Re: [lustre-devel] RFC: Spill device for Lustre OSD

"Day, Timothy via lustre-devel" <[email protected]> Tue, 4 Nov 2025 21:11:39 +0000
Newsgroups org.lustre.lists.lustre-devel
Message-ID <[email protected]>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==