Thiemo --

I'm not familiar with RocketRaid. Is it handling the RAID for you, or  
are you using MD?

Thanks, all, for your feedback! I'm still surprised nobody has tried  
this on one of these Sun boxes yet. I've signed up for some demo  
hardware. I'll post what I find.

Norman


On Dec 18, 2007, at 2:34 PM, Thiemo Nagel wrote:

Dear Norman,

quoted

quoted

So... we're curious how Linux will handle such a beast. Has anyone  
run MD software RAID over so many disks? Then piled LVM/ext3 on  
top of that? Any suggestions?

Are we crazy to think this is even possible?

I'm running 22x 500GB disks attached to RocketRaid2340 and NFORCE- 
MCP55
onboard controllers on an Athlon DC 5000+ with 1GB RAM:

9746150400 blocks super 1.2 level 6, 256k chunk, algorithm 2 [22/22]

Performance of the raw device is fair:
# dd if=/dev/md2 of=/dev/zero bs=128k count=64k
65536+0 records in
65536+0 records out
8589934592 bytes (8.6 GB) copied, 15.6071 seconds, 550 MB/s

Somewhat less through ext3 (created with -E stride=64):
# dd if=largetestfile of=/dev/zero bs=128k count=64k
65536+0 records in
65536+0 records out
8589934592 bytes (8.6 GB) copied, 26.4103 seconds, 325 MB/s

There were no problems up to now.  (mkfs.ext3 wants -F to create a  
filesystem larger than 8TB.  The hard maximum is 16TB, so you will  
need to create partitions, if your drives are larger than 350GB...)

Kind regards,

Thiemo Nagel