Date: Wed, 8 Jan 2020 14:52:57 +0100 (CET) From: Wojciech Puchar <wojtek@puchar.net> To: Gary Jennejohn <gljennjohn@gmail.com> Cc: Rick Macklem <rmacklem@uoguelph.ca>, Hans Petter Selasky <hps@selasky.org>, Wojciech Puchar <wojtek@puchar.net>, "freebsd-hackers@freebsd.org" <freebsd-hackers@freebsd.org> Subject: Re: maximum MAXBSIZE Message-ID: <alpine.BSF.2.20.2001081452360.44533@puchar.net> In-Reply-To: <20200108105136.0d54ebce@ernst.home> References: <alpine.BSF.2.20.2001072210410.21107@puchar.net> <d79078c4-f1cb-93b9-ee6e-f689936c1e01@selasky.org> <YQBPR0101MB1427EEDE94AA6E34B49C3C09DD3F0@YQBPR0101MB1427.CANPRD01.PROD.OUTLOOK.COM> <20200108105136.0d54ebce@ernst.home>
next in thread | previous in thread | raw e-mail | index | archive | help
sorry i made a mistake - i change MAXPHYS not MAXBSIZE. 16MB works for now without problems On Wed, 8 Jan 2020, Gary Jennejohn wrote: > On Tue, 7 Jan 2020 22:47:54 +0000 > Rick Macklem <rmacklem@uoguelph.ca> wrote: > >> Hans Petter Selasky wrote: >>> On 2020-01-07 22:12, Wojciech Puchar wrote: >>>> default MAXBSIZE is 128kB. badly low for todays magnetic disks. >>>> >>>> i have it set to 2MB on all computers that have magnetic disks. Great >>>> improvement with large files. especially when more than one are >>>> read/wrote in parallel. And no problems experienced >>>> >>>> But for optimal performance MAXBSIZE should be transfered in few times >>>> longer than average seek time. todays disk do 200-250MB/s so 2MB is >>>> transfered below 10ms. >>>> >>>> 8-16MB seems like good choice. is there any reason not to set it that high? >>> >>> Old disk may not support it, especially USB 1.0/2.0 disks. >> I also thought it was limited to MAXPHYS, but maybe I'm only thinking of the NFS >> specific case? >> > > There's a comment in param.h that it should not exceed MAXPHYS to be > on the safe side. How old that comment is I can't say and that may > not be the case today. > > MAXBSIZE is only 64KiB in my param.h. > > I have to agree with HPS. There are many old bridge-chips still in > use and problems with a large MAXBSIZE might occur. It's certainly > not uncommon to see capacity limitations - I have a docking station > which can't see more than 3TB. > > -- > Gary Jennejohn > >
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?alpine.BSF.2.20.2001081452360.44533>