Note: "permalinks" may not be as permanent as we would like,
direct links of old sources may well be a few messages off.
Hello List, I have a strange problem with DRBD on my FSC 64Bit servers. Here is what I use (I tried Debian Stable standard kernel and drbd module source at the beginning. Makes no difference) Debian Stable drbd0.7-utils drbd-0.7.24 kernel module Linux 2.6.21-2-amd64 One server has two CPUs and 4GB RAM, the other one 1 CPU and 2GB RAM. The rest of the hardware is identical. DRBD linked together via cross over. There is a MPT SAS RAID Controller in the system... 05:05.0 SCSI storage controller: LSI Logic / Symbios Logic SAS1068 PCI-X Fusion-MPT SAS (rev 01) At the beginning, I configured a RAID 1 with this controller. It seems well enough supported. My little test: I have a .tar.gz with 2GB, which resulted in 3,5GB not to many large files. On a non DRBD Partition, I needed 4min to unpack this archive. Which is quit bad, but not horrible. I configured DRBD (in the beginning with defaults. Sync rate 50M.). First, everything seems ok. But then I realized the following: While unpacking the test archive, the following happened: - The first ca. 2GB unpacked really fast. Suddenly it gets slower and slower. At the end, I saw a write rate of 2MB/sec and LESS. It took more then 20min (!) to unpack the archive... I didn't believe my eyes. So I tried this and that. Finally I disabled the MPT SAS Raid 1 in the Controller BIOS on both machines. Now it took less then 3min to unpack the test archive. (DRBD alone is faster, then a local MPT SAS RAID 1!) Now I am curious: Is there any special problem with this (or any) RAID controller and DRBD? Perhaps the RAID controller is simply trash and I better use Linux Softraid? Probably its stupid to use a local RAID 1 AND a DRBD Raid 1 in conjunction? Greetings, Felix