koskesh007
Cadet
- Joined
- Jul 30, 2012
- Messages
- 4
Finally got multipathing and round robin working using the following in /etc/multipath.conf
device {
vendor "FreeBSD"
product "iSCSI Disk"
path_grouping_policy multibus
path_selector "round-robin 0"
rr_min_io 1
}
test setup is:
- Dell R610 as XenServer host
- R710 running FreeNAS 8.2 Release version
- Each box has 3 gigabit links going to an exclusive iSCSI vlan, jumbo frames enabled and jumbo packet pings work.
- Round Robin is working as I can see in XenCenter performance graphs that all nics connected to iSCSI are utilized during file transfers.
- Windows 2008 R2 VM installed on local storage of xenserver
- FreeNAS is installed on 1 disk, and the storage pool is striped over 5 7200 rpm RE4 drives (RAID0 equivalent)
- A 50GB chunk of storage attached from SR sitting on FreeNAS 8.2 release version, and formatted with NTFS in the VM.
After enabling round robin I noticed a huge performance hit on read speed in ATTO (which happens to be the only benchmark tool that maxes out iSCSI multipathing in XenServer).
I get almost 200 MB/s WRITE for transfer sizes of 1024 KB and higher, but only 30 MB/s READ. Without round robin, using one path, ATTO speeds hover around 100 MB/s read and write.
I've also experimented with changing the rr_min_io from 1 to 4 but that doesn't make much difference.
I'm baffled. This is my first experiment with ZFS and I'm not sure if tuning is needed. I did this same exact experiment with Nexentastor (also ZFS based) and iSCSI multipathing with round robin working yielded 300 MB/s read/write using ATTO.
device {
vendor "FreeBSD"
product "iSCSI Disk"
path_grouping_policy multibus
path_selector "round-robin 0"
rr_min_io 1
}
test setup is:
- Dell R610 as XenServer host
- R710 running FreeNAS 8.2 Release version
- Each box has 3 gigabit links going to an exclusive iSCSI vlan, jumbo frames enabled and jumbo packet pings work.
- Round Robin is working as I can see in XenCenter performance graphs that all nics connected to iSCSI are utilized during file transfers.
- Windows 2008 R2 VM installed on local storage of xenserver
- FreeNAS is installed on 1 disk, and the storage pool is striped over 5 7200 rpm RE4 drives (RAID0 equivalent)
- A 50GB chunk of storage attached from SR sitting on FreeNAS 8.2 release version, and formatted with NTFS in the VM.
After enabling round robin I noticed a huge performance hit on read speed in ATTO (which happens to be the only benchmark tool that maxes out iSCSI multipathing in XenServer).
I get almost 200 MB/s WRITE for transfer sizes of 1024 KB and higher, but only 30 MB/s READ. Without round robin, using one path, ATTO speeds hover around 100 MB/s read and write.
I've also experimented with changing the rr_min_io from 1 to 4 but that doesn't make much difference.
I'm baffled. This is my first experiment with ZFS and I'm not sure if tuning is needed. I did this same exact experiment with Nexentastor (also ZFS based) and iSCSI multipathing with round robin working yielded 300 MB/s read/write using ATTO.
