Server Redundancy for a Small Business?

SadPenguin asks: "I am currently working for a small company of about 15 people each with one to two workstation/laptop machines a piece. We are looking for a new server solution, as our last one crashed, and lacking any server redundancy, we nearly lost all of our data since our last backup (it was only a few days, but an important few). What the kind of server (and redundancy) solution would be appropriate for a company of my size? Most advertisements are for large scale enterprise serving solutions, but these are costly and excessive for my situation. I'm sure that there is a simple Redundant Server technology out there that is a bit less costly, but won't result in any downtime in the event of a motherboard component failing (like we faced this time when our mysterious surface soldered VRM failed). So what do you use? What should I use?"

My small company solution

[Bistronaut]

I work for a small company that only has three full-time employees (including me). I use two Debian boxes (cheap-o machines that are just retired desktops with some big cheap IDE hard drives in them) running Samba. I use the rsync mirroring technique I found here [mikerubel.org].

One box is the "live" server and the other mirrors the live server every night. If the main server dies (which happened once - power supply failure), I can "promote" the backup server by changing one line in its Samba configuration. As a bonus, the backup server keeps "snapshots" back a week or two.

Simple, cheap answers for redundancy...

[stienman]

I do three types of redundancy/backup at my sites:

* Mirrored Raid in all servers
* A regular workstation with a good, large had drive that copies the server data to itself nightly
* A DVD-RW backup made nightly on yet another workstation, with at least one off site - 5 discs, one each weeknight, replaced a few times a year.

In most cases the server RAID (cheap ATA promise controllers) takes care of 90% of the problems - only one HD goes bad at a time, lightning strikes rarely take out the hard drives at all, nevermind both hard drives, etc. Even if it dies it's unlikely that the problem affected the HD backup on the other workstation, and it definitely didn't affect the cd-rw.

However, whenever you get a catastrophic failure in any component in the server, replace the entire thing. If the MB or power supply fails, copy the data to new hard drives, and use the old ones in less critical applications, etc.

Much cheaper than an 'enterprise' solution, and it should be because your application doesn't require such a solution. Use large tape drives in place of the dvd-rw if you must back up a huge amount of data on a nightly basis.

This sort of solution is very tolerant of cheap hardware, so replacing the server later may not be such a major cost.

-Adam

Re:A few recommendations.

[jmt9581]

These are all very good solutions. More ideas include high availability network stuff such as UCARP [ucarp.org] or HA-Linux. Many of these depend on specific details of your setup, these recommendations are definitely biased towards Unix/Linux systems. In my experience, having backup systems for your important is a crucial idea, having employee downtime as a result of system failure is a nightmare for any company, especially a small business.

A mysteriously soldered VRM sounds a bit odd, you might think about going with a rock-solid hardware platform if/when you upgrade your current infrastructure. I've had great success with a Sun E450 for the last two years, it's a rock-solid piece of equipment that's required absolutely no hardware maintenance.

It's difficult to give you more concrete recommendations without knowing more about your setup. Things like hot database backups can be tricky, especially if your IT staff isn't experienced in database backup solutions. You might find value in discussing some ideas with a consulting company. The parent post seems to know a lot about this, and there are certainly other companies out there [biosysadmin.com]. :P

Best of luck to you.

5000$ or less and you are in business

[nenam]

We just finished building a 2.5 TB (terabyte) server for less than 5000$. You could probably spend even less than that since we spend about 1000$ on two fiberoptic cards. We have 2 6 chanel 3ware RAID cards and 12 250 133ATA Maxtors hooked up to a 520 watt powersupply plus another 520 watt power supply acting as redudant power(we did that mod inhouse). 2.5 TB is probably more than you guys will need unless you are doing some advertising or something like that... so you could probably go for 1 TB, which will cut your costs down even more. So all in all you could probably get it done in about 3000$ not too shabby for 16 ppl. Our server backs up my whole college.

as a refreshing alternative...

[BigGerman]

.. get people into the habit of running CVS or Subversion client on "their documents" folders. Tortoise integrates right into Windows explorer. Advantages: file versioning, ability to work off line and still sync with the server later, etc.
if people actually work with plain text docs, they would love how CVS,etc will merge multiple users' changes.
Of course you would back up your CVS server but in case of a crash, chances are that very important file can be found on the desktop of the user who edited it the last time. Much better than relying on a network drive and then it is just not there.

Re:RAID 5?

[pbox]

I need to point out that your selection criteria should include multiple firewire ports, and firewire controllers on both the drive and ant the server end. Should add only marginal cost to your setup.

I have a maxtor FW single HDD backup solution, but I definitely would not recommend that particular one for constant on situation (for lack of ventillation). It seems that when the drive does the temp calibration the FW insterface hiccups, and the ongoing transfer gets interupted. All is well after diconnection and reconnection. I only notice it when I am doing unison on very large directories (30+GB), but if you would serve files off of it, you might be getting into trouble as well.

Other issue with FW is bandwitdh. I am getting about 40-50MBps which is enough for sustained transfers, but the drive would be capable to 100MBps in burst (short files cached on the drive). This might be detrement to the file server performance.

I do have to say that I quite like the idea of having 4-6 external FW (or better FW800) disks hooked up, and running a virtual RAID5. This way the failed disk would be very easily hot-swapped. And might even be much cheaper than having hot-swap support backplane/chassy/server.

Re:Daily backups

[itwerx]

Heh, touche'! :)
But I've been in the industry for over fifteen years with thousands of clients and the last time I had a hardware raid do that was almost six years ago.
Software raid on the other hand inevitably takes more time/effot/energy to recover from failures (especially if you're so foolish as to use what's provided by Win2K!).
Hardware hot-swap RAID is easy, just change drives and nobody knows anything happened.
Software RAID usually requires at least a reboot if not fiddling with system files.
Ergo, the labor cost of software raid usually ends up being more than the component cost of hardware raid.
Not to mention the performance difference between software and hardware raid is like night and day! (Just remember to get the little battery pack option if you decide to use write cache on the raid card :).

Re:My small company solution

[questforme]

I use the rsync solution for my home computer(although to an external hard drive, not a second computer) and love it, as a matter of fact I had an unplanned test last night and it rebooted without a hitch.

If you really wanted to save some more money you could use an external drive to rsync to although you would have to get your server fixed before you could copy the rysnc'd files back over.