nlehrer@ibb.gov (neil lehrer) writes
q1. how much of a performance hit does keeping quotas have? i'm thinking of hard quotas for users on their home dir thru home qtree, and, quotas for groups on the shared qtree. any other issues on quotas? our groups and users are kept in NIS.
Last discussed in the thread "quota overhead" c. 2000-12-01, I think. General concensus is that (these days) the performance overhead is pretty minor unless you have massive numbers of quota database entries.
Quotas per uid operative inside a single /home qtree are what I use: it works fine with c. 5000 entries. I would sound a caution about using quotas by gid, though: in practice we've found it's too easy for users to change gids of files accidentally or on purpose. We use separate qtrees for each "group filespace", but as has been pointed out, that imposes an upper bound on their number because of the limit of 254 qtrees per volume.
Use of NIS should be relevant only during the phase of "quota on" or "quota resize" when it's parsing /etc/quotas. You can use numeric uids & gids rather than names in /etc/quotas, regardless.
Chris Thompson University of Cambridge Computing Service, Email: cet1@ucs.cam.ac.uk New Museums Site, Cambridge CB2 3QG, Phone: +44 1223 334715 United Kingdom.