Am 11. April 2017 08:21:31 MESZ, schrieb Uwe Sauter <uwe.sauter...@gmail.com>: > >Ray, > >if you're going with the easy "copy" method just be sure that the nodes >are all in the same state (user management-wise) before >you do your first copy. Otherwise you might accidentally delete already >existing users. > >I also encourage you to have a look into Ansible which makes it easy to >copy files between nodes (and which helps not to forget a >node when updateing the files). > > >Regards, > > Uwe > >Am 11.04.2017 um 08:17 schrieb Raymond Wan: >> >> Dear all, >> >> Thank you all of you for the many helpful alternatives! >> >> Unfortunately, system administration isn't my main responsibility so >> I'm (regrettably) not very good at it and have found LDAP on Ubuntu >to >> be very unfriendly to set up. I do understand that it must be a good >> solution for a larger setup with a full-time system administrator. >> But, if I can get away with something simpler for a cluster of just a >> few nodes, then I might try that instead. >> >> So far, no one seems to discourage me from simply copying /etc/passwd >> between servers. I can understand that this solution seems a bit >> ad-hoc, but if it works and there are no "significant" downsides, I >> might give that a try. In fact, perhaps I'll give this a try now, >get >> the cluster up (since others are waiting for it) and while it is >> running play with one of the options that have been mentioned and see >> if it is worth swapping out /etc/passwd for this alternative... I >> guess this should work? >> >> I suppose this isn't "urgent", but yes...getting the cluster set up >> with SLURM soon will allow others to use it. Then, I can take my >time >> with other options. I guess I was worried if copying /etc/passwd >will >> limit what I can do later. I guess if Linux-based UIDs and GIDs >> match, then I shouldn't have any surprises? >> >> Thank you for your replies! They were most helpful! I thought I had >> only two options for SLURM: /etc/passwd vs LDAP. I didn't realise >of >> other choices available to me. Thank you! >> >> Ray >> >> >> >> >> On Tue, Apr 11, 2017 at 2:05 PM, Lachlan Musicman <data...@gmail.com> >wrote: >>> On 11 April 2017 at 02:36, Raymond Wan <rwan.w...@gmail.com> wrote: >>>> >>>> >>>> For SLURM to work, I understand from web pages such as >>>> https://slurm.schedmd.com/accounting.html that UIDs need to be >shared >>>> across nodes. Based on this web page, it seems sharing /etc/passwd >>>> between nodes appears sufficient. The word LDAP is mentioned at >the >>>> end of the paragraph as an alternative. >>>> >>>> I guess what I would like to know is whether it is acceptable to >>>> completely avoid LDAP and use the approach mentioned there? The >>>> reason I'm asking is that I seem to be having a very nasty time >>>> setting up LDAP. It doesn't seem as "easy" as I thought it would >be >>>> [perhaps it was my fault for thinking it would be easy...]. >>>> >>>> If I can set up a small cluster without LDAP, that would be great. >>>> But beyond this web page, I am wondering if there are suggestions >for >>>> "best practices". For example, in practice, do most administrators >>>> use LDAP? If so and if it'll pay off in the end, then I can >consider >>>> continuing with setting it up... >>> >>> >>> >>> We have had success with a FreeIPA installation to manage auth - >every node >>> is enrolled in a domain and each node runs SSSD (the FreeIPA >client). >>> >>> Our auth actually backs onto an Active Directory domain - I don't >even have >>> to manage the users. Which, to be honest, is quite a relief. >>> >>> cheers >>> L. >>> >>> ------ >>> The most dangerous phrase in the language is, "We've always done it >this >>> way." >>> >>> - Grace Hopper >>>
Indeed, look into ansible and avoid "ad-hoc". Ansible has a module "user" to handle that case with grace -- no accidental overwriting. Regards , Benjamin -- FSU Jena | JULIELab.de/Staff/Benjamin+Redling.html vox: +49 3641 9 44323 | fax: +49 3641 9 44321
