Messages in this thread | | | Date | Wed, 10 Apr 1996 21:43:28 -0500 (CDT) | From | "Christian Holtje <>" <> | Subject | Re: Overmounting a filesystem |
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On Wed, 10 Apr 1996, Jeff Voskamp [MFCF] wrote:
> If it's not in the root directory of the partition, put it on the same > partition as the parent directory. If it's at the root partition, put > it on the top partition. I was going to suggest the partition with the > most free space, but that needs too much smarts in the file system for > my taste. You may occasionally have to mount the overlays in different > locations to manually rebalance the loads. > > Hmmm.. how would mount handle this?
How about this for an off the cuff idea (well...I'm wearing a tee-shirt, but still....)
n devices(mountable) /dev/1, /dev/2 ... /dev/n mounted on /mnt in this order:
mount /dev/1 /mnt mount /dev/2 /mnt .... mount /dev/n /mnt
Flags (sysadmin set):
Reads: Getting the directory information in this order: Get direntry for this dir (if it exists) for /dev/1 "" "" 2 ......... "" "" n Cases to handle: If /dev/k has a direntry that matches an older direntry(/dev/1.../dev/k-1) then the older one is thrown out (therefore inaccessable).
Writes: Check if file exists, working /dev/n.../dev/1 Take FIRST occurance of a matching dirent.
If file doesn't exist, write to /dev/1
Cases to handle: /dev/k is RO: Try /dev/k+1 till /dev/n then report FS is RO.
/dev/k doesn't have enought space to write the WHOLE file. Write what is possible, continue on /dev/k+1, etc. untill you reach the end, then give outofspace error.
When file is closed, move all parts to one /dev/q, searching from /dev/1..../dev/n
If not enough space is available, then report an error.
I don't like this scheme, but it's just an idea...a start, I guess.
I don't like how writes are handled. Any ideas? (I'm just playing around.)
Christian G. Holtje (aka Doctor What)
--- --- --- --- - - - - --- ----- docwhat@itek.net + - + - + + + - + - + - CS major at Illinois * + * + * * + * +*+* +*+*+ * ---- finger me at ---- **** *** *** ** ** * * * * * docwhat@itek.net also: http://www.itke.net/~docwhat
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