Date: Sat, 21 Sep 2002 09:44:12 -0400 From: Matt Smith <webmaster@forsetti.com> To: freebsd-questions@freebsd.org Subject: Re: Using MFS for the first time Message-ID: <3D8C77AC.7080006@forsetti.com> References: <200209211038.g8LAcube080287@lurza.secnetix.de>
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What is the /dev/null component in the MFS line below? I have seen the swap slice used, but never /dev/null. For that matter, I don't even really know what that component does -- why do I need to list a device for a RAM disk? Could someone fill in my knowledge gap? Thanks -Matt Oliver Fromme wrote: > Joseph <mystical@houston.rr.com> wrote: > > Okay, so I've been using Windows, so what?! Sure it crashes alot, and > > has a serious number of fatal errors, but it compatible with an easy to > > configure Ram-disk program. In a matter of seconds, i had a virtual > > drive running off of my 512 mb of spare ram. > > That's right, the old RAM-Disk driver even existen in the > old DOS days, 15 years ago, and that's where it belongs. > It is static and non-swappable. Not even perfect for a > single-tasking system like DOS. ;-) > > > Okay, so maybe i exaggerate a little. I'm not too fond of Windows. > > Freebsd is the best choice i've made by far. However, i am quite new to > > MFS usages, and Kernel compilations. I'm hoping that an expert in this > > field can point out the pro's and con's, usages of, maintenance of MFS. > > Btw, this is just a standalone system, a personal computer, u might say. > > I'm not an expert, but I'm using MFS myself. It's pretty > easy to set up: Add a line like this to your /etc/fstab > file: > > /dev/null /tmp mfs rw,nosuid,nodev,-s=204800,-m=0,-T=minimum 0 0 > > The number behind "-s=" specifies the maximum size in disk > blocks, where one block is 512 bytes. In the above example, > the MFS filesystem would be 100 Mbytes. It is mounted on > /tmp, which is the typical usage for an MFS. > > Pros: Well, it's faster than a physical disk, as long as > there is enough RAM to back up the data. If you run out > of RAM, the contents of the MFS are (partially) paged to > the swap area on your harddisk, just like a normal process > (and unlike the DOS RAMdisk driver). > > Cons: If you're really low on RAM, and MFS won't do you > any good -- quite the opposite: It takes up valuable RAM > which ends up being paged to disk anyway if there's not > enough RAM left. > > Another disadvantage is that the contents of the MFS are > lost when the machine reboote (obviously). On the other > hand it could be seen as an advantage, as the contents of > /tmp don't have to be cleaned after a reboot. > > Be careful not to mount an MFS on /var/tmp, because this > directory is expected by several tools to survive a reboot > (for example to save vi editor sessions)! > > Regards > Oliver > To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-questions" in the body of the message
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