Differences

This shows you the differences between two versions of the page.

--- haas:system:sokraits_halfadder.offbyone.lan [2014/10/04 13:49] – [/tmp as noexec] wedge
+++ haas:system:sokraits_halfadder.offbyone.lan [2014/10/04 14:41] (current) – [rsync to fileserver] wedge
@@ Line 1108: / Line 1108: @@
 Wait at least 5 minutes for data reporting to make it into graphable form.
+=====Sync'ing to data store=====
+Since we've been successful running the systems out of a RAMdisk, care must be taken to preserve any changes in the event of a reboot or power failure.
+====rsync to disk====
+In this light, I first had the systems rsync'ing to their local SSD (boot drive). I rigged up a custom cronjob than ran 3 times a day. It looks as follows:
+<code>
+*/8 *   *   *     (mkdir -p /tmp/sda1; mount /dev/sda1 /tmp/sda1; rsync -av --one-file-system / /tmp/sda1/; umount /tmp/sda1)
+</code>
+====rsync to fileserver====
+This worked handily until sokraits lost its boot drive (again! In 2 months time!) so I decided to investigate netbooting using an NFSroot.
+In the process, I may have finally made a breakthrough in my longtime desire to put the entire system IN the initial ramdisk (so it would be running in RAM from the get-go). Turns out, according to the manual page, you merely have to put the system IN the initrd file... obviously one needs adequate memory (2x at boot- enough for the initrd, and enough to decompress it).
+My cron job changed as follows:
+<code>
+*/8 *   *   *     (rsync -av --one-file-system / data.lair.lan:/export/tftpboot/netboot/halfadder/disk/)
+</code>
+I plan to rig up either some daily autogeneration of the initrd, or have a script on standby that can use to make it. This will then become the method of booting both sokraits and halfadder (and potentially freeing up a still-working SSD in the process! Which I can use in data2).
+On the fileserver, I then obtain the latest copy of the hypervisor, kernel, and generate a new all-system initrd:
+<cli>
+data1:/export/tftpboot/netboot/halfadder# cp disk/boot/xen-4.4-amd64.gz .
+data1:/export/tftpboot/netboot/halfadder# cp disk/boot/vmlinuz-3.16-2-amd64 linux
+data1:/export/tftpboot/netboot/halfadder# cd disk
+data1:/export/tftpboot/netboot/halfadder/disk# find . | cpio -c -o | gzip -9 > ../initrd.gz
+data1:/export/tftpboot/netboot/halfadder/disk#
+</cli>
+====pxeboot file for sokraits/halfadder====
+On the fileserver, in **/export/tftpboot/pxelinux.cfg/** are two files, **0A50012E** (sokraits) and **0A50012F** (halfadder)... they are named according to the machine's IP address (only in hex).
+The file(s) contain:
+<code>
+default netboot
+prompt 1
+timeout 2
+label netboot
+    kernel mboot.c32
+    append netboot/halfadder/xen-4.4-amd64.gz --- netboot/halfadder/linux console=tty0 root=/dev/ram0 ro --- netboot/halfadder/initrd.gz
+label memtest
+    kernel distros/memtest/memtest86+
+</code>
 =====References=====

Lab46 Wiki

User Tools

Site Tools

Differences

Page Tools