Writing some ideas down while thinking. /!\ Warning: i do not know much about this - these ideas are not researched much...Interesting! Will try compressed btrfs on a stick some time
I guess it need a separate /boot partition in i.e ext4 format, if system root is in compressed btrfs?
BTW myself would also make a ntfs partition so the same stick can also be used to simply plug into a MS system and exchange files.
And in my case, as i would probably carry some of my customers files i need to encrypt , so i would make a LUKS encrypted LVM, and the compressed btrfs in that. Possible also swap partition in that LVM, but see further below.
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To be able to boot many different systems, the install should have many drivers... is there an easy way to include all GPU and wifi etc drivers. Something like task-graphicsdrivers, task-wifidrivers, etc would be handy.
Do the live iso run some hardware detection and configuring that an installed system skips over?
- If so, can it be set on this USB-installed system to run every boot, or maybe by grub menu choice?
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Regarding booting on most systems, can Mageia be installed so it boots like the Live systems; both on UEFI systems that require UEFI, and on machines that only do old style BIOS boot?
-And when updating kernel, both boot methods are updated?
Sounds hard.
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Another idea: enable zswap to eliminate/minimise swap usage to USB, but still use USB swap automatically when - if ever - RAM is not enough. (it is a compressed cache layer on top of the swap device - especially note: the total available swap is not larger than the swap on disk.)
https://en.wikipedia.org/wiki/Zswap https://wiki.archlinux.org/index.php/Zswap It can easily be a separate boot choice in grub, adding kernel parameter zswap.enabled=1, or can be enabled in runtime. Without zswap enabled the system simply use the disk swap space.
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BTW, it would be good if the swap on USB was compressed.
So maybe create the USB swap as a file on the already compressed file system?
BUT! [url}https://btrfs.wiki.kernel.org/index.php/Project_ideas#Swap_file_support] btrfs do not support swap files[/URL]. -> Need some more complicated setup. Loopback, with some compression mojo on a file on my ntfs partition. seems too much work and too much that can break...
So i would maybe put them in my ntfs partition. Uh, if that is compatible?
https://support.rackspace.com/how-to/cr ... swap-file/ https://www.cyberciti.biz/faq/linux-add ... ile-howto/ That also makes it easier to modify the size, than if we use separate partition. If we create several small swap files to begin with, we can delete one at a time if we need more file space for other stuff and the result is immediate without partitioning hassles (but dont forget swapoff and edit fstab...).
Priority could be used to steer kernel to first use /swapfile0, then /swapfile1, etc So i would put them in my ntfs partition. Uh, if that is compatible?
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One stupid thing with this setup is that when zswap is about to move compressed content in RAM to disk, it decompress it first... Normally that is good i think because it most often make read back quick = less delay. In this setup data will be compressed and decompressed... Oh well...
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An alternative is zram, but it use RAM only - a problem when we do not know how much memory the target system have. USBsticks are rather cheap so having extra GB of SWAP i think is normally not a problem. Also, zram can not be so easily configured as a kernel boot choice.
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About what stick to use:
I have noted flash sticks can identify them selves in different ways, and some computers refuse to boot on some sticks. (same iso works on another stick)
Fast, good quality, that support both USB3 and USB2. Large size for storing much, and large also normally mean it is faster to write to, and have better write endurance measured in bytes written.
Mechanically sturdy. Maybe connect using a short extension - less risk of bending connector (been there!) in stick or laptop. (of good quality - i have had glitchy ones...)
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32-bit system - so it can boot on both 32 and 64 bit.
OR, is it possible to have both 32 and 64 bit kernel selectable in grub, or automatically?
Mandriva since 2006, Mageia 2011 at home & work. Thinkpad T40, T43, T400, T510, Dell M4400, M6300, Acer Aspire 7. Workstation using LVM, LUKS, VirtualBox, BOINC