Discuss April 2009

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291 participants
340 discussions

Weird performance problem
by Ugo Bellavance 24 May '09

24 May '09

Hi, I'm running a CentOS 4. server and I sometimes face a weird problem. It is a weird performance problem, and here is how I discovered it. This server runs OpenVZ virtual machines, and one of them is an asterisk server for my personal use. The first symptom of the problem is that the voice quality became flaky. So I logged on the server to see what could be eating cpu cycles, when I ran top, it took almost one minute before top actually showed. Another hint is that when I run dstat (a monitoring utility that is a mix of iostat and vmstat and other stats), I often get a "missed xx ticks", where xx is a number. Example (current) (sorry for the wrap): ----total-cpu-usage---- -dsk/total- -net/total- ---paging-- ---system-- usr sys idl wai hiq siq| read writ| recv send| in out | int csw 3 2 93 2 0 0| 106k 273k| 0 0 | 0.2 0.4 |1039 389 3 6 91 0 0 0| 0 6416k| 276k 275k| 0 0 |2160 6822 missed 55 ticks 4 10 84 2 0 0|1200k 1992k| 82k 93k| 0 0 |1188 6275 missed 29 ticks 1 0 99 0 0 0| 0 1312k| 65k 66k| 0 0 |1050 1114 missed 38 ticks 2 1 96 0 0 0| 0 1168k| 57k 59k| 0 0 | 491 877 missed 13 ticks 3 1 94 1 0 0| 0 6016k| 181k 176k| 0 0 |2169 5996 missed 50 ticks 4 2 91 1 0 0| 28k 8744k| 216k 214k| 0 0 |2159 5438 missed 37 ticks 1 1 98 0 0 0| 0 2632k| 93k 91k| 0 0 | 983 1381 missed 34 ticks 1 1 98 1 0 0| 0 5624k| 113k 110k| 0 0 |1569 2643 missed 52 ticks 1 1 98 1 0 0| 0 2432k| 29k 28k| 0 0 | 679 647 missed 12 ticks 0 0 100 0 0 0| 0 0 | 60B 374B| 0 0 | 13 15 2 3 94 0 0 0| 0 1872k| 209k 210k| 0 0 |1375 3590 missed 30 ticks The problem is currently occuring, but it doesn't seem to be affecting voice quality for now, so I have some time to try to find the cause. The only solution I've found up to now is to reboot... But hey, this isn't a Windows 98 machine :)! I tried restarting the VZ system, which restarts all the VMs, but it didn't solve the problem. I can't tell if the problem occurs on a stock centos kernel, because the server is running production (but non-critical) virtual machines, so it is always running the openVZ kernel. So here is what I've done for now: - Top shows a load of about 0.4 - vmstat 1 10 shows this: procs -----------memory---------- ---swap-- -----io---- --system-- ----cpu---- r b swpd free buff cache si so bi bo in cs us sy id wa 0 0 592 191092 381720 537956 0 0 53 68 4 3 3 2 93 2 0 0 592 190720 381720 537956 0 0 0 0 32 60 1 1 98 0 0 0 592 191092 381720 537956 0 0 0 0 41 59 0 0 100 0 1 0 592 191092 381728 537948 0 0 0 2584 311 96 10 4 66 19 0 0 592 189968 381732 537944 0 0 0 2080 222 174 2 3 79 16 0 1 592 189968 381732 537944 0 0 0 3244 170 73 10 4 73 12 0 0 592 190216 381732 537944 0 0 0 136 76 113 1 2 93 4 0 0 592 189844 381732 537944 0 0 0 0 33 69 1 1 98 0 0 0 592 189844 381732 537944 0 0 0 0 24 32 0 0 100 0 0 0 592 190340 381732 537944 0 0 0 0 28 42 0 0 100 0 iostat -x 1 (excerpt) Device: rrqm/s wrqm/s r/s w/s rsec/s wsec/s rkB/s wkB/s avgrq-sz avgqu-sz await svctm %util sda 0.00 171.00 0.00 124.00 0.00 2368.00 0.00 1184.00 19.10 0.14 1.13 0.02 0.20 sdb 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 sdc 0.00 171.00 0.00 124.00 0.00 2368.00 0.00 1184.00 19.10 0.17 1.35 0.02 0.30 sdd 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 md0 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 md2 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 md1 0.00 0.00 0.00 294.00 0.00 2352.00 0.00 1176.00 8.00 0.00 0.00 0.00 0.00 dm-0 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 dm-1 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 dm-2 0.00 0.00 0.00 294.00 0.00 2352.00 0.00 1176.00 8.00 0.30 1.01 0.02 0.50 dm-3 0.00 0.00 0.00 294.00 0.00 2352.00 0.00 1176.00 8.00 0.30 1.01 0.02 0.50 dm-4 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 dm-5 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 dm-6 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 Any insight would be greatly appreciated. It is not critical, but I'd be glad to be able to finally pinpoint and solve the problem. Hardware: HP Netserver, software raid, SCSI disks, 1.7 GB RAM. I can provide more information if needed. Thanks, Ugo

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5.3 and XFS
by Joseph L. Casale 14 May '09

14 May '09

Looking at https://bugzilla.redhat.com/show_bug.cgi?id=469401 has me a bit unsure about the kmod for 5.3's kernel, is not expected to appear? Thanks! jlc

8 10

Upgrade mail server to new machine
by Thom Paine 11 May '09

11 May '09

I have an old RHEL3 box that I am upgrading to CentOS5. I picked up a new Dell Poweredge R200 to use for that. Is there an easy way to copy all the user accounts and existing mail from the old server to the new one? Thanks. -- -=/>Thom

6 7

5.3 on an EeePC??
by Beartooth 04 May '09

04 May '09

I have an ASUS EeePC 701 (with 2GB of RAM and an 8 GB card), on which I've installed CentOS on the hard-drive-plus-card. But it can't even use my eth0. Some one on a local LUG, where I had mentioned that other OSs did fine with all the same exact hardware, suggested that CentOS, being designed for stability rather than the bleeding edge, likely lacks drivers; so I need to get some. Anybody know what drivers (for wireless as well as ethernet cable) I need, and how/where to get ones to fit CentOS?? -- Beartooth Staffwright, PhD, Neo-Redneck Linux Convert Remember I know precious little of what I am talking about.

18 37

GFS and Small Files
by Hairul Ikmal Mohamad Fuzi 03 May '09

03 May '09

Hi all, We are running CentOS 5.2 64bit as our file server. Currently, we used GFS (with CLVM underneath it) as our filesystem (for our multiple 2TB SAN volume exports) since we plan to add more file servers (serving the same contents) later on. The issue we are facing at the moment is we found out that command such as 'ls' gives a very slow response.(e.g 3-4minutes for the outputs of ls to be printed out, or in certain cases, 20minutes or so) This is completely true especially in directories containing "large number" of small files (e.g 90000+ of 1-4kb files). The thing is, most of system users are generating these small files frequently as part of their workflow. We tried emulating the same scenario (90000+ of small files) on a ext3 partition and it gives almost the same result. I believe most of the CLVM/GFS settings done are using the defaults parameters. Additionally, we would prefer to stick to GFS (or at least ext3) as it is part of CentOS / RHEL distribution rather than changing into other small-files 'friendly' filesystems (such as XFS, ReiserFS). I'm exploring whether is there anyway we can tune the GFS parameters to make the system more responsive? I have read that we can apply 'dir_index' option to ext3 partition to speedup things, but I'm not so sure about GFS. Below are the output from "gfs_tool gettune /export/gfs" : ilimit1 = 100 ilimit1_tries = 3 ilimit1_min = 1 ilimit2 = 500 ilimit2_tries = 10 ilimit2_min = 3 demote_secs = 300 incore_log_blocks = 1024 jindex_refresh_secs = 60 depend_secs = 60 scand_secs = 5 recoverd_secs = 60 logd_secs = 1 quotad_secs = 5 inoded_secs = 15 glock_purge = 0 quota_simul_sync = 64 quota_warn_period = 10 atime_quantum = 3600 quota_quantum = 60 quota_scale = 1.0000 (1, 1) quota_enforce = 1 quota_account = 1 new_files_jdata = 0 new_files_directio = 0 max_atomic_write = 4194304 max_readahead = 262144 lockdump_size = 131072 stall_secs = 600 complain_secs = 10 reclaim_limit = 5000 entries_per_readdir = 32 prefetch_secs = 10 statfs_slots = 64 max_mhc = 10000 greedy_default = 100 greedy_quantum = 25 greedy_max = 250 rgrp_try_threshold = 100 statfs_fast = 0 TIA. .ikmal

8 7

Rsync/SSH automation problem?
by James Bensley 02 May '09

02 May '09

Hi All, I have a win2k3 server that its backing up to a CentOS 5.3 server. On the Win2k3 machine I plan to have rsync back up nightly to the CentOS server through ssh. The command I am using is as follows: rsync -vrPtz -e ssh myuser@myserver:/remote/backup/folder/ /local/backup/folder/ This all works great for the inital test except its prompts me for a password for "myuser" (as you would except) but how can I embed the password for ssh into the command line? Or can I not? Is the following some how possible: rsync -vrPtz -e ssh myuser@myserver mypassword /remote/backup/folder/ /local/backup/folder/ Or something like that? I can't find anything that says it is possible so its probably isn't but I know that some of you out there have far superior searching skills than I or hopefully, you might already know? Assuming this isn't possible as I've got that gut feeling it won't be, does anyone else have a better idea? BTW; Rsync in running on the windows box through cygwin in case you wondered or hadn't guessed ;) Many thanks, James ;) -----BEGIN GEEK CODE BLOCK----- Version: 3.1 GIT/MU/U dpu s: a--> C++>$ U+> L++> B-> P+> E?> W+++>$ N K W++ O M++>$ V- PS+++ PE++ Y+ PGP t 5 X+ R- tv+ b+> DI D+++ G+ e(+++++) h--(++) r++ z++ ------END GEEK CODE BLOCK------

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Re: [CentOS] eth0 killed when adding virtual interface and multiple NICs are present
by Kai Schaetzl 01 May '09

01 May '09

JohnS wrote on Mon, 27 Apr 2009 11:09:56 -0400: > If you don't mind when you come to an answer would you please let me > know. I am interested to know. I could not find a real solution. I had to go to another way of creating the network setup for this machine (and maybe others, I will see) and disable the network-bridge script from xen. That new solution is documented on the xen-users mailing-list. Kai -- Kai Schätzl, Berlin, Germany Get your web at Conactive Internet Services: http://www.conactive.com

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esata
by Jerry Geis 01 May '09

01 May '09

I am trying to get esata working. my lspci is below. When I plug in the disk an turn it on - dmesg reports nothing. Is it supposed to report anything like a usb disk does? Is there a module to load? My motherboard is GA-MA78GM-US2H. Jerry --------- 00:00.0 Host bridge: Advanced Micro Devices [AMD] RS780 Host Bridge 00:01.0 PCI bridge: Advanced Micro Devices [AMD] RS780 PCI to PCI bridge (int gfx) 00:0a.0 PCI bridge: Advanced Micro Devices [AMD] RS780 PCI to PCI bridge (PCIE port 5) 00:11.0 SATA controller: ATI Technologies Inc SB700/SB800 SATA Controller [AHCI mode] 00:12.0 USB Controller: ATI Technologies Inc SB700/SB800 USB OHCI0 Controller 00:12.1 USB Controller: ATI Technologies Inc SB700 USB OHCI1 Controller 00:12.2 USB Controller: ATI Technologies Inc SB700/SB800 USB EHCI Controller 00:13.0 USB Controller: ATI Technologies Inc SB700/SB800 USB OHCI0 Controller 00:13.1 USB Controller: ATI Technologies Inc SB700 USB OHCI1 Controller 00:13.2 USB Controller: ATI Technologies Inc SB700/SB800 USB EHCI Controller 00:14.0 SMBus: ATI Technologies Inc SBx00 SMBus Controller (rev 3a) 00:14.1 IDE interface: ATI Technologies Inc SB700/SB800 IDE Controller 00:14.2 Audio device: ATI Technologies Inc SBx00 Azalia (Intel HDA) 00:14.3 ISA bridge: ATI Technologies Inc SB700/SB800 LPC host controller 00:14.4 PCI bridge: ATI Technologies Inc SBx00 PCI to PCI Bridge 00:14.5 USB Controller: ATI Technologies Inc SB700/SB800 USB OHCI2 Controller 00:18.0 Host bridge: Advanced Micro Devices [AMD] Family 10h [Opteron, Athlon64, Sempron] HyperTransport Configuration 00:18.1 Host bridge: Advanced Micro Devices [AMD] Family 10h [Opteron, Athlon64, Sempron] Address Map 00:18.2 Host bridge: Advanced Micro Devices [AMD] Family 10h [Opteron, Athlon64, Sempron] DRAM Controller 00:18.3 Host bridge: Advanced Micro Devices [AMD] Family 10h [Opteron, Athlon64, Sempron] Miscellaneous Control 00:18.4 Host bridge: Advanced Micro Devices [AMD] Family 10h [Opteron, Athlon64, Sempron] Link Control 01:05.0 VGA compatible controller: ATI Technologies Inc Radeon HD 3200 Graphics 01:05.1 Audio device: ATI Technologies Inc RS780 Azalia controller

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Defaults of CentOS Install not working with SELinux
by Dan Roberts 30 Apr '09

30 Apr '09

Following a hard drive corruption I have reinstalled the latest version of CentOS and all current patch files. For most applications I selected the default options. By doing this I expected that the packages would play nice with one another and I could customize as necessary. Setting SELinux to enforce I encountered all sorts of problems - but most were resolvable, save for Dovecot, Procmail (for spamc), and an odd one with Apache. Given that these were all installed with the CentOS install defaults, I can't believe I am the only one with these issues but finding a solution has not been self evident. Hoping someone here can help. For Dovecot I get the following: SELinux is preventing dovecot (dovecot_t) "create" to <Unknown> (dovecot_t). For complete SELinux messages. run sealert -l e1b070ab-586a-4c5a-befe-b6a46b9ab992 For procmail I get the following: SELinux is preventing procmail (procmail_t) "execute" to ./spamc (spamc_exec_t). For complete SELinux messages. run sealert -l 0a554689-4948-4edf-9964-dddbfe6a2492 SELinux is preventing sh (procmail_t) "read" to ./spamc (spamc_exec_t). For complete SELinux messages. run sealert -l 1f1ebd83-412d-4e93-a36f-6f3d34c663df For Apache it's even more strange - When started I get: Syntax error on line 283 of /etc/httpd/conf/httpd.conf DocumentRoot must be directory But it is a directory, has the correct permissions and I have even run chcon -R -h -t httpd_sys_content_t /web/www/ in an effort to correct the problem. I run a virtual server too, and in trying to find a fix for this that may be a problem - but first things first. All the other issues I had I could resolve when I ran the specified "sealert" tag and followed the suggested instructions - but those above don't budge. When I go to the fedora.redhat.com/docs/selinux-fq- fc5 site to take on making a local policy module I am quickly getting lost . The option to simply disable SElinux with respect to Apache, Dovecote or anything else is suggested - but not something I see in the GUI window, and I have not figured out how to do it from the command line. Again, because these are default packages, I hope that someone else knows how to resolve these. With respect to the to reports from SELinux regarding Dovecot and promail, here is a bit more info: The info and Raw Audit message for dovecot_t is: Source Context system_u:system_r:dovecot_t:s0 Target Context system_u:system_r:dovecot_t:s0 Target Objects None [ socket ] Source dovecot Source Path /usr/sbin/dovecot Port <Unknown> Host trailrunner Source RPM Packages dovecot-1.0.7-7.el5 Target RPM Packages Policy RPM selinux-policy-2.4.6-203.el5 Selinux Enabled True Policy Type targeted MLS Enabled True Enforcing Mode Enforcing Plugin Name catchall Host Name trailrunner Platform Linux trailrunner 2.6.18-128.1.6.el5xen #1 SMP Wed Apr 1 10:38:05 EDT 2009 i686 athlon Alert Count 2 First Seen Wed Apr 29 15:39:51 2009 Last Seen Wed Apr 29 15:47:31 2009 Local ID e1b070ab-586a-4c5a-befe-b6a46b9ab992 Line Numbers Raw Audit Messages host=trailrunner type=AVC msg=audit(1241041651.976:33): avc: denied { create } for pid=3884 comm="dovecot" scontext=system_u:system_r:dovecot_t:s0 tcontext=system_u:system_r:dovecot_t:s0 tclass=socket host=trailrunner type=SYSCALL msg=audit(1241041651.976:33): arch=40000003 syscall=102 success=no exit=-13 a0=1 a1=bf851070 a2=9e45030 a3=3e1 items=0 ppid=3883 pid=3884 auid=4294967295 uid=0 gid=0 euid=0 suid=0 fsuid=0 egid=0 sgid=0 fsgid=0 tty=(none) ses=4294967295 comm="dovecot" exe="/usr/sbin/dovecot" subj=system_u:system_r:dovecot_t:s0 key=(null) The Raw Audit Message for Procmail is: Source Context system_u:system_r:procmail_t:s0 Target Context system_u:object_r:spamc_exec_t:s0 Target Objects ./spamc [ file ] Source procmail Source Path /usr/bin/procmail Port <Unknown> Host trailrunner Source RPM Packages procmail-3.22-17.1.el5.centos Target RPM Packages Policy RPM selinux-policy-2.4.6-203.el5 Selinux Enabled True Policy Type targeted MLS Enabled True Enforcing Mode Enforcing Plugin Name catchall_file Host Name trailrunner Platform Linux trailrunner 2.6.18-128.1.6.el5xen #1 SMP Wed Apr 1 10:38:05 EDT 2009 i686 athlon Alert Count 29 First Seen Wed Apr 29 15:40:40 2009 Last Seen Wed Apr 29 16:25:40 2009 Local ID 0a554689-4948-4edf-9964-dddbfe6a2492 Line Numbers Raw Audit Messages host=trailrunner type=AVC msg=audit(1241043940.918:166): avc: denied { execute } for pid=3344 comm="procmail" name="spamc" dev=dm-0 ino=18762675 scontext=system_u:system_r:procmail_t:s0 tcontext=system_u:object_r:spamc_exec_t:s0 tclass=file host=trailrunner type=SYSCALL msg=audit(1241043940.918:166): arch=40000003 syscall=11 success=no exit=-13 a0=8ef1d90 a1=8ef1020 a2=8ef32d8 a3=1 items=0 ppid=3343 pid=3344 auid=4294967295 uid=0 gid=12 euid=0 suid=0 fsuid=0 egid=12 sgid=12 fsgid=12 tty=(none) ses=4294967295 comm="procmail" exe="/usr/bin/procmail" subj=system_u:system_r:procmail_t:s0 key=(null)

4 7

ps error
by P.A 30 Apr '09

30 Apr '09

Hi does anyone know what the problem here is [root@dnstest lib]# ps ps: error while loading shared libraries: libproc-3.2.3.so: cannot open shared object file: No such file or directory [root@dnstest lib]# ln -s libproc-3.2.7.so libproc-3.2.3.so [root@dnstest lib]# ps ps: /lib/libproc-3.2.3.so: version `_3_1_14' not found (required by ps) as far as I know only ps is giving me this error. CentOS release 5.3 (Final)

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Discuss April 2009