/crossbeam/bin/xos-copy-dist and RAID-1 considerations
Article ID: 168034
Updated On:
Products
XOS
Issue/Introduction
When XOS is configured as RAID-1 (CPM8600+), the copy disk distribution process will only work when both disks are present.Performing copy disk distribution on a CPM with RAID configured and one disk present results in the following error message:
ERROR: Failed to create swap space for /dev/md10 For detail steps and outputs, see attached file broken raid.log
ERROR: Failed to create swap space for /dev/md10 For detail steps and outputs, see attached file broken raid.log
Cause
Copy disk distribution is a well-known functionality and useful for safe upgrade situations. However, if XOS is configured as RAID-1 (CPM8600+), the copy process will only work when both disks are present. This seems to be obvious, but because more than one partition can be created even when only one disk is inserted, you may try to copy from one partition to another on the same disk. This will not work.
The restriction is created by the swap partition and the way we configure it on RAID-1.
NOTE: You need enter single user mode from the grub menu, or by changing the kernel boot line inside /boot/grub/grub.conf and then rebooting the CPM. If you run "init 1" directly from CPM, the command /crossbeam/bin/xos-copy-dist will fail.
Performing copy disk distribution on a CPM with RAID configured and one disk present:
1 - View available distributions
sh-2.05a# /crossbeam/bin/xos-toggle-boot -l
modprobe:
modprobe: Can't locate module vfat
modprobe:
modprobe: Can't locate module freevfat
System is running on Distribution 1 (Release 8.1.0)
Default kernel for next boot is Distribution 1 1:
Linux (2.4.21-47.ELuni) (Distribution 1 - 8.1.0)
Available kernels: 0:
Linux (2.4.21-47.EL) (Distribution 1 - 8.1.0) 1:
Linux (2.4.21-47.ELuni) (Distribution 1 - 8.1.0) 2:
Linux (2.4.21-47.ELuni) (Distribution 1 - 8.1.0)
Preparing file systems for the destination distribution
ERROR: Failed to create swap space for /dev/md10
For detail steps and outputs, see attached file "broken raid.log".
The failure happens because the Linux kernel can use the swap partition on disk A and disk B (not at the same time). If a software issue/crash happened on swap partition of disk A, the kernel will failover to the swap partition on disk B. This is not possible with "normal" partitions and RAID-1, as they only failover in the case of a physical problem.
The restriction is created by the swap partition and the way we configure it on RAID-1.
NOTE: You need enter single user mode from the grub menu, or by changing the kernel boot line inside /boot/grub/grub.conf and then rebooting the CPM. If you run "init 1" directly from CPM, the command /crossbeam/bin/xos-copy-dist will fail.
Performing copy disk distribution on a CPM with RAID configured and one disk present:
1 - View available distributions
sh-2.05a# /crossbeam/bin/xos-toggle-boot -l
modprobe:
modprobe: Can't locate module vfat
modprobe:
modprobe: Can't locate module freevfat
System is running on Distribution 1 (Release 8.1.0)
Default kernel for next boot is Distribution 1 1:
Linux (2.4.21-47.ELuni) (Distribution 1 - 8.1.0)
Available kernels: 0:
Linux (2.4.21-47.EL) (Distribution 1 - 8.1.0) 1:
Linux (2.4.21-47.ELuni) (Distribution 1 - 8.1.0) 2:
Linux (2.4.21-47.ELuni) (Distribution 1 - 8.1.0)
2 - Copy distribution
Preparing file systems for the destination distribution
ERROR: Failed to create swap space for /dev/md10
For detail steps and outputs, see attached file "broken raid.log".
The failure happens because the Linux kernel can use the swap partition on disk A and disk B (not at the same time). If a software issue/crash happened on swap partition of disk A, the kernel will failover to the swap partition on disk B. This is not possible with "normal" partitions and RAID-1, as they only failover in the case of a physical problem.
Resolution
To copy a distribution in a RAID-1 environment, both disks should be available and synchronized. If it is necessary to change the second disk due to an RMA, use /crossbeam/bin/xos-raid-add to sync both disks.
Performing copy disk distribution on a CPM with RAID configured and 2 disks present and RAID synchronized:
1 - View available distributions
sh-2.05a# /crossbeam/bin/xos-toggle-boot -l
System is running on Distribution 1 (Release 8.1.4)
Default kernel for next boot is Distribution 1 1:
Linux (2.4.21-47.ELuni) (Distribution 1 - 8.1.4) Available kernels: 0:
Linux (2.4.21-47.EL) (Distribution 1 - 8.1.4)
1: Linux (2.4.21-47.ELuni) (Distribution 1 - 8.1.4)
2: Linux (2.4.21-47.ELuni) (Distribution 1 - 8.1.4)
3: Linux (2.4.21-47.EL) (Distribution 2 - 8.1.1)
4: Linux (2.4.21-47.ELuni) (Distribution 2 - 8.1.1)
5: Linux (2.4.21-47.ELuni) (Distribution 2 - 8.1.1)
2 - Copy distribution
sh-2.05a# /crossbeam/bin/xos-copy-dist -d 2
Copying distribution. Please be patient... ...
Done
The CPM boots from second distribution. For detail steps and outputs, see attached file raid.log
Performing copy disk distribution on a CPM with RAID configured and 2 disks present and RAID synchronized:
1 - View available distributions
sh-2.05a# /crossbeam/bin/xos-toggle-boot -l
System is running on Distribution 1 (Release 8.1.4)
Default kernel for next boot is Distribution 1 1:
Linux (2.4.21-47.ELuni) (Distribution 1 - 8.1.4) Available kernels: 0:
Linux (2.4.21-47.EL) (Distribution 1 - 8.1.4)
1: Linux (2.4.21-47.ELuni) (Distribution 1 - 8.1.4)
2: Linux (2.4.21-47.ELuni) (Distribution 1 - 8.1.4)
3: Linux (2.4.21-47.EL) (Distribution 2 - 8.1.1)
4: Linux (2.4.21-47.ELuni) (Distribution 2 - 8.1.1)
5: Linux (2.4.21-47.ELuni) (Distribution 2 - 8.1.1)
2 - Copy distribution
sh-2.05a# /crossbeam/bin/xos-copy-dist -d 2
Copying distribution. Please be patient... ...
Done
The CPM boots from second distribution. For detail steps and outputs, see attached file raid.log
Workaround
N/A
Feedback
Yes
No
Powered by
