Kategoriarkiv: Nørderi

Computer-nørderi på systemadministrator-niveau.

Ny-ferniseret

Jeg har installeret Varnish Cache foran min web-server. Årsagen skal søges i, at min webserver igennem nogen tid har været lettere ustabil, omend mindre på det seneste. Tilsyneladende får visse web-forespørgsler den til at lave så mange forbindelser til den bagvedliggende sql-service, at serveren først løber tør for ram og kort efter også tør for swap-disk. Så bliver alting meget langsomt … Før eller siden vågner den op igen, simpelthen fordi sql-servicen, eller en af de andre services på serveren, dør og dermed frigiver noget hukommelse.

Jeg håber Varnish er bedre til at håndtere forbindelser fra botter, som øjensynligt er det, der lægger serveren ned.

Fra de gode gamle USENET-dage …

Dear Emily:
How can I choose what groups to post in?
— Confused

Dear Confused:
Pick as many as you can, so that you get the widest audience.  After
all, the net exists to give you an audience.  Ignore those who suggest you
should only use groups where you think the article is highly appropriate.
Pick all groups where anybody might even be slightly interested.
Always make sure followups go to all the groups.  In the rare event
that you post a followup which contains something original, make sure you
expand the list of groups.  Never include a “Followup-to:” line in the
header, since some people might miss part of the valuable discussion in
the fringe groups.
— Emily Postnews Answers Your Questions on Netiquette

Årets energiregnskab – 2012

Brændstof-regnskab:

  • 1085,03 liter diesel (1013,48 liter i 2011)
  • 11518,43 kroner (10226,78 kroner i 2011)
  • 15774 kilometer (15384 kilometer i 2011)
  • gennemsnit: 10,62 kroner per liter og 14,54 kilometer per liter (10,09 kroner per liter og 15,2 kilometer per liter i 2011)

Bilen har haft et dårligt år. I januar 2012 fik den en periodisk fejl, hvor den ikke ville starte. Nogen gange ville den alligevel, når man havde ventet 5 minutter, andre gange måtte den omkring Peugeot. Peugeot kunne ikke finde den eksakte fejl og det endte med mange tusinde kroner i værkstedsregninger, samt en udskiftning af brændstoffilter, lavtryks-brændstofpumpe og sluttelig højtryks-brændstofpumpen. Siden højtryks-brændstofpumpen blev skiftet, i starten af december, har jeg været forskånet for problemer, men først når der er gået ½ år eller mere, begynder min tillid til bilen at vende tilbage 👿

El-forbrug:

  • 6275 kWh (6393 kWh i 2011)
  • uge-gennemsnit: 120 kWh

Et ganske lille fald i forhold til sidste år – men første gang i mange år, at el-forbruget er faldet 🙂


Vand-forbrug:

  • 153,6 m3 (155,6 m3 i 2011)
  • uge-gennemsnit: 3,0 m3


Naturgas-forbrug:

  • 1926,86 m3 (1818,11 m3 i 2011)
  • uge-gennemsnit: 37,05 m3

Ganske lidt højere end 2011.

Årets energiregnskab – 2011

Årets energiregnskab – 2010

Årets energiregnskab – 2009

Årets energiregnskab – 2008

Upgrading Dell PowerEdge servers

Most Dell owners will be familiar with finding the Service Tag of a server, laptop or desktop, then to enter it at the Dell driver download page and be rewarded with a wealth of suggested patches and updates. Unfortunately, there will often be drivers and upgrades far beyond what is needed for exactly your server/laptop/desktop. And to add to the misery, unless you happen to use exactly the Windows version that Dell assume, you will probably have a difficult time, trying to get the upgrades installed.

For Dell servers however, there are some hope for the exhausted sysadm….

Recently I have had the privilege of upgrading two Dell PowerEdge servers, a 2970 and a 2900 respectively. The 2970 was running VMware ESX 4.1 and thus I managed to install the appropriate upgrades, using the CLI in ESX. Except that not all firmware upgrades were available in ESX (Linux) installers and had to be installed from a DOS boot cd.

In the end, I am not even sure, that I had everything upgraded 👿

The 2900 is running ESXi 5.1 and therefore has no CLI. New approach was needed and preferably something easier. And there is a surprisingly easy method!

  1. Download CentOS Live DVD – find your appropriate mirror site.
  2. Write iso file to a blank dvd
  3. Ensure your server is able to obtain an ip address and is internet connected
  4. Boot the server onto the CentOS
  5. Install Dell firmware update utility – see below

The use of CentOS is due to the Dell preference for Red Hat Enterprise Linux (RHEL), which you may not have at hand. CentOS is pretty compatible and for this purpose fully compatible.

How to install the Dell firmware update utility – in 8 lines or less:

# If proxy is needed, uncomment the next two lines and fill in as appropriate
# declare -x http_proxy="http://proxy:3128"
# declare -x ftp_proxy="http://proxy:3128"
wget -q -O - http://linux.dell.com/repo/hardware/latest/bootstrap.cgi | bash
yum install dell_ft_install
yum install $(bootstrap_firmware)
inventory_firmware
update_firmware --yes

That’s it! The last command 'update_firmware --yes' will detect what firmware updates are needed and install as necessary. Total downtime should be less than 30 minutes, if you have prepared as described above.

Update: Some updates are done, using the internal flash memory as a temporary boot device, e. g. the BIOS firmware update. Therefore the server must be rebooted and not powered off, after an update.

Update II (Sep. 19th 2012): I first performed this on an older PowerEdge 2900. Due to its age, it had only few updates of recent date. I just updated a much newer R610 and found that the Dell repository for the above update procedure, is some what out of date. 👿 So don’t expect to get the newest firmware, if your server is of recent date, but you’re still able to get a very precise inventory of your server from the above procedure and then use that inventory to identify the exact right upgrades for your server and then download them manually from Dell Support.

UPS…

Jun 25 02:24:15 +02:00 xerox apcupsd: [daemon.crit] Power failure.
Jun 25 02:24:16 +02:00 xerox apcupsd: [daemon.alert] User logins prohibited
Jun 25 02:24:22 +02:00 xerox apcupsd: [daemon.crit] Running on UPS batteries.

Jun 25 04:12:31 +02:00 xerox apcupsd: [daemon.crit] Power failure.
Jun 25 04:12:32 +02:00 xerox apcupsd: [daemon.alert] User logins prohibited
Jun 25 04:12:37 +02:00 xerox apcupsd: [daemon.crit] Running on UPS batteries.
Jun 25 04:12:37 +02:00 xerox apcupsd: [daemon.crit] Mains returned. No longer on UPS batteries.
Jun 25 04:12:37 +02:00 xerox apcupsd: [daemon.alert] Power is back. UPS running on mains.
Jun 25 04:12:37 +02:00 xerox apcupsd: [daemon.alert] Allowing logins

– højst et par minutter senere slukkede UPSen helt umotiveret og uvarslet 👿 . Da jeg tændte den igen, ved 7-tiden, viste den overspændingsfejl og USB-porten var død. Ved hjælp af serielporten fik jeg udlæst data fra den – 271 V på forsyningssiden, påstod den. Et voltmeter viste 232 V. Den viste også for høj batterispænding og så tog jeg den altså fra.

Nu må jeg se, om jeg kan få indboforsikringen til at dække den.