CIFS robocopy freezes

[czartangus]

Running Freenas 8.04 x64 (10351) and working very well for the most part. The only outstanding issue is when I copy files to any CIFS share I notice the copy process freezes every couple of seconds. Initially I thought this was the onboard nic or switch. After swapping both devices the issue still remains. I really have no clue what is cause this freeze every couple of seconds. When I wrote 100 gig file using DD it took 158 minutes. It average out to about 11 mb/s which seems extremely slow….I listed out my hardware plus some test I ran to help troubleshot the issue. Not sure what to do next and I’m hoping someone can point me in the right direction.

Hardware:
Motherboard: Supermicro C2SBC-Q
CPU: Intel Core 2 Duo CPU E7600 @ 3.06GHz
RAM: 8 GB
NIC: onboard Intel 82566DM Gigabit
SAS/SATA Controller: 2 IBM ServeRAID M1015 LSI9220-8i 46M0861
HDD Cage: 3 iStarUSA BPN-DE340SS SAS/SATA 6 gb/s Trayless Hot-Swap cage
Drives: 4GB CF (Freenas OS) – connected to onboard sata controller
Drives: 8 1TB configured for raidz – connected to IBM SAS controllers


100 gig write test on zraid:
dd if=/dev/zero of=/mnt/store01/testfile.out bs=2048k count=50k
51200+0 records in
51200+0 records out
107374182400 bytes transferred in 9467.101877 secs (11341822 bytes/sec)

100 gig read test on zraid:
dd if=/mnt/store01/testfile.out of=/dev/null bs=2048k count=50k
51200+0 records in
51200+0 records out
107374182400 bytes transferred in 363.918849 secs (295049797 bytes/sec)

 

[czartangus]

I think I figured out what is causing the intermittent freezing during a copy. I believe it’s due to a single bad drive in the array. Initially I was coping large files around 4gigs and it was not apparent but now I’m sending over a bunch of smaller files. I notice every time the freeze would happen a specific hard drive activity led was active. The activity led would turn off and the copy job resumes...I’m not seeing any hard drive errors but does anyone know how I can confirm this is a bad drive?