USB flash drive for logs - what filesystem to use?

Hi, I want to preserve my logs (system log, majordomo, rrd) during restarts. I have 2 HDD attached through mSATA, but I use them mainly for backups and most of the time they are idle (and I want it to be like that). So my idea was to use spare 2GB USB flash drive, but I don’t know what filesystem would be best for this purpose (to avoid cells wear as much as possible).

  1. What filesystem to use? JFFS2, UBIFS, F2FS, other? [eventually what format parameters to use]?
  2. What happens if my USB stick dies or will not be mounted? Is it problem for Omnia?

Update:
I’ve tried to use F2FS. You have to install f2fs-tools in order to format a drive, but OpenWRT has old 1.4.0 version in repositories which has some bugs as I read (fixed in 1.4.1). So I formatted the drive to f2fs on Linux PC (f2fs-tools 1.6.1). Problem is that f2fs partition UUID is not detected by Omnia as mount point. I’ve ended up with ext2 for now as it seems only extX partitions are detected well :frowning:

I wanted to configure ext4 usb drive to system log. But unsuccessfully when i change destination folder in : System > Loging > Write system log to file: /mnt/SamsungFlash/backup/system.log file system.log is still empty. So i don´t know how it will work.

I think this option is not working at all, because default value there is /tmp/system.log and this not corresponds with reality. System logs are stored in /tmp/log/messages[.x] files.
Majordomo and rrd files are stored to usb drive correctly.