Alexander Leidinger

Just another weblog


Gain­ing space on Android after ART->Dalvik switch (root access required)

I (still) use a Nexus S phone. I am using Cyanogen­mod on it. After an arti­cle in a com­puter mag­a­zine I decided to give the ART-runtime a try instead of the default Dalvic-runtime. Unfor­tu­nately I do not have enough free space free (and all what I can is moved to the USB stor­age already) to really use the ART-runtime.

After switch­ing back to the Dalvic-runtime, I had only 2/3 of the pre­vi­ously avail­able space free. After a lit­tle bit of look­ing around I found /data/dalvik-cache. I deleted with a file man­ager the con­tent of the direc­tory (you will get some “app crashed/died” mes­sages) and rebooted the phone (this is not the same as for­mat­ting the cache par­ti­tion in the recov­ery system).

Dur­ing boot it pop­u­lated the direc­tory again and now I have more than 4/3 of free space on the inter­nal storage.

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New users in Solaris 10 branded zones on Solaris 11 not han­dled automatically

A col­league noticed that on a Solaris 11 sys­tem a Solaris 10 branded zone “gains” two new dae­mons which are run­ning with UID 16 and 17. Those users are not auto­mat­i­cally added to /etc/passwd, /etc/shadow (and /etc/group)… at least not when the zones are imported from an exist­ing Solaris 10 zone.

I added the two users (netadm, netcfg) and the group (netadm) to the Solaris 10 branded zones by hand (copy&paste of the lines in /etc/passwd, /etc/shadow, /etc/group + run pwconv) for our few Solaris 10 branded zones on Solaris 11.

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Increase of DNS requests after a crit­i­cal patch update of Solaris 10

Some weeks ago we installed crit­i­cal patch updates (CPU) on a Solaris 10 sys­tem (inter­nal sys­tem, a year of CPU to install, noth­ing in it affect­ing us or was con­sid­ered a secu­rity risk, we decided to apply this one regard­less to not fall behind too much). After­wards we noticed that two zones are doing a lot of DNS requests. We noticed this already before the zones went into pro­duc­tion and we con­fig­ured a pos­i­tive time to live in nscd.conf for “hosts”. Addi­tion­ally we noticed a lot of DNS requests for IPv6 addresses (AAAA lookups), while absolutely no IPv6 address is con­fig­ured in the zones (not even for local­host… and those are exclu­sive IP zones). Appar­ently with one of the patches in the CPU the behav­iour changed regard­ing the caching, I am not sure if we had the AAAA lookups before.

Today I got some time to debug this. After adding caching of “ipn­odes” in addi­tion to “hosts” (and I con­fig­ured a neg­a­tive time to live for both at the same time), the DNS requests came down to a sane amount.

For the AAAA lookups I have not found a solu­tion. By my read­ing of the doc­u­men­ta­tion I would assume there are not IPv6 DNS lookups if there is not IPv6 address configured.

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Updat­ing FreeBSD 8.2 (or 9.x) to 10 (beta4)

This is a lit­tle descrip­tion how I remotely (no con­sole, booted into multi-user dur­ing update, no exter­nal ser­vices like jails/httpd/… run­ning) updated a FreeBSD 8.2 to 10 (beta4) from source. This should also work when updat­ing from FreeBSD 9.x. Note, I had already switched to ATA_CAM on 8.2, so not instruc­tions for the name change of the ata devices. No IPv6, WLAN or CARP is in use here, so changes which are needed in this area are not cov­ered. Read UPDATING care­fully, there are a lot of changes between major releases.

What I did:

  • update /usr/src
  • make build­world
  • replace “make ” in /usr/src/Makefile.inc1 with ${MAKE} (two times, one for “VERSION”, one for “BRANCH”)
  • ver­ify ker­nel con­fig for changes needed (run­ning “con­fig MyK­er­nel” in /usr/src/sys/YourArch/conf/ helps to iden­tify syn­tax prob­lems), sorry I didn’t take notes, but I diffed the old and the new GENERIC con­fig and added/removed accord­ing to my interests
  • /usr/obj/…/src/usr.bin/bmake/make build­ker­nel KERNCONF=MyKernel
  • /usr/obj/…/src/usr.bin/bmake/make instal­lk­er­nel KERNCONF=MyKernel KODIR=/boot/kernel.10
  • merge­mas­ter –p
  • /usr/obj/…/src/usr.bin/bmake/make install­world DESTDIR=/somewhere/test
  • mkdir /root/net10; cp /somewhere/test/rescue/ifconfig /somewhere/test/rescue/route /root/net10
  • cre­ate the file /etc/rc.10update with:
    case $(uname –r) in
    export MYIFCONFIG
    export MYROUTE
  • change the files (stu­pid approach: grep for “ifcon­fig” and “route” in /etc/rc.d to iden­tify files which need to change, I skipped files which I iden­ti­fied as not needed in my case, if you use pf/IPv6/bridge/…, you may have to change some more files) /etc/rc.d/auto_linklocal /etc/rc.d/defaultroute /etc/rc.d/netif /etc/rc.d/netwait /etc/rc.d/routing: add “. /etc/rc.10update” at the end of the block with “. /etc/rc.subr”, change the “ifconfig”-command to ${MYIFCONFIG}, change the “route”-command to ${MYROUTE}
  • change /etc/net­work.subr: add “. /etc/rc.10update” before the first func­tion, change the “ifconfig”-command to ${MYIFCONFIG}, change the “route”-command to ${MYROUTE}
  • make sure that the changes you made are 100% cor­rect, rather triple-check than to not check at all (you will be locked out if they are not 100% OK)
  • stop any jails and make sure they do not restart at boot
  • deac­ti­vate the gmir­ror of the root-fs, if there is one (it is maybe eas­ier to ask a remote hand to swap the boot order in case of problems)
  • here you could just a reboot of the server to come back to your cur­rent OS ver­sion, so make sure that the mod­i­fi­ca­tions in /etc did not cause any prob­lems with the old ver­sion (in case you see prob­lems with the v10 ker­nel), but if you do not have a remote con­sole to single-user mode you have no chance to directly fix the prob­lem (risk mit­i­ga­tion described above), no mat­ter which ver­sion of the ker­nel you boot
  • next­boot –k kernel.10
  • shut­down –r now
  • login
  • check dmesg
  • optional: mv /boot/kernel /boot/kernel.8
  • make instal­lk­er­nel KERNCONF=MyKernel
    to have a v10 /boot/kernel
  • make install­world
  • merge­mas­ter
  • make delete-old
  • rm –r /etc/rc.10update /root/net10
  • change rc.conf: add “inet” in ifconfig-aliases
  • review sysctl.conf for out­dated entries
  • shut­down –r now
  • optional: rm –r /boot/kernel.10
  • enable jails again (or later… updat­ing jails is not described here)
  • activate/resync mirror(s)
  • rebuild all ports (atten­tion: new pkg system)
  • make delete-old-libs
  • reboot again to make sure every­thing is OK after the port-rebuild and removal of old libs (a console.log (syslog.conf) helps here
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Lin­ux­u­la­tor explained: How to cre­ate Linux bina­ries on FreeBSD

There may by cases where you want to gen­er­ate a Linux binary on a FreeBSD machine. This is not a prob­lem with the lin­ux­u­la­tor, but not with the default linux_base port.

As you may know, the linux_base port is designed to deliver an inte­grated expe­ri­ence with FreeBSD native pro­grams. As such some parts of the native FreeBSD infra­struc­ture is used. If you would try to use a Linux–com­piler to gen­er­ate Linux–bina­ries, you would run into the prob­lem that by default the FreeBSD includes are used.


To have a fully fea­tured and non-integrated Linux envi­ron­ment on your FreeBSD sys­tem either mount an exist­ing (and com­pat­i­ble) Linux instal­la­tion some­where into your FreeBSD sys­tem, or install a linux_dist port. This can be done addi­tion­ally to an already installed linux_base port.


When you have a com­plete Linux envi­ron­ment avail­able, you need to mount the FreeBSD devfs to /path/to/complete_linux/dev, lin­procfs to /path/to/complete_linux/proc and lin­sysfs to /path/to/complete_linux/sys to have a com­plete setup.

Use it

Now you just need to chroot into this  /path/to/complete_linux and you configure/make/install or what­ever you need to do to gen­er­ate your desired Linux binary.

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