mdconfig device no faster then direct disk ...

[Marc G. Fournier]

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On a machine that is doing 0 swapping:

last pid: 47437;  load averages:  0.01,  0.01,  0.00 

45 processes:  1 running, 44 sleeping
CPU states:  0.0% user,  0.0% nice,  0.4% system,  0.4% interrupt, 99.2% idle
Mem: 35M Active, 285M Inact, 271M Wired, 44K Cache, 111M Buf, 402M Free
Swap: 2007M Total, 2007M Free

I just did:

mdconfig -a -t malloc -s 200m -o reserve
newfs /dev/md0

Now, my understanding, this builds a file system 'in core', vs on the disk ... 
with memory being faster then disk, I would have assumed that read/write 
performance would have been better, but, using iozone, I'm not finding enough 
of a difference in performance to understand why I'd want to use a memory file 
system:

aster# pwd
/usr
aster# iozone 180 | grep "the file"
        It then reads the file.  It prints the bytes-per-second
Reading the file...1.007812 seconds
        54658803 bytes/second for writing the file
        187280550 bytes/second for reading the file
aster# pwd
/usr
aster# cd /mnt
aster# df .
Filesystem 1K-blocks Used  Avail Capacity  Mounted on
/dev/md0      198126    4 182272     0%    /mnt
aster# iozone 180 | grep "the file"
        It then reads the file.  It prints the bytes-per-second
Reading the file...0.984375 seconds
        60701485 bytes/second for writing the file
        191739611 bytes/second for reading the file

Am I missing something here?  Or is this expected?

- ----
Marc G. Fournier           Hub.Org Networking Services (http://www.hub.org)
Email . scrappy at hub.org                              MSN . scrappy at hub.org
Yahoo . yscrappy               Skype: hub.org        ICQ . 7615664
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