Duke (4th November 2009)
REF - Cabling - You have two technologies to choose from IPMP and LACP.
LACP 802.ad will effectively load balance over interfaces
IPMP will provide failover (with a small performance increase on outbound traffic)
For best Availability & Performance
You will need a redundant switch stack (eg Cisco 3750/Nortel 5500) and just use LACP.
If you have two independent switches
You could just use IPMP, but you could use both LACP and IPMP together. See example here
Problem is that you will run out of NIC ports quite quickly.
Duke (4th November 2009)
On my 7110 I have 3x1GB LACP links for CIFS (I only use it for CIFS at presnet) and then the last 1 GB Link is to our backup LAN where our NAS boxes and backup stuff lives so I can actually backup in the day as well as night without causing delays or too much load (not that it wouldn't manage to cope as it flys)
Cheers, I'd planned on using LACP for the links but will investigate IPMP too. On that diagram you linked to, which IP address would actually be used to communicate with the SAN? Does IPMP tie the two LACP links together and the LACP connections themselves aren't actually used directly?
John or Andy, how do you then handle DNS hostnames (or IP addresses) for the separate links? Obviously the SAN itself has to have a hostname, do you bind a different DNS name to the 'other' IP address that you're using for something else (e.g. backup in your case John) or just specify the other link via IP address on the backup server?
Many thanks, it's really appreciated.
We have 3xNICs in an LACP link and 1 that is currently used for management but could be used for CIFS. The LACP link is carrying all of our iSCSI traffic for our VMs, 2x File servers, 2x DC's, Citrix and a couple of test boxes and it hardly breaks a sweat.
DNS/IP addresses, I'm flexible on this, just depends what's accessing the devices.
- NFS/CIFS clients I would create a DNS entry for the IPMP device ( if no IPMP then aggregate.)
- VMWARE (iSCSI/NFS) and replication between devices, then I'm happy with IP addresses.
The 1x standalone one again has 1 IP (different range completly) and I just access it via IP IE \\172.16.10.200\share_name and it works fine. It does appear on that LAN as SAN-01 though so its not a problem at all for us.
Thanks all, very much appreciated!
I'll use IP addresses if necessary, but if I did go for multiple DNS hostnames (e.g. sancifs, sanmgmt) does anyone know if this would cause communication problems with the box as the hostname being used to communicate is different from the hostname specified on the device? I have some software/hardware that always refers to the 'local' hostname and will redirect you to that when you click a link on the BUI even if the address you originally went to was different.
What mirroring / redundancy options are available on a pair of 7110 2tb SANs?
I originally bought a pair of these SAN's based on a project that was to create a new building with a second server room and have a SAN in server room building 1 and a san in server room building 2 and both of them mirroring - but the entire new building plan got shelved, and so I am left with both SAN's in the same rack of my only server room. *sigh*
Not ideal!!! But better than nothing.
This storage is only being used for VM's over NFS. (no CIFS or iSCSI). So what do you knowledgable guys thing is the best way for me to configure it so that my VMs are mirrored across both SANS so that if one san does go down I will be able to access the VM's off the second SAN straight away. I see in the interface there is "Replication" and also on the filesystem there is "Snapshots" but I don't know what does what. This is what I am aiming for. Can it be done?
I have not had time to do proper research into getting this configured on 7110, I have 6 big projects on at the moment as well as the day to day stuff, and Offstead in in January. As you can imagine I am struggling somewhat!!!! If anyone can help me my giving me the lowdown or idiots guide on this - I will be most greateful.
@Butuz: Replication is what you want. You can do scheduled replication and (IIRC) asynchronous replication which is instant-ish.
Did you buy through Cutter and are you on their forums? I only ask because I just asked an almost identical question on there a couple of days ago!
Replication will copy the data between two SANs on a schedule of your choosing. I'm not sure how well this will handle data on running VMs.
Replication will transfer the data and metadata in a project and its component shares either at discrete, point in time snapshots or continuously. Discrete replication can be initiated manually or occur on a schedule of your own creation. With continuous replication, data is streamed asynchronously to the remote appliance as it's modified locally at the granularity of storage transactions to ensure data consistency. In both cases, data transmitted between appliances is encrypted using SSL. A project replicated on another appliance is an exact copy of that local project. Every share, share property, snapshot, and configuration setting is replicated.
Snapshots do just as the name suggest and will 'snapshot' the data giving you an instant full backup. Changed data is written to new blocks, non-changed data is referenced from your snapshot so that a snapshot backup doesn't take up and room until the data has been changed.
A snapshot is a point-in-time copy of a filesystem or LUN. Snapshots can be created manually or by setting up an automatic schedule. Snapshots initially consume no additional space, but as the active share changes, previously unreferenced blocks will be kept as part of the last snapshot. Over time, the last snapshot will take up additional space, with a maximum equivalent to the size of the filesystem at the time the snapshot was taken.
I don't think either of these technologies will give you the instant failover you want, for that you need clustering which unfortunately isn't supported on the 7110. Replication will give you failover ability but I think the actual 'activation' of the backup machine would need to be done manually.
The Sun Storage 7000 series Unified Storage System supports cooperative clustering of appliances. This strategy can be part of an integrated approach to availability enhancement that may also include client-side load balancing, proper site planning, proactive and reactive maintenance and repair, and the single-appliance hardware redundancy built into all Sun Storage 7000 series appliances. Because the clustering feature relies on shared access to storage resources, it is available only on the Sun Storage 7310 and 7410. You will be unable to configure clustering on other appliance models, or if the two heads are not of the same model.
I plan to cluster two 7410's across the site next summer to do what you're talking about.
I'll be interested to know how you get on with this. I'm hoping that we'll be able to do this with a currrent 2Tb version to a 4Tb version (which we'll buy soon). I'd like to have all our VM's on the current 2Tb box and mirror this to the 4Tb box, we would then use the extra 2Tb on the 4Tb unit for data. Basically the aim is to provide redundancy for the VM's worst case we can move the data to another server temprarily.
Thanks for the quick replies!!
Sounds like replication is what I need. Yes I to am very interested in how replication will work on live VM's? Will I have to shut down all my VM's in order to perform a "replication"? How does it work on VM's?! I think I'll start off with a schedule of replication each night and see how that goes - if it works well I may try continuous replication!
To be honest I didn't expect automatic failover and will be happy to manually fail over to the other san if one should god forbid fail. Even with manual failovers - this is going to give us a level of data protection waaaaay beyond what we had previously as I will be combing the SAN replication with anormal disk to tape backup of all the VM's.
Just updating the firmware on both SANS!
Last edited by Butuz; 12th November 2009 at 12:05 PM.
Nice one Ric
- Clustron card requires serial connections
- SAS cables don't extend well over 10meters.
Replication is the only way forward for multiple computer rooms with the S7000. As with most replication technologies and ESX, VM's have to recovery manually with scripts or use SRM.
Duke (13th November 2009)
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