Hi all, I looked at fyodor a little more closely today when it was doing an rsnapshot backup. I know that we're getting off of this machine soon, but it has come to a point where performance is really bad during the backup interval (moinmoin pages don't load, and even typing "w" take a good 10 seconds to return).
I started looking at the problem by checking vmstat 1. This showed up to 18 blocked processes during one snapshot. Then, I looked at iostat to see where the highest activity was. Tons of reads and writes to /dev/hda9 and /dev/hdb9, which are the disk partitions that rsnapshot points to, through the RAID 1 configuration. I am presuming that this is the disk activity that is blocking other processes. If we are going to be on fyodor for even a few weeks, I would like to try and resolve this if it is easy enough to do. One thing that I was thinking of trying that may lessen the side-effects of this backup processes is to somehow get it to not write through the software RAID setup. Basically, we would have to get an area of space that is sufficient for our backups, then point rsnapshot to this partition. Would this be possible while the system is running? I have a feeling that it would take care of the blocked processes that I was noticing, and really buy us some time that we could be comfortable on fyodor while continuing to increase membership. How about other options, such as pointing the rsnapshot backups to an off-site system? I have a machine on a DSL connection that may work, short-term for this purpose. Another possibility may be to throw another hard drive in the chassis, if we have the space, and using that for the rsnapshot writes. This should be sufficient to make our machine usable during backup periods. Probably it would cost us a couple of hundred dollars to get interserver to do it, but if we can stay on the current setup for a few more months it might be worth it. Justin _______________________________________________ HCoop-SysAdmin mailing list [EMAIL PROTECTED] http://hcoop.net/cgi-bin/mailman/listinfo/hcoop-sysadmin
