lacie "big disk and rh 7.3

[Rick Stevens]

chuck lawrence wrote:
> 
> please forgive me in advance if this has been discussed already...
> 
> I've got a pair of dual amd opteron systems (2.4.20-24.7smp kernel) that 
> I love dearly.  they're running rh 7.3.  I've just added a lacie 500gb 
> "big disk" using firewire (400?).  I've made it one huge partition 
> w/fdisk, and I do "modprobe ohci1394" before mounting it.
> 
> so far, so good.  it mounts just fine, but more or less randomly while 
> exercising the disk w/multiple large writes, the whole system freezes.

Does it come back or remain frozen?  Often on USB drives, the system
appears to freeze (well, it gets very sluggish) until the filesystem
caches get physically flushed out to the drive.  Then everything returns
to normal. What you're seeing may be similar (firewire and USB are both
serial interfaces).

> in addition, just now, it reported "No space left on device" when, in 
> fact, only 4% of the disk was used.  this seems to happen somewhere 
> between 7 and 8gb in any given dir.  starting again in a different dir 
> allows me to continue writing.  maybe this is some sort of quota?

Unless you enabled quotas on your system, that's not it.  It may be that
you're running out of inodes in the directory.  500GB for a single disk
is pretty big.  You might try to reformat and specify a larger number of
inodes (the "-N" option) or possibly specify the "-O dir_index" option
to make hashed b-trees for large directory lookup.

Another option is "-T largefile" or "-T largefile4" to have the system
tweak the filesystem based on 1 inode per megabyte (largefile) or 1
inode per 4 megabytes (largefile4).

> this is my first firewire excursion w/any os.  any thoughts or 
> experience out there?

As I said, the freeze issue may be similar to that on USB.  If so, once
the cache gets flushed, the system should respond again.  This is one of
the issues with serial interfaces--they're fast for read, large writes
slow down quite a bit.  The "out of space" is probably an inode issue as
500GB is a big drive.

Experimentation is your best bet here.  If you can sort it out, we'd
sure like to know so we can stick it in the FAQs on the RHIL website.
You'll get full credit, of course!
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- Rick Stevens, Senior Systems Engineer     rstevens at vitalstream.com -
- VitalStream, Inc.                       http://www.vitalstream.com -
-                                                                    -
-    Overweight:  When you step on your dog's tail...and it dies.    -
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