Gustav Brock
Gustav at cactus.dk
Fri Apr 9 05:42:34 CDT 2010
Hi Jim et al As Jumbo Frames may speed up transfer of large files, which indeed is the case when using iSCSI, I tried to locate some decent info on this and the do and don'ts. This seems quite good: http://www.smallnetbuilder.com/lanwan/lanwan-features/30201-need-to-know-jumbo-frames-in-small-networks <quote> Here are the key points for using jumbo frames on small networks: 1. Jumbo frames require gigabit Ethernet. 2. The highest frame size for a connection is the lowest end-to-end maximum frame size. 3. Gigabit Ethernet Layer 2 switches forward or drop jumbo frames; they don't fragment. 4. Fragmentation is a Layer 3 (routing) function. 5. TCP can adjust frame size between different devices. UDP can't. 6. Using jumbo frames for low latency applications (gaming, VoIP) can be counterproductive 7. Bigger isn't necessarily better. Jumbo frame sizes need to be matched to device computing power. </quote> If your equipment supports Jumbo Frames a speed increase of about 25% can be expected at no cost other than the time to carry out the adjustment: http://www.smallnetbuilder.com/lanwan/lanwan-reviews/30195-8-port-gigabit-switch-roundup?start=1 /gustav >>> accessd at shaw.ca 29-03-2010 01:01 >>> Even though I have not heard anything about iSCSI target, it does sound like a very descent product at a decent price. I have been slowly replacing my home office network with GByte LAN cards, switches and router. The internal performance is really stellar but Internet is only marginally improved but that is probably because my ISP throttles back performance... On a Linux box the performance should be better as there is less overhead than on Windows products. Keep me posted on what you learn and any performance and setup issues. Jim -----Original Message----- From: dba-tech-bounces at databaseadvisors.com [mailto:dba-tech-bounces at databaseadvisors.com] On Behalf Of Gustav Brock Sent: Sunday, March 28, 2010 2:21 PM To: dba-tech at databaseadvisors.com Subject: [dba-Tech] iSCSI Openfiler SAN Hi all Are any of you using iSCSI to attach network storage? I happened to locate this free server (iSCSI Target) which offers both SMB/CIFS (Windows share), iSCSI Target server, NFS, FTP, UPS, HTTP/WebDAV, LDAP, and rsync services, all controlled from a nice web interface: http://www.openfiler.com/ It seems to be well beyond the "normal" NAS appliances but is free to download and use from a single ISO install file or as ready-made machines for VMware - both in 32- and 64-bit. It runs on a rPath locked down Linux. Documentation is sparse (manual is €40 to buy) but I found this beginner's guide: http://www.petri.co.il/iscsi-san-vmware-esx.htm http://www.petri.co.il/use-openfiler-as-free-vmware-esx-san-server.htm http://www.petri.co.il/connect-vmware-esx-server-iscsi-san-openfiler.htm and this guide, How to connect your Windows 2008 Server & Vista PC to your iSCSI SAN: http://www.windowsnetworking.com/articles_tutorials/Connect-Windows-Server-2008-Windows-Vista-iSCSI-Server.html All very nice, but big question is of course performance? It could be fine to set up a box with an array of 2 TB drives and off we go. But? Would I need 10 Gbit NICs and switches? These are still quite expensive.