Mounting two different disk slices on the same mount point
Hello FreeBSD gurus, Some linux guy gave me a strange idea: You have two disks, /dev/da1s1e and /dev/da2s1e and I mount the two to a single mount point. Do I end up with the total capacity of the two disks on the said mount point? To be a bit clear, da1 is, say, 36GB and da2 is 72GB and I mount as above to /mnt Does /mnt now have 108GB? What are the dangers of doing this? How does the system use the disks? I haven't tested this anyway. Is this something sane? Clues will be highly appreciated. -Wash http://www.netmeister.org/news/learn2quote.html -- +==+ |\ _,,,---,,_ | Odhiambo Washington[EMAIL PROTECTED] Zzz /,`.-'`'-. ;-;;,_ | Wananchi Online Ltd. www.wananchi.com |,4- ) )-,_. ,\ ( `'-'| Tel: +254 20 313985-9 +254 20 313922 '---''(_/--' `-'\_) | GSM: +254 722 743223 +254 733 744121 +==+ San Francisco, n.: Marcel Proust editing an issue of Penthouse. ___ [EMAIL PROTECTED] mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to [EMAIL PROTECTED]
Re: Mounting two different disk slices on the same mount point
On Sat, Aug 07, 2004 at 01:36:39PM +0300, Odhiambo Washington wrote: Hello FreeBSD gurus, Some linux guy gave me a strange idea: You have two disks, /dev/da1s1e and /dev/da2s1e and I mount the two to a single mount point. Do I end up with the total capacity of the two disks on the said mount point? To be a bit clear, da1 is, say, 36GB and da2 is 72GB and I mount as above to /mnt Does /mnt now have 108GB? What are the dangers of doing this? How does the system use the disks? I haven't tested this anyway. Is this something sane? Clues will be highly appreciated. That sounds a bit muddled. If you try mounting two partitions literally in the same place, either one will overlay the other so you can only access the last mounted partition, or you'll get an error message and fail to mount the second one. (Which occurs depends on the filesystem type). What I think your Linux using friends were thinking of, even if they were unclear on the concept, is some form of logical volume management. Under FreeBSD, you could use vinum(8) to create a concat volume from the two partitions, which would give you give you a filesystem the size of the sum of both components. That's not new functionality. It's been available in FreeBSD for ages (since 2.x I believe) through vinum(8) or one of it's predecessors like ccd(4). Cheers, Matthew -- Dr Matthew J Seaman MA, D.Phil. 26 The Paddocks Savill Way PGP: http://www.infracaninophile.co.uk/pgpkey Marlow Tel: +44 1628 476614 Bucks., SL7 1TH UK pgp6U0UJJWZ8y.pgp Description: PGP signature
