Installing patches using a jail

1. A system, comprising:

a processor; and

a memory that stores executable instructions that, when executed by the processor, facilitate performance of operations, comprising:

booting a first computing node from a first partition;

after the booting, installing a new operating system on a second partition that has been mounted to the first computing node at a first location within a file system of the first computing node to replace an existing operating system on the second partition;

setting an apparent root directory for patch installation to a mount point of the second partition, wherein the apparent root directory is a second location within the file system that differs from the first location, and wherein the second partition remains mounted to the first computing node while the apparent root directory is presented to a patch that is subject to patch installation;

after the setting, performing the patch installation inside the apparent root directory; and

rebooting the first computing node from the second partition.

2. The system of claim 1 , wherein the new operating system is a first new operating system, wherein the apparent root directory for the patch installation is a first apparent root directory for first patch installation, and wherein the operations further comprise:

installing a second new operating system on the first partition;

setting a second apparent root directory for patch installation to a mount point of the first partition;

performing a second patch installation inside the second apparent root directory; and

rebooting the first computing node from the first partition.

3. The system of claim 1 , wherein the setting the apparent root directory for patch installation to the mount point of the second partition comprises:

creating a jail with the mount point of the second partition as the apparent root directory in the jail.

4. The system of claim 1 , wherein the setting the apparent root directory for patch installation to the mount point of the second partition comprises:

copying or linking at least one system file to the apparent root directory.

5. The system of claim 1 , wherein the setting the apparent root directory for patch installation to the mount point of the second partition comprises:

changing a root directory for an environment used for patch installation.

6. The system of claim 1 , wherein the performing the patch installation inside the apparent root directory comprises:

executing a first patch script in association with installing a first patch, the first patch script referencing the apparent root directory.

7. The system of claim 6 , wherein the first patch script referencing the apparent root directory comprises the first patch script making an absolute reference to a file system location of the second partition.

8. A method, comprising:

installing, by a system comprising a processor, a new operating system on a second partition that has been mounted to a first location within a file system of a first partition of a first computing node that is booted from the first partition, to replace an existing operating system on the second partition;

creating, by the system, a jail for patch installation to the second partition, wherein the jail comprises a second location within the file system of the first partition that differs from the first location, and wherein the second partition remains mounted to the first computing node while the second location is presented as a root directory to a patch for which patch installation is performed;

performing, by the system, the patch installation inside the jail; and

rebooting, by the system, the first computing node from the second partition.

9. The method of claim 8 , wherein the performing the patch installation inside the jail comprises:

installing, by the system, at least a first patch for the new operating system in the second partition.

10. The method of claim 8 , wherein the performing the patch installation inside the jail comprises:

evaluating, by the system, one or more previously-installed patches for the second partition;

determining, by the system, a missing patch based on the one or more previously-installed patches for the second partition and a registered patch for the first computing node; and

determining, by the system, at least one operation to perform to apply the missing patch to the second partition.

11. The method of claim 8 , wherein the rebooting the first computing node from the second partition comprises:

booting, by the system, the first computing node from the new operating system on the second partition as patched by one or more patches from the performing the patch installation.

12. The method of claim 8 , wherein the installing the new operating system on the second partition comprises:

unpacking, by the system, an upgrade image that comprises the new operating system in the second partition.

13. The method of claim 8 , wherein the rebooting the first computing node from the second partition comprises:

setting, by the system, a configuration of the first computing node to indicate that the first computing node will boot from the second partition when the first computing node reboots.

14. The method of claim 8 , wherein the new operating system is a first new operating system, and further comprising:

installing, by the system, a second new operating system on the first partition;

creating, by the system, a second jail for patch installation to the first partition;

performing, by the system, a second patch installation inside the second jail; and

rebooting, by the system, the first computing node from the first partition.

15. A non-transitory computer-readable medium comprising instructions that, in response to execution, cause a system comprising a processor to perform operations, comprising:

installing a new operating system on a second partition that is mounted to a first location within a file system of a first partition of a first computing node that is booted from the first partition;

creating a jail for patch installation to the second partition, wherein the jail comprises a second location within the file system of the first partition that differs from the first location, and wherein the second partition remains mounted to the first computing node while the second location is presented as a root directory to a patch for which patch installation is performed;

performing the patch installation inside the jail; and

rebooting the first computing node from the second partition.

16. The non-transitory computer-readable medium of claim 15 , wherein the first partition comprises a boot partition.

17. The non-transitory computer-readable medium of claim 15 , wherein the second partition comprises a backup firmware image partition.

18. The non-transitory computer-readable medium of claim 17 , wherein the backup firmware image partition comprises a file system partition that contains a known valid operating system configuration for the first computing node.

19. The non-transitory computer-readable medium of claim 17 , wherein the backup firmware image partition comprises a file system partition that is booted from in response to the first computing node failing to boot from the first partition.

20. The non-transitory computer-readable medium of claim 15 , wherein the new operating system is a first new operating system, and wherein the operations further comprise:

installing a second new operating system on the first partition;

performing a second patch installation inside a second jail of the first partition; and

rebooting the first computing node from the first partition.