Review the following items if you have problems either capturing a system crash dump or resizing the dump device.
If a crash dump was not created automatically, you can use the savecore command to save the crash dump.
A dump device is created automatically when you initially install a ZFS root file system or migrate to a ZFS root file system. In most cases, you will only need to adjust the size of the dump device if the default dump device size is too small. For example, on a large-memory system, the dump device size is increased to 40 Gbytes as follows:
# zfs set volsize=40G rpool/dump |
Resizing a large dump device can be a time-consuming process.
If, for any reason, you need to enable a dump device after you create a dump device manually, use syntax similar to the following:
# dumpadm -d /dev/zvol/dsk/rpool/dump Dump content: kernel pages Dump device: /dev/zvol/dsk/rpool/dump (dedicated) Savecore directory: /var/crash/t2000 Savecore enabled: yes Save compressed: on |
A system with 128 Gbytes or greater memory will need a larger dump device than the dump device that is created by default. If the dump device is too small to capture an existing crash dump, a message similar to the following is displayed:
# dumpadm -d /dev/zvol/dsk/rpool/dump dumpadm: dump device /dev/zvol/dsk/rpool/dump is too small to hold a system dump dump size 36255432704 bytes, device size 34359738368 bytes |
For information on sizing the swap and dump devices, see Planning for Swap Space in System Administration Guide: Devices and File Systems.
You cannot currently add a dump device to a pool with multiple top level-devices. You will see a message similar to the following:
# dumpadm -d /dev/zvol/dsk/datapool/dump dump is not supported on device '/dev/zvol/dsk/datapool/dump': 'datapool' has multiple top level vdevs |
Add the dump device to the root pool, which cannot have multiple top-level devices.