reo 4000, MS iscsi initiator throughput

[fthomas1973]

I have a windows 2003 server running BE 11d. I have a dedicated gbit nic for the public network and another gbit nic connected to a REO 4000 directly with a cat5e crossover cable. Most of the hosts I backup are conected via gbit nics. When I do backup to disk the best transfers I am seeing are 300 - 400 MB/min. In task manager my utilization for either of the nics is never above 5%. Shouldn't I be able to get better rates than this? What can I do to improve this?

 

[RMGBELGIUM]

Are the nics set at 1000 full, or autonegotiate ? you're getting 6 Mb/sec max, I would recommend setting the port speeds fixed to 1 GB.Also , when using iscsi, set jumboframes ( mtu = 9000 ) to increase your throughput.

rgds,

R.

 

[fthomas1973]

Are jumbo frames just set on the NIC connected to the iSCSI box?

 

[RMGBELGIUM]

jumboframes are set on the nic, and have to be supported on the switch as well.

 

[fthomas1973]

There is no switch involved. This is connected via a cross over cable. So to clarify do I only need to set jumboframes on the NIC that is directly connected to the iscsi box?

 

[xmsre]

I doubt the limitation is the channel. You'll hit disk bottlenecks log before filling 1Ge iSCSI. How is the disk configured in the iSCSI box?

Disk type
# of spindles
Raid configuration

 

[comtec17]

How are the disks setup? RAID5, RAID1+0 or 0+1, etc

How many spindles are there within the RAID group and how many LUNs are on each of these RAID Groups?

Did you align the LUNs prior to using them?

What is the default Block size set to on the disk being used for backup to disk?

 

[fthomas1973]

These are al helpful questions and I will answer them all at once--

The disks are RAID5 in 2 4 drive pool. It appears that there are 2 controllers-- 1 for each pool.

As far as alignment I don't believe I have any control over this on the iSCSI box itself. However I do believe that from a windows perspective the offset may be incorrect. Here are the diskpar results
diskpar -i 2
---- Drive 2 Geometry Infomation ----
Cylinders = 164135
TracksPerCylinder = 255
SectorsPerTrack = 63
BytesPerSector = 512
DiskSize = 1350056332800 (Bytes) = 1287514 (MB)

---- Drive Partition 0 Infomation ----
StatringOffset = 32256
PartitionLength = 1350056300544
HiddenSectors = 63
PartitionNumber = 1
PartitionType = 7

End of partition information. Total existing partitions: 1

Also I upgraded the NIC drivers/firmware. This made a huge difference. I am now seeing transfer rates of a 1Gb file using robocopy of 1400-1800Mb/min.

I would still like an opinion on whether this could be better and what offset/block size is suggested?