# unmounting xfs crashes whole system



## witek (Apr 6, 2009)

Hi,

I am new to BSD family, however I wanted to try how it works. I tested two FreeBSD-derived desktop-oriented products: PCBSD and DesktopBSD some time ago and noticed that using XFS partition crashes the whole system to give reboot, which I reported on their fora. I was informed that XFS write support is only experimental and it should not be mounted for writing. Today I examined the latest stable release of FreeBSD 7.1.

I just mounted manually my XFS partition without giving explicitly 'write' option. It turned out it was mounted with write access however. I succesfully created several files then I typed 'umount this_partition' and the whole system rebooted.

This is insane. Why - if the support for writing XFS partition is experimental only - FreeBSD mounts it for writing by default? And why unmounting causes reboot?? How is supposed FBSD to be considered stable if simply unmounting a filesystem crashed the whole system?


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## phoenix (Apr 7, 2009)

Hence the term *experimental*, also known as "use at your own risk", or "be careful, or this may eat your homework, break all your dishes, run over your neighbour's dog, and drive your car into the river".  

All filesystems are mounted read-write by default, even CD/DVD-ROMs, although the kernel detects a read-only medium and mounts it read-only.  You have to specify read-only, if you want read-only.  This has been the default since the dawn of computing, possibly even the dawn of time.

Very little work has gone into supporting "alien" filesystems like ext3, reiserfs, xfs, ntfs, and so on.  No one needs them enough to delve into their inner working, and get them into a usable state.  Everyone is, apparently, content with UFS, ext2, iso9660, udf, FAT, and ZFS.


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