hi ya marc On Sat, 15 Oct 2005, Marc Dreher wrote:
> after a recent (data) lossy HD crash I decided to build a software raid > 5 (3 disks)with Debian Sarge (2.6.13 Kernel) to keep that from > happening again :-) 3 disks in raid5 means 1/3 of the total disk space is not usable > Works pretty well but I am not really satsfied with the write > performance (via samba). writing data into raid5 will be slow, since it's writing parts of the same data n-times to each disks reading should be faster ... but not always > When uploading files via samba I get around 6 MB per second. Uploading > to a non-raid disk works at full 100Mbit network throughput (10 MB > p/s). presumably the target disks getting the uploaded files is on the same pc ??? and the obsvervation you're seeing is normal/typical > I have one ATA disk as master on each of the two onboard IDE channels > and the third SATA disk on one of my two SATA ports. odd combo but good to have only 1 disk on each ide cable > I used a chunk size of 64KB with no strides. more parameters to play with > So before having to experiment with all kind of settings I hope that > somebody does have any tips or tuning hints for me? increasing write performance is not ez - you probably can change your nfs read/write transfer sizes to get some improvements - you probably can get "faster" transfers if you compress it before sending it tar zcf - stuff | ( cd /mnt/samba ; tar zxfp - ) > I think with current hard- and software I should at least be able to get > enough write performance to fill up my 100MBit network while uploading :-) 8bits * 10MByte/sec --> 80Mbps .. that's pretty good anything say aroun 70% - 90% of the rated networkwork thruput is good you will need to go to GigE network 8bits * 100MB/sec --> 800Mbps ... good enough for gigE entwork and the disks are rated ( by marketing folks ) at 100MB/sec (120MB/sec) or faster and your new bottleneck will be the disk rotations c ya alvin -- To UNSUBSCRIBE, email to [EMAIL PROTECTED] with a subject of "unsubscribe". Trouble? Contact [EMAIL PROTECTED]