From: Chris Torek Date: Thu, 25 Feb 2021 07:57:36 GMT Subject: Re: [PATCH] read-cache: make the index write buffer size 128K Message-ID: In-Reply-To: On Wed, Feb 24, 2021 at 11:36 PM Neeraj Singh wrote: > From a quick perusal of freebsd, st_blksize seems to be the system > PAGE_SIZE by default (4k most of the time, I assume). The Windows > equivalent of this value is really tuned to what you want to send down > when bypassing the cache (to avoid partial cluster/stripe writes). It's page-size for pipes, sockets, etc., but for real files, it's based on a report from the underlying file system. It's actually 8k on a typical ancient UFS file system, 64K on UFS2, and 128K on ZFS, on FreeBSD. > https://pubs.opengroup.org/onlinepubs/9699919799/basedefs/sys_stat.h.html > doesn't elicit much confidence. The units of st_blksize aren't even > defined. Despite POSIX's rather obstreperous definition of st_blksize, the units are actually just bytes, in practice. Chris