On Fri, May 02, 2008 at 04:40:04PM -0500, Chris Baker wrote: > I'm considering a new backup server and am wondering what hardware I need > for it. I would like to get one with two 100 Mb network cards so they can be > teamed. (Gb cards are useless as all our switches are 100 Mb.) I'm also > looking at getting some SATA drives and going with RAID 5.
Go for RAID10. BackupPC's accesses data very randomly because of the hashing-pooling scheme. It also creates a lot of directories and small files, so get very fast drives (with low seek times, throughput shouldn't be an issue). > I'm also going to divide the full backups into five groups. Some machines > will have full backups on Monday, some on Tuesday, etc. > > BackupPC actually recommends software RAID over hardware RAID. Please let me > know what you think. Hm, the main reason for this might be that the OS is able to optimize disk access better with SW-RAID. With HW-RAID, the OS only sees a huge block device, it doesn't know of the individual disks nor stripe size etc. of the RAID container. If you create a partition on a RAID5, you might end up with the partition starting at the middle of a stripe. All file system blocks will get "misaligned" and a lot more disk activity is needed, especially for writing. With SW-RAID, the OS knows about the hard disks and does the striping etc. itself. So you may safely create a partition, add it to a SW RAID, add it to LVM, create logical volumes and be assured that the logical volume is nicely aligned with the RAID's stripe size. My advice: Take your existing pool and perform some benchmarks! I'd like to do it myself since I've got severe performance problems with my server and I'm not yet sure what's the cause of all this. Unfortunately, I don't have a spare backup server to play with. :-( > Once our new backup server is in place and backing up everyone, I would also > like to back up the BackupPC server to tape (probably LTO-4) or an external > hard drive for off-site storage. I have also read that there could be issues > with this. I am probably just going to do one full backup to media per week. > I would also love to hear whatever recommendations anyone has for this. I wrote myself a shell script which get's called by my Bacula job. It creates TAR files for servers which haven't been saved to tape for some time. Because of the heavy I/O and performance issues, it only manages to tape-backup a few servers each day (about 3-5). > I'm still wondering if such a backup plan is even possible. We have a lot of > data. Generally speaking: BackupPC's performance is mostly affected by the number of files, not by their size! If you've got a lot of files and directories, performance will drop. HTH, Tino. -- „What we resist, persists.” (Zen saying) www.craniosacralzentrum.de www.forteego.de ------------------------------------------------------------------------- This SF.net email is sponsored by the 2008 JavaOne(SM) Conference Don't miss this year's exciting event. There's still time to save $100. Use priority code J8TL2D2. http://ad.doubleclick.net/clk;198757673;13503038;p?http://java.sun.com/javaone _______________________________________________ BackupPC-users mailing list BackupPC-users@lists.sourceforge.net List: https://lists.sourceforge.net/lists/listinfo/backuppc-users Wiki: http://backuppc.wiki.sourceforge.net Project: http://backuppc.sourceforge.net/
