====== 2016-05-04 - sys SW snapshot ======

modern [[wp>radeon]] GP/GPUs are really good in terms of both performance and price/performance. unfortunately [[wp>AMD]] constantly fails to provide up-to-date [[wp>Fglrx#Linux|fglrx driver]]. even though [[wp>Free_and_open-source_graphics_device_driver#.2Fdrivers.2Fgpu.2Fdrm.2Famd.2Famdgpu|this will most likely change with amdgpu]] driver, as it goes highly open-source... my card is not that new, so i won't get support from there either. no luck this time either.

the problem is that when [[wp>X11]] ABI changes, fglrx usually lags behind for a few months, before compatible binary gets released. until then quite a few updates got blocked.

there is one more problem -- human factor. i update my system very often. since i need to **remember**, that proper driver is not there and i should not install X11 updates until new driver is provided, it's just a matter of time until i make a mistake and have hours-long fun of restoring all necessary packages (and their dependencies!) back to "compatible" version, so that my video driver is happy again. after doing this twice i decided to automate this a little, with two little shell scripts:
  * {{:blog:2016:05:04:make_sys_snapshot.gz|make_sys_snapshot}} -- writes down list of currently installed packages and their versions
  * {{:blog:2016:05:04:restore_sys_snapshot.gz|restore_sys_snapshot}} -- script for doing the actual magic. :)
once system gets accidentally updated, all i need to do is to call the "restore" script and provide it with a date/time of a snapshot to restore to.

there are two "buts" to make this work:
  * run "snapshot" script along with an update (another script in my case -- so no problem here)
  * make sure not to remove apt-get archives (this could be improved, by just downloading needed packages, when missing)

scripts are not high quality, but they seem to do the work for now.