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Mar
16
comment Interrupted apt-get upgrade - Now won't run again
Oops sorry, typo. I did an update, but it was the upgrade that got interupted, and which I'm dubious about now. (will correct in question)
Jan
23
comment What is causing `skb rides the rocket` errors?
OK thanks. There's also another bug tracker page here for the same issue. Interestingly one user reports that disabling sg did not resolve the issue for him. bugs.launchpad.net/ubuntu/+source/linux/+bug/1317811
Jan
5
comment What is causing `skb rides the rocket` errors?
Thanks Jason. According to man, sg off disables scatter-gather - Wouldn't gso or tso be the correct options for disabling packet segmentation? How has this setting worked out for you so far? Any re-occurrences of this issue?
Dec
13
comment NFS share problems - RPC: fragment too large: xxxxx
@Tigran Debian 6
Nov
24
comment Is a 'high' IO rate healthy?
6000 ops/sec does seem high if you don't know what's causing it. Do you have daily backup? It might be that, or some other batch operation.
Nov
24
comment Is a 'high' IO rate healthy?
It's not 6557 operations in two hours, it's an average of 6557 ops per second over the last two hours. From the Linode manager: Average Disk IO ops/sec over 2 hours exceeding this value triggers this alert.
Nov
24
comment Where to start with diagnosis of dropped network connectivity on Debian?
Thanks. There are definitely no problematic gateways involved, as I have multiple servers on the same subnet (1 hop away from each other), and they cannot communicate with the problematic server when this problem occurs. So from your list I assume we can rule out gateway and network issues. That leaves VM->Host issues. Regarding DHCP, from our VM's point of view we are not using DHCP, but rather have a static IP. How these IPs are allocated by the host though I don't know - I suppose something similar to a DHCP lease could be used?
Nov
24
comment Where to start with diagnosis of dropped network connectivity on Debian?
@PaulHaldane - the only entries in messages around that time are from the reboot I did to fix it - nothing from the problem itself.
Nov
23
comment Where to start with diagnosis of dropped network connectivity on Debian?
These are virtual servers servers are hosted with a VPS provider, so the physical layer is not accessible to me. Also since this has happened on multiple servers, it's unlikely to be an NIC fault or cable etc.
Nov
5
comment Ulimit file descriptor limits not being applied for particular process
Thanks. It uses --chuid redis:redis on start-stop-daemon. I've added the ulimit to the startup script now.
Nov
5
comment Ulimit file descriptor limits not being applied for particular process
Great summary Kannan! I've now gone ahead and added the ulimit to the startup script. It's a pity there is no way of just setting the limit for the user which will work with deamonised processes (as we have multiple startup scripts), but this works. Thank you!
Nov
4
comment How to check current TCP Congestion Window on Linux?
Ah, indeed it was 10 :)
Nov
4
comment How to check current TCP Congestion Window on Linux?
Ok thanks - I'll try to get the source, although this is a custom build for a Xen VPS. A pity it's not exposed to the users. Thanks for providing a definitive answer though.
Nov
4
comment Ulimit file descriptor limits not being applied for particular process
Thanks. I suspected that wasn't quite right. The process is being started this line in an init.d script : if start-stop-daemon --start --quiet --umask 007 --pidfile $PIDFILE --chuid redis:redis --exec $DAEMON -- $DAEMON_ARGS. Which pam would be appropriate in this case?
Nov
4
comment Ulimit file descriptor limits not being applied for particular process
Thanks - I'll consider raising the fs.file-max value then. Regarding pam - I believe we are using this (I've added some extra config to the question). I'm not really sure I understand PAM though, as our settings seem to be relate to SSH, which is not used by this user. Is there any other file I need to configure? I could always put a ulimit setting in the init scripts for redis, but would rather not have to do this.
Nov
4
comment How to check current TCP Congestion Window on Linux?
Thanks. Still would like to be able to verify though.
Nov
4
comment How to check current TCP Congestion Window on Linux?
Yes, that only shows the value if you have changed it yourself unfortunately. I'm looking for a way of finding the current value regardless of whether or not it was changed.
Nov
4
comment linux initcwnd and initrwnd via /etc/sysctl.conf
What if its a different interface that you want to change the setting of, other than the default one?
Nov
3
comment Recommended TCP keepalive settings for a busy server
Hmm, not sure - I'll look into that, thanks!
Nov
3
comment Recommended TCP keepalive settings for a busy server
Redis holds all of its data in memory (we don't even have disk snapshotting enabled). Average response times from both servers are in the milliseconds. Yeah, there must be something odd going on, but not sure what yet.