Note: "permalinks" may not be as permanent as we would like,
direct links of old sources may well be a few messages off.
On 1/5/2011 12:49 PM, Digimer wrote: > On 01/05/2011 11:48 AM, J wrote: >> Hello, >> >> This is my first go at setting up any HA services, so I wanted to see if >> anyone on the list had a similar setup or any recommendations on doing >> this better using drbd. >> >> I'm setting up 2 servers with 2 application services on them. One >> application service is postgresql database (about 5GB of data in >> database). The other is custom software that does a lot of file-based >> I/O (about 15GB of files) with a custom TCP server in front of it. >> >> My idea is to have one server being the master for the custom software >> and the other being the master >> for the postgresql database. The other server will be a stand by for the >> other service. Both will run run ubuntu 10.04 LTS and be connected by 2 >> cat6 1Gb cables. >> >> This will hopefully distribute the load, as I am worried about the >> postgresql clobbering the custom software (which requires very high >> responsiveness). >> >> So is setting up 2 brbd's in opposite configurations on 2 hosts a good >> idea? I'm mostly worried about >> performance and the headache of admin if the links go down. 2 cases of >> split brain on 2 boxes >> doesn't sound fun at all. >> >> Thanks! >> J > If you are using platter-based HDDs, then I'd strongly recommend > creating two separate resources on two separate HDD(s). This way you > won't suffer I/O penalties with the read/write heads flying back and forth. > > Give your relatively small storage requirements though, I'd even more > highly recommend SSDs providing that the write-cycle limit is within > reason. In this setup, then you should have no trouble running it all on > one resource as there are no heads to flog. > > In any case, be sure to have (at least) RAID 1 on each node backing the > DRBD devices to help minimize downtime. Drives fail fairly frequently... > software RAID 1 is an inexpensive route to much better uptime. :) > > Thanks for the recommendation. I agree, I think that SSD's will be a great solution and I'll put in for 4 256GB ones *sweet*. I've still got a lot of things to figure out, so I'm sure I'll be back. Thanks for your help! J