On 7/1/23 01:16, Bruce Momjian wrote: > On Fri, Jun 30, 2023 at 04:04:57PM -0700, Andres Freund wrote: >> Hi, >> >> On 2023-06-30 18:58:20 -0400, Bruce Momjian wrote: >>>> [1] On linux I think you need to use stat() to figure out the st_dev for a >>>> file, then look in /proc/self/mountinfo for the block device, use the name >>>> of the file to look in /sys/block/$d/queue/physical_block_size. >>> >>> I just got a new server: >>> >>> https://momjian.us/main/blogs/blog/2023.html#June_28_2023 >>> >>> so tested this on my new M.2 NVME storage device: >>> >>> $ /sys/block/nvme0n1/queue/physical_block_size >>> 262144 >> >> Ah, I got the relevant filename wrong. I think it's logical_block_size, not >> physical one (that's the size of addressing). I didn't realize because the >> devices I looked at have the same... > > That one reports 512 _bytes_ for me: > > $ cat /sys/block/nvme0n1/queue/logical_block_size > 512 >
What does "smartctl -a /dev/nvme0n1" say? There should be something like this: Supported LBA Sizes (NSID 0x1) Id Fmt Data Metadt Rel_Perf 0 - 4096 0 0 1 + 512 0 0 which says the drive supports 4k and 512B sectors, and is currently configures to use 512B sectors. regards -- Tomas Vondra EnterpriseDB: http://www.enterprisedb.com The Enterprise PostgreSQL Company
