dummy                           0                    0  9223372036854775807  9223372036854775807                    0
            dummy                           0                    0  9223372036854775807  9223372036854775807                    0
            dummy                           0                    0  9223372036854775807  9223372036854775807                    0
            numiptent                      20                   20  9223372036854775807  9223372036854775807                    0
faris
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Re: Core Dump Error Message

Unread post by faris »

Press "0" when looking at vzstat to see the HN's own stats (listed as Container 0). Also try pressing "a" which gives you an average rather than an instantaneous figure.

Looks healthy to me though.
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Re: Core Dump Error Message

Unread post by KrazyBob »

A backup was impossible so I crossed my fingers and did a successful reboot. But dammit. Plesk won't let me put in a cron and forces me to login. But yet my key works if I ssh in. I'm trying to do a kernel update but vzup2date doesn't seem to have it. I need to spend more time in here but I am injured and bedridden. Typing is difficult.
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