On 10/2/07, Tony Nelson <[EMAIL PROTECTED]> wrote: > My first decision point is potentially the easiest. I thought rather > than buying one huge backup server and trying to backup all 32 hosts, it > might be smarter to buy 2 (or more) smaller machines and splitting up > the load. I would think that multiple machines might cost a little more > up front, but I'm hoping I would get better throughput that way.
How many machines you buy and how big of a machine you buy will depend on the size of your backups and what your backup window of your largest backups are. If most of your hosts back up fairly quickly, but you have a handful of hosts with a lot of data/files and not a lot of time to get the backup done, you may need a machine with faster CPUs and more spindles to get the job done. If you identify the problematic backups using your current machine and get some performance metrics as well as what your performance targets are, that will help identify the type of hardware you should be looking at. Don't forget the overhead of managing an additional machine as well. > The second decision point would be vendor. Currently we buy most of our > hardware from Dell. I'm fine with Dell unless there is vendor out there > that sells boxes for a reasonable price that are hands down better for > the application (possibly because of RAID controller cards). Dell is what we usually use when purchasing hardware. Sometimes we use HP. Vendor isn't too important here, what's most important for BackupPC is disk speed, total memory and CPU speed and cores. > I've already read a lot of the discussion on RAID configurations in the > list. I've ruled out RAID 5. RAID 10 looks nice, but really expensive. > A simple mirror seems pointless, and a simple stripe seems like too > much of a single point of failure. If I were to do RAID 10, with say > 500GB SATA drives, would a single raid controller suffice, or does it > really pay to get 2? As others mentioned, there isn't any reason to get more than one controller. If you were doing a lot of streaming reads/writes at high bandwidth with enough disks, splitting onto multiple controllers can help. But with BackupPCs workload of lots of small reads and writes, it's not critical. RAID10 while expensive, gets you the highest performance and highest reliability in the face of disk failures. How many disks per machine are you looking at? If RAID10, that means at least 4. Our fastest BackupPC servers use 6 15k SCSI disks. Remember that with the high-seek activity BackupPC presents, high spindle speeds are important for fast backups. As a general guideline, we look to spec a machine with 1 CPU and 2 disks for every 2 concurrent local net backups that we want to run at full speed. This will be overkill if the clients are over a slow network and/or if the CPU/disk speed on the clients are slower than the servers. Also take into consideration the power requirements of the system(s). Since your backupc system will likely be idle 90% of the time, AMD systems will usually have much lower idle power requirements. But the pricing of quad-core Intel systems is very good right now. If you were to build a single system backing up 32 clients that have ~10gb average to back up (seeing your current host summary page would help), I would recommend something with 4 cores and 8 disks in a RAID10 and 2-4+GB of RAM. Cut that in half if going for multiple smaller systems. This should let you back up 4+ clients in parallel as fast as they can go. Get 10k or 15k disks if you can, but the price premium may be too much depending on what your total storage requirements are. But given that your current system is a dual CPU system with 6 250GB disks in RAID 5, I really suspect that if you could simply reconfigure your existing system into a RAID10 configuration (assuming going from 1.25TB to 750GB is still enough disk space) would be a substantial improvement. In fact, if you are going the multiple system approach, you may start off with one new small/medium system (2-4 cores, 4-6 disks) to get you to where you can reconfigure your existing system. -Dave ------------------------------------------------------------------------- This SF.net email is sponsored by: Microsoft Defy all challenges. Microsoft(R) Visual Studio 2005. http://clk.atdmt.com/MRT/go/vse0120000070mrt/direct/01/ _______________________________________________ BackupPC-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/backuppc-users http://backuppc.sourceforge.net/
