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Most other questions here close to this topic are either for SSDs, or ReadOnly usb live images.

I'd like opinions on Read-Write usb images. I pretty much installed Fedora18 on a 16GB USB3 pen drive (it's faster then a harddrive). i'm currently using ext4 and not giving any though about trim. The only thing i did was to mount all the frequently-written to directories (e.g. /tmp) to tmpfs.

my usage pattern will be to almost never write to the disk, only on system updates. (it's a home theater pc "HTPC" box)

I found publications suggesting JFFS2, YAFFS, UBIFS... but i know very little about them (my only other experience is with RO flash FS, which i use mostly for openWRT) and that paper makes considerations about the type of flash memory being used (i have no clue how to extract that information from my devices or from the manufacturer pages)

So, before I waste days research this topic, should i care about any of those? are them better than ext4 nowadays (that paper is from 2011)? Would i loose any functionality running those file systems as opposed to ext4 (e.g. permission control, suid control, etc)?


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closed as not constructive by MaQleod, ChrisF, BBlake, Diogo, 8088 Dec 21 '12 at 16:31

As it currently stands, this question is not a good fit for our Q&A format. We expect answers to be supported by facts, references, or expertise, but this question will likely solicit debate, arguments, polling, or extended discussion. If you feel that this question can be improved and possibly reopened, visit the help center for guidance.If this question can be reworded to fit the rules in the help center, please edit the question.

Honestly? If you're running your entire OS off of a flashdrive, the filesystem is the last thing you should be worried about. All those filesystems will give you the same features that linux uses, and that's basically true of all filesystems you'll encounter on linux that aren't FAT or NTFS. My feeling is that you're overthinking this. – Arkenklo Dec 20 '12 at 22:09
So i don't need to worry about longevity and those things as well? – gcb Dec 20 '12 at 22:31
Love how closed and not constructive questions keep getting the "popular question" badge – gcb Sep 30 '13 at 21:57
First thing you need is to mount /var/log to ram to that logs don't get written to ram. Or even better use XBMC distro based on OpenWrt which is optimized for flash storage so they are extra careful that nothing is written to disk during normal usage. – valentt May 6 '14 at 17:07
up vote 1 down vote accepted

Making your root filesystem read-only, as in Eric Seppanen's answer, is an excellent suggestion.

For solid state drives and flash drives, journaling may not be a good idea; the drives' faster seek times mean that the performance gain of journaling is less noticeable, and journaling means extra writes which means less disk lifespan. See this Slashdot question and especially these comments for discussion.


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thanks for the link, but it's standard /., the comments only discuss swap which is not even needed if all you have is lots of RAM + one flash drive for storage. And journaling is mostly about data integrity, not performance (actually hammer performance in all cases, unless you compare it to other forms of data integrity). i now stopped to work on other aspects of the hardware, but i will probably go back and experiment with XFS, nils and brtfs... my guess is that the one that does less good use of the space will be better.. i.e. the lazier with cleaning up will be less impacted by flash memory – gcb Dec 26 '12 at 19:32

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