The underlying device in this context is the NSD, network storage device. This has relation at all to 512 byte or 4K disk blocks. Usually around a meg, always a power of two. -- ddj Dave Johnson > On Mar 21, 2019, at 9:22 AM, Dorigo Alvise (PSI) <alvise.dorigo at psi.ch> wrote: > > Hi, > I'm a little bit puzzled about different meanings of blocksize for different GPFS installation (standard and gnr). > > From this page https://www.ibm.com/developerworks/community/wikis/home?lang=en#!/wiki/General%20Parallel%20File%20System%20(GPFS)/page/File%20System%20Planning > > I read: > The blocksize is the largest size IO that GPFS can issue to the underlying device > A subblock is 1/32nd of blocksize. This is the smallest allocation to a single file > For non-gnr GPFS device is quite clear to me (I hope): it is a single spinning disk (or ssd). And I verified this on a small cluster composed of nsd using their local hard drive. > > Can someone explain what is the "device" in the case of GNR ? a single pdisk ? > > Thanks, > > Alvise > > _______________________________________________ > gpfsug-discuss mailing list > gpfsug-discuss at spectrumscale.org > http://gpfsug.org/mailman/listinfo/gpfsug-discuss -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://gpfsug.org/pipermail/gpfsug-discuss_gpfsug.org/attachments/20190321/f4a281a8/attachment.html>