Messages in this thread | | | From | Hartmut Manz <> | Date | Thu, 7 Dec 2006 14:28:44 +0100 | Subject | SCSI Controler SCRU32 becomes realy slow on the latest kernels |
| |
I am using here 2 machines with the ICP Vortex SCSI-Controler SCRU32 for some years now.
After switching one machine from Debian 3.1 (sarge, with Kernel 2.6.8) to the upcoming Debian 4.0 (etch with Kernel 2.6.17 or 2.6.18) I have noticed that my scsi-devices become very slow while there is also a dramatical increase in the sys time needed for I/O operations.
The machine is a dual processor Xeon system (2 * 2.2 GHz) with 2 GB memory. The used scsi drives are seagate R10k and R15k disks.
i.e. reading 1 GB from the first SCSI drive takes about: xen-1:/var/log# time dd if=/dev/sda bs=256k count=4000 of=/dev/null 4000+0 records in 4000+0 records out 1048576000 bytes (1.0 GB) copied, 55.3079 seconds, 19.0 MB/s
real 0m55.361s user 0m0.368s sys 0m49.107s
There are two strange things: 1. The transfer rate is only 19 MB/sec what is very low for this machine. The expected value would be at least 50 MB/sec.
2. the system time is in the same range as the real time and thats realy annoying, on the old kernel the system time for such an operatin was about 7 sec.
Thanks for any help
Hartmut
-- ----------------------------------------------------------------------------- Hartmut Manz WWW: http://www.intes.de INTES GmbH Phone: +49-711-78499-29 Schulze-Delitzsch-Str. 16 Fax: +49-711-78499-10 D-70565 Stuttgart E-mail: manz@intes.de Gott spricht: Ich lasse dich nicht fallen und verlasse dich nicht. ------------------------------------------------------ Josua 1, 5b --------- - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
| |