Les Mikesell wrote: > Evren Yurtesen wrote: > >>> Server info: >>> HP DL380 G4 >>> debian sarge >>> dual processor 3.2ghz xeon >>> 2GB Ram >>> 5x10k rpm scsi disks, raid5 >>> 128MB battery backed cache (50/50 r/w) >>> ext3 filesystems >>> >>> brien >> >> You are distributing the reads and writes on 5 disks here. Dont you >> think that 2.40mb/s is a little bit slow compared to the horsepower >> you have? > > Raid5 doesn't distribute disk activity - it puts the drives in lockstep > and is slower than a single drive, especially on small writes where it > has to do extra reads to re-compute parity on the existing data.
I am confused, when a write is done the data is distributed in the disks depending on the stripe size you are using. When you start reading the file, you are reading from 5 different disks. So you get way better performance for sure on reads. Agreed, writes might be slower depending on the raid controller, amount of cache it has etc. but my problem here is the reads. In my machine BackupPC server is working slow even when it is backing up a very small amount of files. >> If you scale it down to my system, I think 1/10 performance is normal... > > Its the RAM and disk cache that makes this system work. > Agreed, I will add more RAM and report the results. Thanks, Evren ------------------------------------------------------------------------- Take Surveys. Earn Cash. Influence the Future of IT Join SourceForge.net's Techsay panel and you'll get the chance to share your opinions on IT & business topics through brief surveys-and earn cash http://www.techsay.com/default.php?page=join.php&p=sourceforge&CID=DEVDEV _______________________________________________ BackupPC-users mailing list BackupPC-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/backuppc-users http://backuppc.sourceforge.net/
