> I recall that there is an 8T limit on the size of an OST. Is > that just for Lustre 1.6? Or also 1.8 and 2.0? Now that we > are starting to get 2T drives, is there any way to exceed 8T? > Thanks. [ ... ]
While I have seen Lustre developers recommend having few large OSTs, queries like this seem to me to be based on assuming that 'fsck' (or "resilvering" in the futurea) of the OSTs is never needed. Good luck with that. One of the advantages of Lustre, which applies regardless of the clustering aspect, is that OSTs can be checked in parallel. There is a good argument that for 'fsck' purposes file systems should not be larger than one disk; because 'fsck'ing, unlike large or parallel reading or writing, does not scale well on RAID, and the ratio of disc arms per TB is ever shrinking. Sure, OSTs have a significant fixed overhead in Lustre, yet Lustre implementors should consider carefully how long their clients are prepared to wait for a damaged OST to be checked or reloaded from backup. _______________________________________________ Lustre-discuss mailing list [email protected] http://lists.lustre.org/mailman/listinfo/lustre-discuss
