Tag Archives: NFS

Update

Posted on by

Been a while since my last post.

Today I tried out my new mountain bike. I cycled to M&D’s and back, it wasn’t too bad despite the hills, only took 10mins. I do seem to be suffering now though – inhaling all the cold air has screwed with my lungs it seems.

Dad and I have been collecting free firewood from a neighbour, which is nice (although very hard work lugging around) but now we’re itching a bit, so hopefully don’t have poison oak or something. On the way there today we decided to take a shortcut and I ended up getting stuck in a waterlogged ditch, luckily right next to a tractor which pulled us out. I’ll never moan about slow tractors on the road again!

M&D got a new DivX player, its got a USB port so I’ve ordered a couple of 8Gb thumbdrives to try it out with. Its also got a SD card slot, so should be interesting to see if it will play video’s from Mum’s digital camera (as well as obviously the photo’s).

I switched my fileserver to NFSv4, which seems to have improved performance and stability as I’m not getting the “server not responding” errors and Nautilus dying as I was with v3. Its a very different setup though – it has the concept of a root share, and then individual shares beneath it.

Strangely enough MacOSX 10.5 is not supposed to have an NFSv4 client and NFSv4 is not supposed to be backwards compatible, however I can still mount the root share albeit not the individual shares beneath it.

I’m still getting strange speeds though – like NFSv3 took 8mins to transfer 2.7Gb, NFSv4 took 3m30s, NFSv3 on the Mac took 1m30s, SCP took 3m30s and FTP took just 70secs!

I also tried out NIC bonding on my Fedora7 box, you basically setup two GigE cards to round-robin between themselves, appearing as one IP address externally (bit like IPMP on Solaris). It increased my bandwidth from 580-690Mbit/sec to 910-940Mbit/sec – or 112MBytes/sec, and also can cope with you unplugging one of the ethernet cables. I might set it up on my fileserver with a second PCI card.

I tried out Oracle Unbreakable Linux 5.3, which is a shameless ripoff of RHEL 5u3, but not in the free vein of CentOS, it still requires commercial support (a RHN/up2date ripoff) instead of free updates via YUM, and it has a few Oracle-specific patches which either haven’t been accepted upstream or are closed source.

Automount goodness

Posted on by

I’ve just found my favourite piece of software (of the week, at least): Automounter or amd.

Basically it allows you to mount filesystems on demand, so I’ve got it setup on all my Linux boxes now to mount each other’s NFS shares. The extra good bit is that if the NFS server is offline it doesn’t hang your machine on boot (like putting it in /etc/fstab does).

All you need is to install autofs (“yum install autofs”, which i think sets it to start on boot) and create the following two files:

/etc/auto.master :

/media /etc/auto.nfs --timeout=3600 --ghost

That mounts the shares in /media, and tells it to create the directories even if the server is offline, and to unmount them again after and hour if idle.

/etc/auto.nfs :

data5 -fstype=nfs,hard,intr,timeo=10,async,rw 192.168.0.6:/data5

That’s the equivalent of your “mount -t nfs” command (or /etc/fstab entry), it tells it to nfsmount in /media/data5, not to fall over if the server goes offline (although it still does a bit), async for performance, read+write permissions, and the server IP and mountpoint on the end (as in /etc/exports).

What’s extra cool is that when the NFS server boots, it creates disk icons on your desktop (due to the mountpoints being in /media)!

I guess this is similar to how MacOSX does it with its “Directory Utility”. I upgraded the MacMini to OSX 10.5.6 today, doesn’t seem to be anything particulary new/interesting….

Rotten Sunday

Posted on by

I’ve got a cold today, so taking it easy. I’ve watched some films as I don’t feel like doing much, but they’ve all been a bit naff.

Lakeview Terrace, about an arsehole cop who makes the lives of those who live around him a nightmare.

Transporter 3. Pretty good, but I really think its time they broke the mould, as the Transporter films seem to have a recipe:

  • Someone’s daughter gets kidnapped and Frank has to transport her;
  • She’s a pain in the arse, but still falls for Frank;
  • Frank’s client tries to kill him;
  • Frank’s house gets destroyed;
  • Frank has a fight scene or two where he kicks the arses of a dozen or so guys;
  • Lots of fast driving scenes – although this time it was an Audi, not a Mercedes.

At least it was better than Transporter 2 I guess, back to the Transporter 1 roots.

Finally I watched Ghost Town, which could be described as a comedy version of Ghost or Sixth Sense – some guy can see ghosts and has to help them, whilst falling in love. The problem was it wasn’t very funny, and the romance bit featured more than the ghosts bit.

I’ve also been playing with my LAN bandwidth again today. I’ve been testing three Linux boxes with gigabit cards and can get up to about 90MBytes/s, or around 700Mbits/sec using iperf, which is not bad, although I never see that kind of speed when transferring files over rsync, NFS or sftp. I also had another go at enabling jumbo frames with an MTU of 7168, but it still doesn’t work. I guess disk is the bottleneck as only the 1Tb drive in my Core2Quad can manage 120Mbps reads, the 250/500Gb drives are maxed out at about 70Mbps, and probably less for write operations. Maybe I’ll try RAID striping a couple of the 250Gb’s in my Pentium4 sometime.

Update: just found a really useful Firefox plugin called Firebug, it lets you inspect the HTML/CSS/Javascript of any element on a web page – and even change them. Very handy for when you’re trying to modify a bit of a WordPress stylesheet but can’t figure out if the element is an h2 or a sidebar.caption

NFS performance

Posted on by

I noticed when transferring files from the new Core2Quad to the fileserver that there seems to be a big burst of file transfer (like 500Mb in a couple of seconds) and then the remaining 200Mb or whatever seems to take forever – so much so that the windows grey out and Nautilus becomes unresponsive. I’ve got a feeling that this is a Compiz or Fedora9 issue, as it doesn’t present itself with Fedora7 – well some unresponsiveness maybe, but that’s probably due to the not-that-great drives or SATA controller in the fileserver. Hell it could be that the Quad is so much faster than the fileserver that it is waiting for it to catchup!

Anyway I’ve been playing around with NFS settings and have set the async bit in /etc/exports, which seems to give a few percent performance increase (copying a 700Mb file takes 50-ish seconds instead of ~1m5s with sync set). None of the /etc/fstab rsize or wsize settings made any difference. I guess that’s still not bad as it works out at 112Mbps – which includes the write time for a 700Mb file, not just the network speed.

I also tried enabling jumbo frames again on my ethernet cards – well that didn’t work, so I tried a piece of crossover cable in case it was my switches or routing setup, but that made no difference. I even tried using the Intel e1000 card with 9k frames instead of the Realtek r8169 cards with 7k frames – still no go. So I’ve come to the conclusion that MTU>1500 just doesn’t work on Linux 2.6 kernels!