Note: "permalinks" may not be as permanent as we would like,
direct links of old sources may well be a few messages off.
Il 12/05/2016 17:58, Gaudenz Steinlin ha scritto: > > Hi Hi > I ran into the same problem someone > else previously reported here today: > http://lists.linbit.com/pipermail/drbd-user/2016-May/022909.html that's me, and others before > I then looked into the code to better understand how drbdmanage > calculates the free space and discocered that the code makes wrong > assumptions about how lvmthin metadata allocation works. As described in > the lvmthin(7) manpage a thin pool lv actually consists of 2 hidden > lv's, one for the actual data and another much smaller one for metadata. > > But the code in storage/lvm_thinlv.py calculates the free space as > > total_space - %data_used*total_space - %metadata_used*total_space - %snap_used*total_space > > Where total_space is the size of the data LV on the thin pool lv. > > This is wrong because metadata is not allocated from the data lv and > should not be considered in this calculation. I had a thin pool which > was 50% full and the metadata was also 50% which resulted in 0 free > space :-(. See below for the actual relevant code. > > IMO the free space should be calculated without even considering > metadata space used. If you want to make sure that there is enough > metadata space available this needs to be done in a separate > calculation. > > I verified that removing meta_used on line 285 solves the problem and > drbdmanage then reports the correct free space. You are right, imho. In my case total data space is 1,6TB , total metadata size is 100MB. It doesn't make sense to apply metadata percentage to total data size. The code you are quoting is taken from the update_pool function that recalculates free space (drbdmanage update-pool), and appears to be the same inside the current version form package drbdmanage 0.95-1 inside current pve 4.2: It is still the same code inside latest drbdmanage upstream ( http://www.drbd.org/download/drbdmanage/drbdmanage-0.95.tar.gz ) bye, rob