On Thu, Apr 19, 2012 at 10:59:17AM +0200, Harald Hoyer wrote: > Am 19.04.2012 00:28, schrieb Vivek Goyal: > > Hi, > > > > I am trying to dump kernel vmcore to an software iscsi target (kdump). > > kdump specifies the dump destination using "--mount" option. But dracut > > does not even include the "iscsi" module and associated device is not > > mounted in second kernel. > > > > Following is the dracut command line as called by /sbin/mkdumprd. > > > > dracut -m kdumpbase --add dash --add fstab-sys --add kernel-modules -c /dev/null -I /sbin/makedumpfile --mount '/dev/mapper/vg-lv_root / ext4 rw,seclabel,relatime,user_xattr,barrier=1,data=ordered' --mount '/dev/mapper/mpatha /mnt/common ext4 rw,seclabel,relatime,user_xattr,barrier=1,stripe=16,data=ordered' -M -f /boot/initramfs-3.3.2-1.fc17.x86_64kdump.img 3.3.2-1.fc17.x86_64 > > "-m kdumpbase" - This tells dracut to only use the kdumpbase dracut module > So, because the iscsi dracut module is not added, dracut does not even check() it. > > Why is it "-m kdumpbase" and not "--add kdumpbase" ??? I don't know why -m is being used instead of --add. I tried changing it to --add and uncompressed initramfs size changed from 36MB to 72MB. To me 32MB size itself is big. IIRc, in RHEL6 using our own mkinitrd, we had uncomressed initrd size close to 25MB. In kdump environment we work in very restricted memory conditions. Currently we reserve 128MB and there are calls to reduce it further. This 128MB should load kernel, initramfs and run all the tools in initramfs to actually save the vmcore to the target. So we need to figure out how can we reduce the size of initramfs for kdump case. In the next mail I will add the output of --debug both for -m kdumpbase and --add kdumpbase. >From kdump perspective, we only need to mount targets as specified by --mount option. We might not want to mount even root and it depends on kdump.conf. If root is needed, we will pass that too on command line using --mount. So this is little different from -H option. Can we modify dracut in such a way so that it packs only those modules need to mount targets as specified --mount options? Thanks Vivek -- To unsubscribe from this list: send the line "unsubscribe initramfs" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
