Re: [expert] Copying a file across NFS
On Mon, 28 Jul 2003 19:34:56 -0700 Rob Blomquist <[EMAIL PROTECTED]> wrote: > > > This sounds exactly as you describe... collisions! They are due to a > > number of reasons; but some things to check: > > > > 1. Bypass the hub with a direct (rolled) cable. If this works (check > > collisions in ifconfig), then replace your hub with a switch which > > doesn't suffer from the following... Note: some "hubs" are really > > switches... A real hub is a cheap buffered repeater -- the buffer is > > rather small (acts like an "elastic buffer"); it "snaps" when a > > sending NIC's crystal is out of specs -- the snap results in the hub > > sending a "jam" (collision) back to the sending NIC. Bypassing the > > hub eliminates the hub's elastic buffer. I'm surprised you're able to > > send that much data if this is the problem though... > > Well the hub I use a LinkSys NH-105 connects all the machines on the > network, our DSL router, my Linux box, our File server, and my wife's > laptop. One of mine is a LinkSys EFAH05W, sold as a "hub" (as opposed to the one sold as a "switch"); but it is really a switch. I wanted a real *hub* for net. monitoring purposes; but that's another story. > I have not recently checked my wife's laptop, but the only time that I > see these collisions is between my box and the file server. And yes, I > did get 650Mb to pass after rebooting the server. Are they on both ends, or just between the LinkSys and one of the machines? > > 2. Near end collisions: are your cables direct, or running through > > hookups around the house? Poor connections and not enough twists in > > the pairs or poor cable at the sending end can result in near-end > > collisions due to crosstalk from sending signal back into sender's > > receiver circuitry-- hearing itself. > We just moved, and right now all connections with the hub to machines > are less than 10 feet. So I don't think there is a problem there, but > maybe the hub to FS cable is bad, it has gotten a bit of strain, as I > forget it is only 3 feet long. Near-end collisions have been know to occur on short cables and be resolved with longer cables; but I don't have a specific example as that experience was circa 1991. On the other hand, if near-end coll. are not the problem, and the coll. are only seen on one box, I might be tempted to swap the NICs to see if the problem changes. That said, this is ethernet, and collisions are normal to some extent. I was once doing some tests on a server/router pair and found that there were 30% collisions on a direct 10baseT/CAT5 link -- turned out to be the pseudo-random backoff algorithm in both machines was causing the problems. Both were trying to be aggressive in getting their data on the wire resulting in tons of early colisions. This is something that can't be fixed easily -- low-level driver changes needed -- no idea if that is in the Linux drivers, or in the NIC's logic (probably the latter)... > > > 3. If your NIC is an Intel eepro10, consider trying something else... > > I had this very problem when transferring large files... > > interestingly, the apparently random failures were at exactly the same > > point on any specific file. > > No I run a mixture of 3Com 3C509 and D-Link RTL 8139 using the 8139too > driver. When transfering a particular file, any chance the length of the transfer is always the same...? A long shot; but if so, it would be a problem the kernel folk should hear about... in that case, let me know and I'll dig out my notes... > I will check the cables and the hub as you say, and replace as needed, > upgrading the hub if needed. May be moot... but good luck. > Rob Want to buy your Pack or Services from MandrakeSoft? Go to http://www.mandrakestore.com
Re: [expert] Copying a file across NFS
> This sounds exactly as you describe... collisions! They are due to a > number of reasons; but some things to check: > > 1. Bypass the hub with a direct (rolled) cable. If this works (check > collisions in ifconfig), then replace your hub with a switch which doesn't > suffer from the following... Note: some "hubs" are really switches... A > real hub is a cheap buffered repeater -- the buffer is rather small (acts > like an "elastic buffer"); it "snaps" when a sending NIC's crystal is out > of specs -- the snap results in the hub sending a "jam" (collision) back > to the sending NIC. Bypassing the hub eliminates the hub's elastic > buffer. I'm surprised you're able to send that much data if this is the > problem though... Well the hub I use a LinkSys NH-105 connects all the machines on the network, our DSL router, my Linux box, our File server, and my wife's laptop. I have not recently checked my wife's laptop, but the only time that I see these collisions is between my box and the file server. And yes, I did get 650Mb to pass after rebooting the server. > 2. Near end collisions: are your cables direct, or running through > hookups around the house? Poor connections and not enough twists in the > pairs or poor cable at the sending end can result in near-end collisions > due to crosstalk from sending signal back into sender's receiver circuitry > -- hearing itself. We just moved, and right now all connections with the hub to machines are less than 10 feet. So I don't think there is a problem there, but maybe the hub to FS cable is bad, it has gotten a bit of strain, as I forget it is only 3 feet long. > 3. If your NIC is an Intel eepro10, consider trying something else... I > had this very problem when transferring large files... interestingly, the > apparently random failures were at exactly the same point on any specific > file. No I run a mixture of 3Com 3C509 and D-Link RTL 8139 using the 8139too driver. > 4. If you're using coax, you may have termination problems (no need to > discuss now unless you have coax). Nope, CAT-5e. I will check the cables and the hub as you say, and replace as needed, upgrading the hub if needed. Rob -- Linux: For the people, by the people. Want to buy your Pack or Services from MandrakeSoft? Go to http://www.mandrakestore.com
Re: [expert] Copying a file across NFS
On Sun, 2003-07-27 at 05:11, Pierre Fortin wrote: > On Sat, 26 Jul 2003 21:28:53 -0700 Rob Blomquist > <[EMAIL PROTECTED]> wrote: > > > > > > > > > I am seeing a lot of collisions at my hub and in ifconfig. Is it > > > > > > possible that I have a NIC going bad? Or might there be another > > > > > > reason? I have 8.0 Gb free on the drive recieving the file. > > > Well, I rebooted the server, and it was able to move the 650 Mb without > > choking, but with almost constant errors. I will burn out my orange LED > > on the hub soon if this keeps up. > > > And there don't appear to be any kernel messages about this. > > > > Rob > > This sounds exactly as you describe... collisions! They are due to a > number of reasons; but some things to check: > > 1. Bypass the hub with a direct (rolled) cable. If this works (check > collisions in ifconfig), then replace your hub with a switch which doesn't > suffer from the following... Note: some "hubs" are really switches... A > real hub is a cheap buffered repeater -- the buffer is rather small (acts > like an "elastic buffer"); it "snaps" when a sending NIC's crystal is out > of specs -- the snap results in the hub sending a "jam" (collision) back > to the sending NIC. Bypassing the hub eliminates the hub's elastic > buffer. I'm surprised you're able to send that much data if this is the > problem though... > > 2. Near end collisions: are your cables direct, or running through > hookups around the house? Poor connections and not enough twists in the > pairs or poor cable at the sending end can result in near-end collisions > due to crosstalk from sending signal back into sender's receiver circuitry > -- hearing itself. > > 3. If your NIC is an Intel eepro10, consider trying something else... I > had this very problem when transferring large files... interestingly, the > apparently random failures were at exactly the same point on any specific > file. > > 4. If you're using coax, you may have termination problems (no need to > discuss now unless you have coax). > > This is a start; but the problem is most likely hardware... although, > until it's found *and* fixed, never say: "It can't be ..." :> Pierre, I'd say you probably are right on the money here. I've got or rather had (they were sold for scrap) some 24 port cardinal hubs that where guaranteed to give you collisions like mad. Not when used alone, but when used with each other look out. I only install switches now. Much safer. James Want to buy your Pack or Services from MandrakeSoft? Go to http://www.mandrakestore.com
Re: [expert] Copying a file across NFS
On Sat, 26 Jul 2003 21:28:53 -0700 Rob Blomquist <[EMAIL PROTECTED]> wrote: > > > > > > I am seeing a lot of collisions at my hub and in ifconfig. Is it > > > > > possible that I have a NIC going bad? Or might there be another > > > > > reason? I have 8.0 Gb free on the drive recieving the file. > Well, I rebooted the server, and it was able to move the 650 Mb without > choking, but with almost constant errors. I will burn out my orange LED > on the hub soon if this keeps up. > And there don't appear to be any kernel messages about this. > > Rob This sounds exactly as you describe... collisions! They are due to a number of reasons; but some things to check: 1. Bypass the hub with a direct (rolled) cable. If this works (check collisions in ifconfig), then replace your hub with a switch which doesn't suffer from the following... Note: some "hubs" are really switches... A real hub is a cheap buffered repeater -- the buffer is rather small (acts like an "elastic buffer"); it "snaps" when a sending NIC's crystal is out of specs -- the snap results in the hub sending a "jam" (collision) back to the sending NIC. Bypassing the hub eliminates the hub's elastic buffer. I'm surprised you're able to send that much data if this is the problem though... 2. Near end collisions: are your cables direct, or running through hookups around the house? Poor connections and not enough twists in the pairs or poor cable at the sending end can result in near-end collisions due to crosstalk from sending signal back into sender's receiver circuitry -- hearing itself. 3. If your NIC is an Intel eepro10, consider trying something else... I had this very problem when transferring large files... interestingly, the apparently random failures were at exactly the same point on any specific file. 4. If you're using coax, you may have termination problems (no need to discuss now unless you have coax). This is a start; but the problem is most likely hardware... although, until it's found *and* fixed, never say: "It can't be ..." :> Want to buy your Pack or Services from MandrakeSoft? Go to http://www.mandrakestore.com
Re: [expert] Copying a file across NFS
> > > > I am seeing a lot of collisions at my hub and in ifconfig. Is it > > > > possible that I have a NIC going bad? Or might there be another > > > > reason? I have 8.0 Gb free on the drive recieving the file. > > > > > > Are you having trouble with all files or just the iso's. I think we > > > need to determine if the problem has anything to do with the size of > > > the file. > > > > It is just the isos, I have copied kernel-2.4.24.tar.gz to the same > > directory and its about 30Mb and it moves sucessfully. > > > > Usually the problem crops up when 30-100Mb are copied over. I have had > > 30, 80 and 100 Mb incomplete files on the server when it quits. > > Are you seeing any errors in your logs? what does the exports file of the > server, and the fstab file of the client look like? Well, I rebooted the server, and it was able to move the 650 Mb without choking, but with almost constant errors. I will burn out my orange LED on the hub soon if this keeps up. from fstab on the client: cartman:/mnt/share /home/robbo/share nfs auto,user,rsize=8192,wsize=8192,soft 0 0 from the server: /mnt/share *(rw,no_root_squash) And there don't appear to be any kernel messages about this. Rob -- Linux: For the people, by the people. Want to buy your Pack or Services from MandrakeSoft? Go to http://www.mandrakestore.com
Re: [expert] Copying a file across NFS
On Saturday 26 July 2003 10:41 pm, Rob Blomquist wrote: > On Saturday 26 July 2003 04:42 pm, Greg Meyer wrote: > > On Saturday 26 July 2003 01:58 pm, Rob Blomquist wrote: > > > I am seeing a lot of collisions at my hub and in ifconfig. Is it > > > possible that I have a NIC going bad? Or might there be another reason? > > > I have 8.0 Gb free on the drive recieving the file. > > > > Are you having trouble with all files or just the iso's. I think we need > > to determine if the problem has anything to do with the size of the file. > > It is just the isos, I have copied kernel-2.4.24.tar.gz to the same > directory and its about 30Mb and it moves sucessfully. > > Usually the problem crops up when 30-100Mb are copied over. I have had 30, > 80 and 100 Mb incomplete files on the server when it quits. > Are you seeing any errors in your logs? what does the exports file of the server, and the fstab file of the client look like? -- /g "Outside of a dog, a man's best friend is a book, inside a dog it's too dark to read" -Groucho Marx Want to buy your Pack or Services from MandrakeSoft? Go to http://www.mandrakestore.com
Re: [expert] Copying a file across NFS
On Saturday 26 July 2003 04:42 pm, Greg Meyer wrote: > On Saturday 26 July 2003 01:58 pm, Rob Blomquist wrote: > > I am seeing a lot of collisions at my hub and in ifconfig. Is it possible > > that I have a NIC going bad? Or might there be another reason? I have 8.0 > > Gb free on the drive recieving the file. > > Are you having trouble with all files or just the iso's. I think we need > to determine if the problem has anything to do with the size of the file. It is just the isos, I have copied kernel-2.4.24.tar.gz to the same directory and its about 30Mb and it moves sucessfully. Usually the problem crops up when 30-100Mb are copied over. I have had 30, 80 and 100 Mb incomplete files on the server when it quits. Rob -- Linux: For the people, by the people. Want to buy your Pack or Services from MandrakeSoft? Go to http://www.mandrakestore.com
Re: [expert] Copying a file across NFS
On Saturday 26 July 2003 01:58 pm, Rob Blomquist wrote: > I am seeing a lot of collisions at my hub and in ifconfig. Is it possible > that I have a NIC going bad? Or might there be another reason? I have 8.0 > Gb free on the drive recieving the file. Are you having trouble with all files or just the iso's. I think we need to determine if the problem has anything to do with the size of the file. -- /g "Outside of a dog, a man's best friend is a book, inside a dog it's too dark to read" -Groucho Marx Want to buy your Pack or Services from MandrakeSoft? Go to http://www.mandrakestore.com
