Date: Sat, 08 Jan 2005 10:31:49 -0700 From: Scott Long <scottl@freebsd.org> To: Barath S <barath_yes@yahoo.com.sg> Cc: FreeBsd-MailGrp <freebsd-fs@freebsd.org> Subject: Re: using mfs of size > 64Mb and system stability Message-ID: <41E01905.3040200@freebsd.org> In-Reply-To: <20050107095005.4797.qmail@web30308.mail.mud.yahoo.com> References: <20050107095005.4797.qmail@web30308.mail.mud.yahoo.com>
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Using the swap option really is the preferred method. The available kernel malloc pool is limited and is scaled on the amount of system RAM that you have; on my 256MB laptop, it's reporting only 85MB available for kernel malloc. So this would explain why trying to malloc 128MB for md could fail =-). With the swap option, pages are allocated from the buffer/cache and held there. They are only swapped to disk when the system is under memory pressure, otherwise they stay in RAM. Scott Barath S wrote: > Thank you Arne. > I didn't try with 'swap' option as my requirement is > to have the files in memory. I will test with 5.3 and > see it that works. > regards > --- Arne Wörner <arne_woerner@yahoo.com> wrote: > >>--- Barath S <barath_yes@yahoo.com.sg> wrote: >> >>>My intention is create a file system in memory of >> >>size >> >>>>128Mb and use that for my application. But, I >>> >>>couldn't do that as my system hangs whenever I >> >>create >> >>>a mfs of size > 64Mb. I did the following... >>> >>>a) Configured memory file system of size 128Mb >> >>using >> >>>'mdmfs' command with 'malloc' option. When I tried >> >>to >> >>>copy files to this mfs, m/c hanged after copying >> >>some >> >>>files. >>>b) Then I rebooted by m/c and configured memory >> >>file >> >>>system of size 64Mb and this time the copying >>>operation was successful >>>c) I observed that the system hanged whenever I >>>configure a mfs of size > 64Mb and used that mfs >>> >>>a) Can someone provide me hints on what could be >> >>the >> >>>problem ? >>> >> >>I use R5.3. According to the man page mdconfig(8) a >>md of type >>malloc should use "-o reserve", if it is large and >>to be "filled" >>(I think the man page means "filled quickly"): >> "If the -o reserve option is not set, creating and >>filling >> a large malloc-backed memory disk is a very easy >>way to >> panic a system." >> >>Maybe that helps? >> >>Did you try type "swap"? >> >>-Arne >> >> >> >> >>__________________________________ >>Do you Yahoo!? >>The all-new My Yahoo! - Get yours free! >>http://my.yahoo.com >> >> >> > > > __________________________________________________ > Do You Yahoo!? > Download the latest ringtones, games, and more! > http://sg.mobile.yahoo.com > _______________________________________________ > freebsd-fs@freebsd.org mailing list > http://lists.freebsd.org/mailman/listinfo/freebsd-fs > To unsubscribe, send any mail to "freebsd-fs-unsubscribe@freebsd.org"
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