On 20/05/2016 02:24, Daniel Golle wrote: > Hi Karl, > > I thought a bit about fstools since your post because I also had my > difficulties integrating it with applications which require hotplug > storage. I agree with and acknowledge all the points you mentioned. > > In addition I believe that LEDE/OpenWrt generally lacks a high-level > concept to integrate optional block storage. Imho something like /data > on Android (or just mount it to /var?) would be nice and make setting > up services much easier, also without using extroot. Just a missing > convention to agree on. > It could be a symlink to /mnt/sda1 or /mnt/mmcblock0p1 or whatever > is detected first on a specific device. autofs4 with mountd does the > job well imho, I didn't have problems with that. > What's needed are sane defaults depending on the type of hardware > (both, board-type and detected storage peripherals). And a simple > one-click "initialize storage device XYZ and use it per default for all > on this system". That should do partitioning, mkfs and setup fstab. > More complex setups with md raid or even LVM2 and cryptsetup mark the > top-edge of the model. > > I suggest we should draft the structures and api in some etherpad and > then implement an *optional* storage management service based on > fstools and replacing/extending block-mount. Adding hotplug handlers > for block devices should then become rather trivial. > > It'd also be nice to have a "large block storage is now mounted" > runlevel, so services depending on that (think: squid, postgresql, > git server, ...) would be started only once the block device has > settled and was mounted. > > This would allow things like databases or other apps which require > storage to create their filessytem structures automatically in the > package's post-inst-on-target aka. uci-defaults script and have a sane > default set in their configurations. > (I'd very much like to have that e.g. for postgresql, and also offer > some functions in a to-be-created /lib/functions/postgresql.sh for > packages to setup databases) > > If anyone can setup an etherpad in the meantime I'll happily start > adding my suggestings to the spec once I got some sleep... > > > Cheers > > > Daniel >
added a few things here, please add what you think should also be added http://piratepad.net/2le3wZujiS John > > > > On Wed, May 18, 2016 at 04:45:57PM -0000, Karl Palsson wrote: >> >> Listing out a few things I've found with fstools package >> (Version: 2016-05-17-db5d39d48b9d9a77565015c1aafb3ef0d2925f02) >> I'm mostly still working on openwrt CC branch, but the issues >> _seem_ to be fstools related, not kernel related, though I'm >> happy to retest if necessary. Some of these I've discussed on irc >> with blogic and jow, others just here, posting them here for >> posterity as they're bigger than quick fixes on IRC. Further, >> this is largely an area I'm not really comfortable trying to hack >> up patches, they need to follow the style and direction of the >> project more than just my specific needs, so I can't post patches >> for any of these. >> >> * block mount mounts _and_ turns swap on. block umount only unmounts. >> Shouldn't it swapoff as well? >> >> * "block" anything can't have it's output captured. The checks in libubox: >> ulog.c:: ulog_defaults() detect the attempt at capturing the output as a >> !tty and write to syslog instead. >> >> * block doesn't handle hotplug. This is probably the biggest thing. This >> overlaps with the old and unmaintained "mountd" package, which blogic >> expressed interesting destroying/merging/combining with "fstools" This >> doesn't seem to be a problem for usb sticks, because the removal of the >> stick removes the entire device node well. However, an SD card in a slot >> maintains a /dev/sda entry even after the card is removed. "block info" >> will fail to see new block details if a partition was mounted, or as >> activated swap, and swap and mounts are not turned off when the card is >> removed. >> >> I wrote about various trials and tribulations with mountd vs >> block here >> https://lists.openwrt.org/pipermail/openwrt-devel/2016-February/039798.html >> and resolved that I would simply poll "block info" every couple >> of seconds. Unfortunately, that ended up being rather noticeable >> CPU load, so I'm still looking for neat ways of handling sdcards, >> and while mountd noticed disk changes, it failed at reliably >> mounting/unmounting, and most importantly, was and is clearly >> regarded as "not the right way" going forward. >> >> Desktop linux mostly solves this with udisks/udisks2, and at the moment, >> something functionally equivalent is rather missing from the lede user space >> world. >> >> Cheers, >> Karl P > > > > >> _______________________________________________ >> Lede-dev mailing list >> Lede-dev@lists.infradead.org >> http://lists.infradead.org/mailman/listinfo/lede-dev > > _______________________________________________ > Lede-dev mailing list > Lede-dev@lists.infradead.org > http://lists.infradead.org/mailman/listinfo/lede-dev > _______________________________________________ Lede-dev mailing list Lede-dev@lists.infradead.org http://lists.infradead.org/mailman/listinfo/lede-dev
