Hello Yall, I'm starting to play with DRBD to build a small (2-node) failsafe cluster here.
The problem is, although DRBD starts really quickly with my SATA drive, with the MD (software RAID) device it's REALLY slow. It's like: Dec 7 18:41:12 mail0 drbd0: resync bitmap: bits=87603792 words=2737620 Dec 7 18:41:12 mail0 drbd0: size = 334 GB (350415168 KB) Dec 7 18:44:49 mail0 drbd0: 0 KB marked out-of-sync by on disk bit-map. Dec 7 18:44:50 mail0 drbd1: resync bitmap: bits=50975584 words=1592988 Dec 7 18:44:50 mail0 drbd1: size = 194 GB (203902336 KB) Dec 7 18:44:51 mail0 drbd1: 0 KB marked out-of-sync by on disk bit-map. DRBD0 is built over /dev/md4 that is built over two SATA disks. While this load process is running, I tried a dstat -df to see what disk activity I'm having and I found out that DRBD was reading at 100Kbps. On the other server it happens exactly otherwise. That's because the DRBD0 is on the SATA and DRBD1 is on the MD4: Dec 7 18:41:12 www0 drbd0: resync bitmap: bits=87603792 words=2737620 Dec 7 18:41:12 www0 drbd0: size = 334 GB (350415168 KB) Dec 7 18:41:14 www0 drbd0: 0 KB marked out-of-sync by on disk bit-map. Dec 7 18:41:14 www0 drbd1: resync bitmap: bits=50975584 words=1592988 Dec 7 18:41:14 www0 drbd1: size = 194 GB (203902336 KB) Dec 7 18:43:19 www0 drbd1: 0 KB marked out-of-sync by on disk bit-map. And that proves that it is a problem with the DRBD-SoftwareRAID couple. Versions: Kernel: 2.6.18-gentoo-r3 DRBD: 0.7.22 (although it's not on Portage, it's the only one that works with kernel 2.6.18). Thank you all. Best regards, Daniel Colchete -- gentoo-cluster@gentoo.org mailing list
