> there is one known issue on Unix like systems which may lead to > the > case where a file system without file entries may report no > available > space. I do not know if this is the reason for your trouble, but > it > it's better to tell about, as this is not known to all Unix users. > > On Unix like systems it is possible to create (or open a file) and > remove the directory entry (unlink) while holding the file still > open. > As long as you do not close all references to the same file > descriptor > the file continues to exist and claims space on the file system. > Nobody > else can see this file or reclaim the space. Only the process who > holds > the file open (or processes if forked and file descriptor > inherited) > can reclaim the space of such an file. As soon as all references of > the > file are closed (may be due to exiting/killing the holding process) > the > used space is reclaimed and everything is back fine. > > Some years ago I had trouble on a RAM file system which got full > during > usage, but every time I tried to look into this, there was enough > free > space. The reason for this: Opening the telnet session closed the > process holding the open file. After a long time of debugging a
uh! a real heisenbug. > misbehaved file rotating was localized for the bug. The process > rotated the file names but forgot to close the original file and > more > data got appended to the old (invisible) file, while the testing > loop > checked the new (empty) file for it's size to trigger next file > rotation ... a trigger which never occurred while the new file > stayed > empty as all new data still got appended to the old file ... until > file > system space exhausted :( > > In case this helps to narrow down your trouble. > > Harald thank you very much for telling the story behind it. bye, bastian _______________________________________________ openwrt-devel mailing list openwrt-devel@lists.openwrt.org https://lists.openwrt.org/mailman/listinfo/openwrt-devel
