In setting up tmpfs (so not tmpmfs) on a machine that is using zfs(v15, zfs v4) on 8.2prerelease I run out of space on the tmpfs when copying a file of ~4.6 GB file from the zfs-filesystem to the memory disk. This machine has 8GB of memory backed by swap on the harddisk, so I expected the file to copy to memory without problems.
Below in detail what happens: upon rebooting the machine the tmpfs has 8GB available as can be seen below: --- h...@pulsarx4:~/ > df -hi /tmp Filesystem Size Used Avail Capacity iused ifree %iused Mounted on tmpfs 8.2G 12K 8.2G 0% 19 39M 0% /tmp --- Subsequently copying a ~4.6GB file from a location in the zfs-pool to the memory filesystem fails with no more space left message --- h...@pulsarx4:~/ > cp ~/temp/large.iso /tmp/large_file cp: /tmp/large_file: No space left on device --- After this the tmpfs has shrunk to just 2.7G, obviously much less than the 8.2G available before the copy-operation. At the same time there are still free inodes left, so that does not appear to be the problem. Output of the df after the copy: --- h...@pulsarx4:~/ > df -hi /tmp Filesystem Size Used Avail Capacity iused ifree %iused Mounted on tmpfs 2.7G 2.7G 1.4M 100% 19 6.4k 0% /tmp --- A quick search shows the following bug-report for solaris: http://bugs.opensolaris.org/bugdatabase/view_bug.do;jsessionid=e4ae9c32983000ef651e38edbba1?bug_id=6804661This appears closely related as here I also try to copy a file >50% of memory to the tmpfs and the way to reproduce appears identical to what I did here. As it might help spot the problem: below the information on the zfs ARC size obtained from the output of zfs-stats. This gives: Before the copy: --- System Memory Statistics: Physical Memory: 8161.74M Kernel Memory: 511.64M DATA: 94.27% 482.31M TEXT: 5.73% 29.33M ARC Size: Current Size (arcsize): 5.88% 404.38M Target Size (Adaptive, c): 100.00% 6874.44M Min Size (Hard Limit, c_min): 12.50% 859.31M Max Size (High Water, c_max): ~8:1 6874.44M --- After the copy: --- System Memory Statistics: Physical Memory: 8161.74M Kernel Memory: 3326.98M DATA: 99.12% 3297.65M TEXT: 0.88% 29.33M ARC Size: Current Size (arcsize): 46.99% 3230.55M Target Size (Adaptive, c): 100.00% 6874.44M Min Size (Hard Limit, c_min): 12.50% 859.31M Max Size (High Water, c_max): ~8:1 6874.44M --- Unfortunately I have difficulties interpreting this further than this, so suggestions how to prevent this behavior (or further trouble shoot this) would be appreciated as my feeling is that this should not happen. _______________________________________________ [email protected] mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-stable To unsubscribe, send any mail to "[email protected]"
