cpanel, iSCSI and backup

[bangsters]

Hi.

We have started migrating our servers to utilize our iscsi configuration. However, we are experiencing some issues with whm/cpanel on two of our servers. The cpanel servers are setup via iSCSI LUNs and have no local hdds. Connection to the iscsi network is via gig nic. Everything runs fine off our iscsi traffic, but when cpanel performs backup it eats the bandwidth. And since it's 2 cpanel servers running nightly backups, the bandwidth is like being slashed in 4 (data takes bandwidth to get to server to get processed (converted to tgz), then sent back to iscsi storage, multiply that by 2 servers), thereby affecting performance during backup.

Is anyone else configured the same way? How do you guys run your cpanel backup? running backup is killing the traffic and speeds.

Any suggestions?

Thanks

[ffeingol]

Just a question on your config. Are you iSCSI connections on different NIC's than your internet traffic? You also said that you have gig NIC's for the iSCSI. I'm making the assumption that it's also a gig switch port? Have you checked that everything along the path actually negotiated (or you hard coded it) to gig?

[bangsters]

We use a separate gig switch for our iscsi traffic. The gig nics also are running at 1Gps/Full Duplex as specified in ethtools (I did not manually set to gig speed, it's set at auto neg although it shows that it's connecting at gig full duplex).

The switch is a netgear unmanaged gig switch, and the nics of the servers are intel server adapters. The iscsi server uses 4 WD Caviar Blacks in raid 5, we'll add more drives once we utilize the capacity but for now 3TB is enough for our needs.

Anyone else with a similar setup?

[ffeingol]

We're just starting to test with our iSCSI SAN. We use it with non-cPanel things with no issues. Our backups are to a different server so we don't have the exact same situation.

A couple of thoughts:

- Do you have jumbo packets enabled? That gave our backups a huge boost (with our backup server)

- Are you using a commercial SAN or one of the freeware ones? (just helps to compare).

[bangsters]

jumbo packets are currently disabled as one of the nic cards don't support it.

we use an appliance for iscsi.

[4u123]

Did you resolve this issue? I'm thinking of setting up a similar situation.

If you dont mind me asking, how are you backing up / duplicating your storage? If you are using one large array isnt that a pretty big single point of failure?

I'd like to know more about how people have set this up - one large partition or lots of seperate ones? Are you using virtualization or is this is ths just a standard mass storage solution for you?