Re: Still Considering Debian - But Stuck!
Fred Whipple wrote: Hi Everyone, A while back I asked for some feedback and got a very rich set of info from folks about Debian used in a stable ISP environment as compared to other OS's and distributions. All the info was very helpful and helped us further solidify our desire (though not yet decision) to make Debian our platform as we move forward. We've run into a couple rather HUGE issues, though, that I'd like to get further feedback on. Not that I couldn't figure it all out for myself, but nothing beats someone else's experience when it comes to saving me the time and heartache ;-) Just about everyone warned me that the stable Debian distribution would be old and well tested/maintained, but I'm not sure I was prepared for just HOW old... Our company uses Java --- a LOT of Java. We therefore use a lot of threads, and a lot of threads. And a whole mess of threads, too. Under Red Hat 7.3, we found that when the system had a total of say, 10,000 PID's given out (nearly all of them to threads) the system would become very unstable. When we moved to Red Hat 9 for the affected systems, which includes the new 0(1) scheduler, and either a different kind of thread support in either the kernel or GlibC, this problem went away. I'm honestly not sure who is responsible for the way threads are handled, and I suspect it's not exclusively the kernel, but under RH9 each JVM (or any app with threads) gets a single PID as normal and all very strange behavior that we saw under RH7.3 disappears. I see that Debian 3.0r2 includes a nicely aged (like fine cheese) Linux 2.2 kernel. While I'm certain the aging process only makes its flavour stronger and more delectable, I'm afraid it's going to choke at the thought of 10,000 threads. Say nothing of 20,000. Now I imagine it's not so difficult to simply compile a recent 2.4 (2.5?) kernel and go from there. Is this fair? Or would you suppose that the current stable Debian is too old in other areas to properly handle kernel 2.4? Even if I replace the kernel, I'm concerned that there's more involved with the more efficient handling of threads from RH 7.3 to RH 9 than just a kernel change -- I have to think there was a significant rework of some libraries that made threads more efficient under RH9 as well. Would anyone be able to identify exactly what that re-working was, and conjecture if they think it can be done under 3.0r2? For that matter, would I at that point be running so much new technology that I may as well be running an unstable distribution of Debian? Finally, while I'm messing around with the kernel, I'd have to include support for ext3fs. In our environment, journaling is not an option, it's a base requirement. Of course replacing the kernel would pretty much give me kernel-level support for it. From that point, how complicated is it to get the rest of the tools to play nicely with ext3fs? I'd imagine that a large set of tools would need to be replaced, including e2fsck, mount, umount, etc. Thanks once again for all the info so far! -Fred Whipple The kernel can be made to support as many processes as you would like. Install a custom kernel http://sohd.suffolk.lib.ny.us/docs/debkern/debkern.htm. For ext3 support simply from a root prompt type tune2fs -j /dev/sda1 for the first scsi partition on the first scsi disk. I have never tried to support 1 processes on one box however: I use a linux virtual server cluster. http://www.linuxvirtualserver.org/ hope this helps bye for now syl
Re: Still Considering Debian - But Stuck!
Fred Whipple wrote: Hi Everyone, A while back I asked for some feedback and got a very rich set of info from folks about Debian used in a stable ISP environment as compared to other OS's and distributions. All the info was very helpful and helped us further solidify our desire (though not yet decision) to make Debian our platform as we move forward. We've run into a couple rather HUGE issues, though, that I'd like to get further feedback on. Not that I couldn't figure it all out for myself, but nothing beats someone else's experience when it comes to saving me the time and heartache ;-) Just about everyone warned me that the stable Debian distribution would be old and well tested/maintained, but I'm not sure I was prepared for just HOW old... Our company uses Java --- a LOT of Java. We therefore use a lot of threads, and a lot of threads. And a whole mess of threads, too. Under Red Hat 7.3, we found that when the system had a total of say, 10,000 PID's given out (nearly all of them to threads) the system would become very unstable. When we moved to Red Hat 9 for the affected systems, which includes the new 0(1) scheduler, and either a different kind of thread support in either the kernel or GlibC, this problem went away. I'm honestly not sure who is responsible for the way threads are handled, and I suspect it's not exclusively the kernel, but under RH9 each JVM (or any app with threads) gets a single PID as normal and all very strange behavior that we saw under RH7.3 disappears. I see that Debian 3.0r2 includes a nicely aged (like fine cheese) Linux 2.2 kernel. While I'm certain the aging process only makes its flavour stronger and more delectable, I'm afraid it's going to choke at the thought of 10,000 threads. Say nothing of 20,000. Now I imagine it's not so difficult to simply compile a recent 2.4 (2.5?) kernel and go from there. Is this fair? Or would you suppose that the current stable Debian is too old in other areas to properly handle kernel 2.4? Even if I replace the kernel, I'm concerned that there's more involved with the more efficient handling of threads from RH 7.3 to RH 9 than just a kernel change -- I have to think there was a significant rework of some libraries that made threads more efficient under RH9 as well. Would anyone be able to identify exactly what that re-working was, and conjecture if they think it can be done under 3.0r2? For that matter, would I at that point be running so much new technology that I may as well be running an unstable distribution of Debian? Finally, while I'm messing around with the kernel, I'd have to include support for ext3fs. In our environment, journaling is not an option, it's a base requirement. Of course replacing the kernel would pretty much give me kernel-level support for it. From that point, how complicated is it to get the rest of the tools to play nicely with ext3fs? I'd imagine that a large set of tools would need to be replaced, including e2fsck, mount, umount, etc. Thanks once again for all the info so far! -Fred Whipple The kernel can be made to support as many processes as you would like. Install a custom kernel http://sohd.suffolk.lib.ny.us/docs/debkern/debkern.htm. For ext3 support simply from a root prompt type tune2fs -j /dev/sda1 for the first scsi partition on the first scsi disk. I have never tried to support 1 processes on one box however: I use a linux virtual server cluster. http://www.linuxvirtualserver.org/ hope this helps bye for now syl -- To UNSUBSCRIBE, email to [EMAIL PROTECTED] with a subject of "unsubscribe". Trouble? Contact [EMAIL PROTECTED]
Re: FreeBSD/ Redhat / Debian
Vahric MUHTARYAN wrote: Hi Everybody , I will be new user of Debian. For quick tour I want to learn and I want to get your advise about Comparing other OS with Debian . Do you have any link about some test with Debian and athor OS, Please share you exprience with me .. Thanks Vahric MUHTARYAN Dear Sir, My experience has been with redhat and debian. Freebsd I have not much experience with and therefore cannot comment. Debian and redhat have different philosophies. Redhat being a commercial company is under pressure to release new versions of its os on a regular basis. Debian is a volunteer, non-commercial organization that releases software when "it is ready". For the latest and greatest software choose redhat (now fedora) but for stable well tested software choose debian. The install of debian is somewhat more difficult for inexperienced users but the admin of debian machines is much simpler. Evaluate your needs honestly then repost and then we could be of more help bye for now and good luck syl
Re: FreeBSD/ Redhat / Debian
Vahric MUHTARYAN wrote: Hi Everybody , I will be new user of Debian. For quick tour I want to learn and I want to get your advise about Comparing other OS with Debian . Do you have any link about some test with Debian and athor OS, Please share you exprience with me .. Thanks Vahric MUHTARYAN Dear Sir, My experience has been with redhat and debian. Freebsd I have not much experience with and therefore cannot comment. Debian and redhat have different philosophies. Redhat being a commercial company is under pressure to release new versions of its os on a regular basis. Debian is a volunteer, non-commercial organization that releases software when "it is ready". For the latest and greatest software choose redhat (now fedora) but for stable well tested software choose debian. The install of debian is somewhat more difficult for inexperienced users but the admin of debian machines is much simpler. Evaluate your needs honestly then repost and then we could be of more help bye for now and good luck syl -- To UNSUBSCRIBE, email to [EMAIL PROTECTED] with a subject of "unsubscribe". Trouble? Contact [EMAIL PROTECTED]
