Open Source Highly Available Storage Solutions? 46
Gunfighter asks: "I run a small data center for one of my customers, but they're constantly filling up different hard drives on different servers and then shuffling the data back and forth. At their current level of business, they can't afford to invest in a Storage Area Network of any sort, so they want to spread the load of their data storage needs across their existing servers, like Google does. The only software packages I've found that do this seamlessly are Lustre and NFS. The problem with Lustre is that it has a single metadata server unless you configure fail-over, and NFS isn't redundant at all and can be a nightmare to manage. The only thing I've found that even comes close is Starfish. While it looks promising, I'm wondering if anyone else has found a reliable solution that is as easy to set up and manage? Eventually, they would like to be able to scale from their current storage usage levels (~2TB) to several hundred terabytes once the operation goes into full production."
Entry level SAN? (Score:5, Insightful)
I wrongly implemented HA system will have less uptime than a 499US$ Dell with a single ATA drive.
Entry level SANs using iSCSI are available at quite affordable prices. Look at HPs and IBMs (e.G. the DS300). Even the entry models allow you to use MPIO.
Re:On a normal hardware you can (Score:2, Insightful)
Basically you setup two similar systems (well they don't have to be, but it helps), they get a direct connection between the two, as well as the normal network connections. For this to work well, it is also assumed that you have a SAN setup with the data volumes that you want to share out being available to both servers. If one system goes down, the other takes over all the services that are needed to do what the other was handling (i.e. for instance if you are doing NFS shares, the disk groups that hold the volume are first brought under control by the system, then the volumes are mounted, once the volumes are mounted the virtual IP address used for the hostname sharing that data is configured, then the volumes are shared out. All clients actually see the information through the virtual IP address/DNS name, so if a server fails, the clients will only see a hickup in their connection to the data areas during the time it takes for the other server to take control of the disks and setup the virtual address).
Now, you would also what other things like redundant SAN storage, using storage arrays that support multiple paths or possibly even mirroring between multiple arrays through software like Veritas Disk Suite.
Again, this is well above the mirrored disks in a single server. The poster wants full redundancy in services. Your mirror only fixes a few disk failures, not a network subnet outage, a fibre switch failing, a motherboard failing, a fibre card dieing, etc., etc., etc.... In other words there is a LOT that needs to be in place to get real high availability. A mirror won't cut it.
Rethink your drink (Score:5, Insightful)
Then you can start looking at solutions. 'Optimal File System' can mean many things to many people, and everyone here is going to have a different viewpoint. You need to decide what features of a file system makes it optimal for you. Then you can go looking for a solution.
Re:Entry level SAN? (Score:3, Insightful)
They need to accept that this ain't going to happen, and what they need to do is put in a solution for now and plan for a different solution when they go into production and presumably have the money.
However one has to wonder if there current storage requirements are a messily 2TB why the heck do they need more than one server, unless it is a second for failover.