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27

Isn't this a situation where you should engineer around the circular dependencies? Set power-on delays in the server BIOS. You have multiple DNS servers, so that's a plus. DNS caching? Would this be as simple as using IP addresses or host files for your NFS or storage network? You didn't mention the particular virtualization technology, but it's possible to ...


24

First the lecture: Rule Number Zero: If you do not understand what something does, DO NOT TOUCH IT Deleting files "to save space" with no concept of what you are doing will anger the operating system gods, resulting problems similar to what you are now experiencing (Things break. Fixing them is often non-trivial). Now the sympathetic assistance: ...


21

You're looking at a lost cause. Save the data you need, and reinstall the operating system.


20

I tend to create a 1GB /boot. I leave a livecd image which has various repair tools in my /boot. I mostly do this for systems that at the remote sites I support. With the right configuration, and enough memory, grub2 can boot the image without extracting the contents. A couple times I have talked remote staff into rebooting the system to the livecd image ...


19

What is the recommended size for a linux /boot partition? The /boot parition contains the GRUB configuration, the kernel with their System.map, ... I think ~ 100MB is enough. And is it safe to not have a /boot partition? Yes. But a separate /boot partition has some advantages: as a rescue partition rootfs is on a LVM, RAID, is encrypted, or ...


18

Out of the box, you are guaranteed that iptables will start before the interface is brought up by the order of the startup scripts. Look at the "chkconfig" line in each startup script and you will see the runlevels it is "on" when active, the start order, and the stop order. You are not guaranteed that the interface will not be brought up if the iptables ...


15

You say in your comments that you're evaluating a netboot / network root environment. The first thing you must realize is there is no such thing as "vanilla" - you're not going to run CentOS 5.10 right out of the box with zero changes (if you think you are you're deluding yourself: NFS Root is already at least Strawberry, verging on Pistachio). If you want ...


14

These days, 100 Megabytes or 200 Megabytes is the norm. You do not need to have a /boot partition. However, it's good to have for flexibility reasons (LVM, encryption, BIOS limitations). Edit: The recommended size has been increased to 300MB-500MB. Also see: http://superuser.com/questions/66015/installing-ubuntu-do-i-really-need-a-boot-parition


12

Have a look at the update-rc.d man page. The third paragraph of the section named Installing Init Script Links reads … A common system administration error is to delete the links with the thought that this will "disable" the service, i.e., that this will prevent the service from being started. However, if all links have been deleted then the next ...


11

Why not just connect a USB CD\DVD drive and install from there?


11

All IBM uEFI Machines take ages to boot, as after the eon-taking uEFI initialization and module startup the legacy BIOS emulation kicks in and the PCI-E option ROMs get executed etc. etc. This is "normal" on all IBM uEFI machines - no matter if blade or standard rack server. You could disable legacy BIOS boot, the option ROMs, optimize the boot order and ...


10

Create a disk image. The following command will create a 10G sparse image: # dd if=/dev/zero of=mydisk.img bs=1 count=0 seek=10G 0+0 records in 0+0 records out 0 bytes (0 B) copied, 1.6554e-05 s, 0.0 kB/s # ls -lh mydisk.img -rw-r--r--. 1 root root 10G Jun 17 15:27 mydisk.img Partition the image with fdisk: # fdisk mydisk.img Make sure you create ...


10

Depending on your UPS status, this could be one of the few use-cases where an ACPI hibernate may be a good idea. Generally restore-from-hibernate beats out a boot-from-scratch, especially in the case of low-RAM SSD-based systems. If you have the ability, the 'shutdown' step for your UPS software can be set to hibernate the DNS server.


10

I'd suggest just using the user-data option to ec2-run-instances. It lets you give a script of some sort to the VM which will be run on first boot. If you're using ubuntu or debian, you can use cloud-init, which puts some nice polish on the process. If using cloud-init, you can use the [runcmd] section of the config file to specify arbitrary commands to run ...


10

If you're already rebooting, just boot into the Live CD, chroot into the server's root filesystem, and run passwd. Problem solved.


9

NFS is notoriously touchy when it comes to mounts being unavailable at mount time or mounts disappearing randomly. Particularly with older Linux releases, there were some very real and serious issues with both cases. Recent releases have gotten a lot better, but aren't yet perfect. For this, however, I would strongly recommend looking into AutoFS and the ...


9

You can use a Group Policy (or the local policy) to assign a startup script; you can configure it in the section Computer Configuration -> Windows Settings -> Scripts (Startup/Shutdown). You can also use Scheduled Tasks to configure a task to run at computer startup.


9

The first thing I'd try is running a LiveCD environment and just attempt to ungzip everything, hoping that would return the system to a bootable state. Note: I'd be concerned about potential data corruption if the original gzip process was interrupted. Otherwise I'd try to migrate the DB to a new system as others have suggested but as you've encountered ...


9

You can boot using a Grub fallback entry. Add another stanza with either your new (or old) options, then choose the known-good as the fallback. Look into adding the panic=5 option as well (resets a system following kernel crash)


9

You can indeed use Grub to boot once only. You can also specify a fallback boot. Essentially, you use default saved at the start of your grub.conf, to indicate that you want to boot a saved entry by default. Then at the end of your experimental boot, use savedefault # to set the older boot options as the new saved value. So that every time you boot the ...


8

Currently, Upstart in Ubuntu does not generate network events. Instead it calls traditional sysvinit. By default NetworkManager is installed and running; rather than emit network events to upstart, it contains a run-parts dispatcher (/etc/NetworkManager/dispatcher.d/) which itself simply relies on ifupdown's run-parts dispatcher (/etc/network/*.d/). In ...


8

The computer was booting off one of those disks you removed, and starting the OS from the Operating System disk (which is apparently a separate disk). This is what happens when someone carelessly installs an OS. You need to get the BCD on the OS disk and corrected for it's new location. You may be able to boot the Installation Disk and Repair the ...


8

There's no option here. Since the advent of the Nehalem and newer CPU's, the POST time on HP systems has grown tremendously. I see that you're using this as a workstation. Is there any option to leave the system running and take advantage of some of the BIOS power management options?


8

Install one system, boot it and check out the block layer statistics from /sys/block/${DEV}/stat e.g. /sys/block/sda/stat. Quoting from the documentation: The stat file consists of a single line of text containing 11 decimal values separated by whitespace. The fields are summarized in the following table, and described in more detail below: Name ...


7

If you look at the "chkconfig" line of /etc/init.d/network you'll see that the network has a start priority of "10". /etc/init.d/yourscript: #!/bin/bash # # yourscript short description # # chkconfig: 2345 9 20 # description: long description case "$1" in start) Do your thing !!! chkconfig yourscript off ;; ...


7

After 2 hours trying to boot, I don't think you have a choice. If it hasn't booted by now, it's not going to. Time to power it off, hard, if needed. And FWIW, those timeouts can be caused by bad or incompatible RAM. Pull out the new RAM before booting the system up again, or boot into a diagnostics/MEMtest CD and see what's up with those new DIMMs.


7

If your Linux boot partition is suddenly low on disk space, it probably means you have been accumulating old kernel images. To clear up space, you need only uninstall the old kernels. First, find out what kernels you have installed: rpm -qa | grep kernel | sort Next, find out what version you are running: tail /proc/version Lastly, uninstall the ...


7

This will depend on whether the filesystems are repaired enough for you to be able to mount those partitions from a LiveCD. Don't bother trying to boot the system yet. First, mount the partitions and unzip all the .gz files. This will give you working copies of init and system binaries. Then you can use grub to repair the boot sector. Then boot to single ...


7

I agree that your solution seems a bit complex, so I'll go with "give me some idea how this could be implemented in an entirely different way" :-) The standard solution for this is to use a configuration management system, such as puppet, and allow users to add their stuff to the puppet config for the server. Puppet will then push out the start script and ...


6

Microsoft's Process Monitor tool allows you to "capture" the boot process in a log file that can be later analyzed to reveal the exact points where your boot process isn't as fast as you want it to be. Then you can remove/play with the problematic processes or pinpoint-search the web for a specific solution.



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