Archive for October 19th, 2012

19 October – Saint John of Rila (The Greatest venerated Bulgarian saint) Dormition feast day

Friday, October 19th, 2012

Saint John of Rila The Greatest Veneration Bulgarian saint Hermit of all times feast day in Bulgarian Orthodox Church 19 of October

Today I’m joyed to note here in our Bulgarian Orthodox Church calendar we venerate the Greatest Bulgarian saint and maybe one of the greatest Hesychast (Hermits) of our times – Saint John of Rila

The spiritual ancestry of this great saint does enrich the Orthodox Churches around the world even to this very day. St. John of Rila is considered the forefather of Hermit Life in Bulgaria and officially heavenly protector of Bulgaria and our Bulgarian Orthodox Church

Great are the mercies over the years, we as Bulgarians received throgh the holy prayers of st. John.
The saint is called of Rila because he spend biggest part of his life in Rila Mountain “desert”, living a life of solitude and holiness. As his living states, he has numerous times been fighting the passions and been fighted by the devil and evil spirits, who tried to shutter his faith unsucessfully. With his vigilance and persistance in faith and his deep love for Christ, he achieved saintship.
Pupils of the saint has later established Rila Monastery – a monastery holding rich spirituality and being a spiritual fortress of Orthodox Christian faith. St. John is also considered a building stone (not to say creator) of Bulgarian lands monastic life. Here is the Troparion to the Saint:


Тропар на Св. Иван Рилски / St John of Rila’s antiphon

For his holy living our Lord Jesus Christ granted the Saint, great spiritual gifts including the gift of miracle making and healing.

The most famous story the meeting of Saint John with King Peter I is well known and documented in historical sources, Here is the story itself (Story is copied as translated from Bulgarian to English and located in wikipedia free encyclopedia:

Tsar Peter I (son of tsar Simeon I) took a 120 km. trip to the Rila Mountains in order to meet St. Ivan and seek spiritual advice. Their meeting is described in detail in one the hagiologies of St. Ivan Rilski as well as in the Testament of St. Ivan of Rila itself. After a long and exhausting trip, tsar Peter I reached the place where St. Ivan Rilski lived, however, upon arrival, the tsar then realized that the dwelling of the saint was inaccessible, probably due to the rough local terrain. As the medieval hagiologies point out, St. Ivan of Rila refused to meet the tsar in person to avoid the temptation of vanity and pride due to the extraordinary visit. As such, the two men only bowed to each other from a distance. The emperor sent a soldier to deliver the gifts that were brought for the saint. St Ivan of Rila kept only the a small portion of food and returned all of the gold and precious gifts, advising the tsar that monarchs need gold in order to protect the country and help the poor.

According to local Bulgarian Church Tradition, due to his saintship God granted the saint Dormition. Dormition is less used (word) term outside of Orthodox Christian faith, in short it means Jesus himself went down from Heaven with with Holy Theotokos and his Holy Angels to receive St. John of Rila’s saintly soul!

Those familiar with Orthodox Christian faith base, would know over the whole humanity history, there are few respected to receive Dormition. Most famous and greatest Dormition is of course, the Dormition of Holy Theotokos; According to our Church history in a similar way to Holy Theotokos Dormition, saint John received his Glorofication and Salvation on the day of his Dormition.

Shortly before his death (Aug 18, 946) St. Ivan of Rila wrote his Testament Zavet (the bulgarian word for testament). st. John’s Testament is a literary work and a a deeply spiritual Christian message instructing his successors how to adjoin to proper a high spiritual life. The testament is an instruction dedicated to teach the whole Bulgarian nation to stick firmly to faith in Christ and live a good life in Christ.

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Posted in Christianity | No Comments »

Disabling sound kernel modules on Debian and Ubuntu GNU / Linux servers

Friday, October 19th, 2012

First step is to list modules related to sound (snd):


root@pcfreak:/var/www# lsmod|grep -i snd
snd_hda_codec_realtek 235234 1
snd_hda_intel 20035 0
snd_hda_codec 53940 2 snd_hda_codec_realtek,snd_hda_intel
snd_hwdep 5220 1 snd_hda_codec
snd_pcm_oss 32415 0
snd_mixer_oss 12478 1 snd_pcm_oss
snd_pcm 60151 3 snd_hda_intel,snd_hda_codec,snd_pcm_oss
snd_seq_midi 4256 0
snd_rawmidi 15323 1 snd_seq_midi
snd_seq_midi_event 4628 1 snd_seq_midi
snd_seq 41281 2 snd_seq_midi,snd_seq_midi_event
snd_timer 15502 2 snd_pcm,snd_seq
snd_seq_device 4493 3 snd_seq_midi,snd_rawmidi,snd_seq
snd 45998 11
snd_hda_codec_realtek,snd_hda_intel,snd_hda_codec,snd_hwdep,snd_pcm_oss,snd_mixer_oss,snd_pcm,snd_rawmidi,snd_seq,snd_timer,snd_seq_device
soundcore 4566 1 snd
snd_page_alloc 6217 2 snd_hda_intel,snd_pcm

Then snd modules could be removed from current live system, for my Intel RealTek SoundBlaster, I had to remove following modules in (remove) order as follows:


root@pcfreak:/var/www# rmmod soundcore
ERROR: Module soundcore is in use by snd
root@pcfreak:/var/www# rmmod snd_hda_codec_realtec
ERROR: Module snd_hda_codec_realtec does not exist in /proc/modules
root@pcfreak:/var/www# rmmod snd_hda_intel
root@pcfreak:/var/www# rmmod snd_hda_codec
ERROR: Module snd_hda_codec is in use by snd_hda_codec_realtek
root@pcfreak:/var/www# rmmod snd_hda_codec_realtek
root@pcfreak:/var/www# rmmod snd_hda_codec
root@pcfreak:/var/www# rmmod snd_pcm_oss
root@pcfreak:/var/www# rmmod snd_seq_midi
root@pcfreak:/var/www# rmmod snd_rawmidi
root@pcfreak:/var/www# rmmod snd_seq_midi_event
root@pcfreak:/var/www# rmmod snd_seq
root@pcfreak:/var/www# rmmod snd_timer
ERROR: Module snd_timer is in use by snd_pcm
root@pcfreak:/var/www# rmmod snd_seq_device
root@pcfreak:/var/www# rmmod snd_pcm
root@pcfreak:/var/www# rmmod snd_seq_device
ERROR: Module snd_seq_device does not exist in /proc/modules
root@pcfreak:/var/www# rmmod snd_hda_intel
ERROR: Module snd_hda_intel does not exist in /proc/modules
rmmod snd_hwdep
root@pcfreak:/var/www# rmmod snd_mixer_oss
root@pcfreak:/var/www# rmmod snd_timer
root@pcfreak:/var/www# rmmod snd
root@pcfreak:/var/www# rmmod soundcore
root@pcfreak:/var/www#

Next step is to permanently disable all (blacklist) on system boot time loaded kernel modules, to do so in file /etc/modprobe.d/snd-bkaclist.conf, put:


blacklist soundcore
blacklist snd
blacklist snd_pcm
blacklist snd_pcsp
blacklist pcspkr

You can do it from shell ‘echo’-ing into file, like so:

# touch /etc/modprobe.d/snd-blacklist.conf
# cd /etc/modprobe.d/
# echo ‘blacklist soundcore’ >> snd-blacklist.conf
# echo ‘blacklist snd’ >> snd-blacklist.conf
# echo ‘blacklist snd_pcm’ >> snd-blacklist.conf
# echo ‘blacklist snd_pcsp’ >> snd-blacklist.conf
# echo ‘blacklist pcspkr’ >> snd-blacklist.conf

Another way is to use a tiny shellscript containing all previously shown rmmod commands and set the script to be executed via /etc/rc.local by adding the rmmod modules script, before exit 0 rc.local line.

Shell script removing my Realtek ICH sound driversis here
If you like to use it download it in /usr/local/bin or somewhere and invoke it via rc.local.
Removing sound blaster kernel support does not impact the overall machine performance, but in terms of security. Having sound driver modules constantly loaded in memory is a point which a possible attacker can use to root the host, so in my view always sound driver support should be removed.
Well that’s it hope this post helps someone 🙂

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Posted in Linux, Linux Audio & Video, System Administration | 2 Comments »

Fixing strange Debian Linux Squeeze system overloads and Apache Webserver crashes

Friday, October 19th, 2012

For quite some time, my home run server pre-installed with Debian Squeeze Linux has been crashing in a very strange circumstances inside dmesg kernel log and in /var/log/messages on times, when this crashes occur I see errors / warnings spitting not very helpful kernel debug messages like this:


Oct 16 11:32:28 pcfreak kernel: [66657.797930] Pid: 0, comm: swapper Not tainted 2.6.32-5-amd64 #1
Oct 16 11:32:28 pcfreak kernel: [66657.797931] Call Trace:
Oct 16 11:32:28 pcfreak kernel: [66657.797933] [] ? select_nohz_load_balancer+0x94/0x163
Oct 16 11:32:28 pcfreak kernel: [66657.797943] [] ? __report_bad_irq+0x30/0x7d
Oct 16 11:32:28 pcfreak kernel: [66657.797945] [] ? note_interrupt+0x105/0x16e
Oct 16 11:32:28 pcfreak kernel: [66657.797948] [] ? handle_fasteoi_irq+0x93/0xb5
Oct 16 11:32:28 pcfreak kernel: [66657.797952] [] ? handle_irq+0x17/0x1d
Oct 16 11:32:28 pcfreak kernel: [66657.797954] [] ? do_IRQ+0x57/0xb6
Oct 16 11:32:28 pcfreak kernel: [66657.797956] [] ? ret_from_intr+0x0/0x11
Oct 16 11:32:28 pcfreak kernel: [66657.797957] [] ? poll_idle+0x28/0x5b
Oct 16 11:32:28 pcfreak kernel: [66657.797963] [] ? poll_idle+0xa/0x5b
Oct 16 11:32:28 pcfreak kernel: [66657.797965] [] ? cpuidle_idle_call+0x94/0xee
Oct 16 11:32:28 pcfreak kernel: [66657.797968] [] ? cpu_idle+0xa2/0xda
Oct 16 11:32:28 pcfreak kernel: [66657.797971] [] ? early_idt_handler+0x0/0x71
Oct 16 11:32:28 pcfreak kernel: [66657.797974] [] ? start_kernel+0x3dc/0x3e8
Oct 16 11:32:28 pcfreak kernel: [66657.797976] [] ?x86_64_start_kernel+0xf9/0x106

and this:


Oct 16 15:53:14 pcfreak kernel: [82297.972509] apache2 invoked oom-killer: gfp_mask=0x200da, order=0, oom_adj=0
Oct 16 15:53:30 pcfreak kernel: [82297.972513] apache2 cpuset=/ mems_allowed=0
Oct 16 15:53:30 pcfreak kernel: [82297.972515] Pid: 8943, comm: apache2 Not tainted 2.6.32-5-amd64 #1
Oct 16 15:53:30 pcfreak kernel: [82297.972517] Call Trace:
Oct 16 15:53:30 pcfreak kernel: [82297.972523] [] ? oom_kill_process+0x7f/0x23f
Oct 16 15:53:30 pcfreak kernel: [82297.972527] [] ? timekeeping_get_ns+0xe/0x2e
Oct 16 15:53:30 pcfreak kernel: [82297.972529] [] ? __out_of_memory+0x12a/0x141
Oct 16 15:53:30 pcfreak kernel: [82297.972531] [] ? out_of_memory+0x140/0x172
Oct 16 15:53:30 pcfreak kernel: [82297.972534] [] ? __alloc_pages_nodemask+0x4ec/0x5fb
Oct 16 15:53:30 pcfreak kernel: [82297.972538] [] ? do_wp_page+0x386/0x707
Oct 16 15:53:30 pcfreak kernel: [82297.972541] [] ? autoremove_wake_function+0x9/0x2e
Oct 16 15:53:30 pcfreak kernel: [82297.972544] [] ? __wake_up_common+0x44/0x72
Oct 16 15:53:30 pcfreak kernel: [82297.972547] [] ? __wake_up+0x30/0x44
Oct 16 15:53:30 pcfreak kernel: [82297.972549] [] ? handle_mm_fault+0x704/0x80f
Oct 16 15:53:30 pcfreak kernel: [82297.972553] [] ? do_page_fault+0x2e0/0x2fc
Oct 16 15:53:30 pcfreak kernel: [82297.972556] [] ? page_fault+0x25/0x30


Oct 16 18:41:55 pcfreak kernel: [ 6582.554746] Mem-Info:
Oct 16 18:41:55 pcfreak kernel: [ 6582.554747] Node 0 DMA per-cpu:
Oct 16 18:41:55 pcfreak kernel: [ 6582.554751] CPU 0: hi: 0, btch: 1 usd: 0
Oct 16 18:41:55 pcfreak kernel: [ 6582.554753] CPU 1: hi: 0, btch: 1 usd: 0
Oct 16 18:41:55 pcfreak kernel: [ 6582.554755] Node 0 DMA32 per-cpu:
Oct 16 18:41:55 pcfreak kernel: [ 6582.554758] CPU 0: hi: 186, btch: 31 usd: 0
Oct 16 18:41:55 pcfreak kernel: [ 6582.554760] CPU 1: hi: 186, btch: 31 usd: 0
Oct 16 18:41:55 pcfreak kernel: [ 6582.554762] Node 0 Normal per-cpu:
Oct 16 18:41:55 pcfreak kernel: [ 6582.554765] CPU 0: hi: 186, btch: 31 usd: 5
Oct 16 18:41:55 pcfreak kernel: [ 6582.554767] CPU 1: hi: 186, btch: 31 usd: 0
Oct 16 18:41:55 pcfreak kernel: [ 6582.554773] active_anon:1580557 inactive_anon:308231 isolated_anon:9504
Oct 16 18:41:55 pcfreak kernel: [ 6582.554775] active_file:148 inactive_file:220 isolated_file:32
Oct 16 18:41:55 pcfreak kernel: [ 6582.554776] unevictable:0 dirty:5 writeback:494 unstable:0
Oct 16 18:41:55 pcfreak kernel: [ 6582.554777] free:12063 slab_reclaimable:4262 slab_unreclaimable:17553
Oct 16 18:41:55 pcfreak kernel: [ 6582.554778] mapped:148 shmem:43 pagetables:89423 bounce:0
Oct 16 18:41:55 pcfreak kernel: [ 6582.554781] Node 0 DMA free:15880kB min:20kB low:24kB high:28kB active_anon:0kB inactive_anon:0kB active_file:0kB inactive
_file:0kB unevictable:0kB isolated(anon):0kB isolated(file):0kB present:15328kB mlocked:0kB dirty:0kB writeback:0kB mapped:0kB shmem:0kB slab_reclaimable:0kB
slab_unreclaimable:8kB kernel_stack:0kB pagetables:0kB unstable:0kB bounce:0kB writeback_tmp:0kB pages_scanned:0 all_unreclaimable? no
Oct 16 18:41:55 pcfreak kernel: [ 6582.554794] lowmem_reserve[]: 0 2947 7995 7995
Oct 16 18:41:55 pcfreak kernel: [ 6582.554798] Node 0 DMA32 free:24672kB min:4212kB low:5264kB high:6316kB active_anon:2153732kB inactive_anon:538456kB activ
e_file:32kB inactive_file:56kB unevictable:0kB isolated(anon):6912kB isolated(file):0kB present:3017744kB mlocked:0kB dirty:16kB writeback:336kB mapped:184kB
shmem:168kB slab_reclaimable:4400kB slab_unreclaimable:21908kB kernel_stack:1816kB pagetables:131140kB unstable:0kB bounce:0kB writeback_tmp:0kB pages_scann
ed:42 all_unreclaimable? no
Oct 16 18:41:55 pcfreak kernel: [ 6582.554812] lowmem_reserve[]: 0 0 5048 5048
Oct 16 18:41:55 pcfreak kernel: [ 6582.554815] Node 0 Normal free:7700kB min:7216kB low:9020kB high:10824kB active_anon:4168496kB inactive_anon:694468kB acti
ve_file:560kB inactive_file:824kB unevictable:0kB isolated(anon):31104kB isolated(file):128kB present:5169180kB mlocked:0kB dirty:4kB writeback:1640kB mapped
:408kB shmem:4kB slab_reclaimable:12648kB slab_unreclaimable:48296kB kernel_stack:3488kB
pagetables:226552kB unstable:0kB bounce:0kB writeback_tmp:0kB pages_
scanned:224 all_unreclaimable? no
Oct 16 18:41:55 pcfreak kernel: [ 6582.554829] lowmem_reserve[]: 0 0 0 0
Oct 16 18:41:55 pcfreak kernel: [ 6582.554832] Node 0 DMA: 2*4kB 2*8kB 3*16kB 4*32kB 3*64kB 3*128kB 1*256kB 1*512kB 2*1024kB 2*2048kB 2*4096kB = 15880kB
Oct 16 18:41:55 pcfreak kernel: [ 6582.554842] Node 0 DMA32: 114*4kB 73*8kB 273*16kB 256*32kB 85*64kB 10*128kB 1*256kB 0*512kB 0*1024kB 0*2048kB 1*4096kB = 2
4672kB
Oct 16 18:41:55 pcfreak kernel: [ 6582.554852] Node 0 Normal: 867*4kB 103*8kB 7*16kB 13*32kB 7*64kB 1*128kB 1*256kB 0*512kB 0*1024kB 1*2048kB 0*4096kB = 7700
kB
Oct 16 18:41:55 pcfreak kernel: [ 6582.554862] 89702 total pagecache pages
Oct 16 18:41:55 pcfreak kernel: [ 6582.554864] 89257 pages in swap cache
Oct 16 18:41:55 pcfreak kernel: [ 6582.554866] Swap cache stats: add 4155760, delete 4066503, find 618278/801429
Oct 16 18:41:55 pcfreak kernel: [ 6582.554868] Free swap = 0kB
Oct 16 18:41:55 pcfreak kernel: [ 6582.554870] Total swap = 5787636kB
Oct 16 18:41:55 pcfreak kernel: [ 6582.581389] 2096640 pages RAM
Oct 16 18:41:55 pcfreak kernel: [ 6582.581392] 60657 pages reserved
Oct 16 18:41:55 pcfreak kernel: [ 6582.581394] 330845 pages shared
Oct 16 18:41:55 pcfreak kernel: [ 6582.581397] 2012293 pages non-shared

It took, me long time of thinking and pondering what is causing this errors ….
I thought it is due to some failing RAM bank or some kind of conflict URL hardware inconpitability, I had some thoghts that it is possible Hard Disk is failing or have some bad blocks; However as I bought the machine brand new and besides that it is not assembled one PC but brand one Lenovo ThinkEdge, I’ve further thought and investigated if Apache is failing due to some problem with Apache modules. After reviewing all system installed modules, I’ve found php5-suhosin, was installed on the system (probably as a dependency package) to something else I previously installed ??
I don’t have a very positive feedback on some other servers I configured with Apache, whether php5-suhosin was installed so decided to try removing it ….:


# dpkg -r php5-suhosin
.....
# dpkg --purge php5-suhosin

I’ve also lowered down a bit the StartServers and MaxSpareServers (mod_prefork_modules) section in /etc/apache2/apache2.conf:

StartServers there was set to: 700 and MaxSpareServers to 150, I’ve changed the values to read as so:



StartServers 500
MinSpareServers 100
MaxSpareServers 120
MaxClients 1000
MaxRequestsPerChild 10000

Just for info machine is with 8 Gigabytes of Memory and has 1x 2 cores CPU:


# free -m |grep -i 'mem:'
Mem: 7953 7871 81 0 91 753


# cat /proc/cpuinfo |grep -i proces -A 5
processor : 0
vendor_id : GenuineIntel
cpu family : 6
model : 42
model name : Intel(R) Pentium(R) CPU G630 @ 2.70GHz
stepping : 7
--
processor : 1
vendor_id : GenuineIntel
cpu family : 6
model : 42
model name : Intel(R) Pentium(R) CPU G630 @ 2.70GHz
stepping : 7

After that to make module already loaded in system memory by Apache main (parent) process, I restarted Apache as well:


# apache2ctl -k restart

Following that changes – Thanks God! ; I no longer experience the weird errors and Server overloads 😉

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Posted in Everyday Life, System Administration, Web and CMS | 1 Comment »