Dear all, Thanks for the crew creating HowtoForge and ISPConfig. Great resources and software! Now coming my question. I have an ISPConfig 2 server running on Fedora 6. As the rpm repository of Fedora 6 is not updated anymore, I'm planning to migrate the data to a new server. I first set up a CentOS 5.3 server on a single 320G SATA hardisk. After successful installation, I plug in a second 320G harddisk and turn the system to software RAID 1 configuration with the following guide: http://www.howtoforge.net/software-raid1-grub-boot-fedora-8 The synchronization of both harddisks takes more than 30 hours to finish. ( 'cat /proc/mdstat' show that the sync speed is around 3Mb/s ) Then I connect the new server and the old server with a giga-switch. The data of the old server is made into several tar.gz files. Each tar.gz file is around 1G in size. I put the tar.gz files in a web-accessiable folder. On the new server, I start wget to get the tar.gz files from the old server using HTTP protocol. When I wget a 1G file, it starts download very fast for the first several hundred Megs. The first 40% of the file is transferred at 300Mb/s. But then it drops to 300Kb/s for the remaining 60%. (shown by the wget progress bar) 300Kb/s speed for internal giga-network seems not acceptable. I don't if it is the WRITE limit of the my RAID 1 system? This makes me hestitate now to switch the old server to a new one. I search from internet that software RAID-1 drops about 10-20% in read/write performance. Is there any method to optimize the RAID-1 performance?? Thanks in advance.
I put my home directory on raid 1 (w/ sata drives) a month or so ago... Here's write speed - Code: $ time dd if=/dev/zero of=afile bs=1024 count=1000000 1000000+0 records in 1000000+0 records out 1024000000 bytes (1.0 GB) copied, 22.0697 s, 46.4 MB/s real 0m22.115s user 0m0.240s sys 0m6.316s Here's reading from raid1 and writing to a plain ol' SATA drive - Code: $ time dd if=afile of=/oldhome/me/afile 2000000+0 records in 2000000+0 records out 1024000000 bytes (1.0 GB) copied, 36.9429 s, 27.7 MB/s real 0m37.283s user 0m0.820s sys 0m11.637s And here's reading from raid1 and writing to ram (/dev/shm) Code: $ time dd if=afile of=/dev/shm/afile 2000000+0 records in 2000000+0 records out 1024000000 bytes (1.0 GB) copied, 21.5813 s, 47.4 MB/s real 0m21.584s user 0m0.796s sys 0m6.576s So it looks like the slow spot in my system is the plain 'ol SATA drive - reading and writing to/from my raid1 is faster by about 2x. HTH
