Online volume repair

1. A machine-readable storage medium comprising instructions executable by a processing resource to:

receive a request to access a compressed page of a volume, wherein the compressed page includes compressed data and compression metadata;

identify an error in the compression metadata or the compressed data;

based on the identification of an error in the compression metadata or the compressed data when the request is a read request or a partial overwrite request, flag the compressed page as inconsistent in a translation table entry associated with the compressed page, wherein the translation table entry is part of a translation table for the volume; and

based on the identified error and the request, handle repair of the error while the volume is online.

2. The machine-readable storage medium of claim 1 , wherein the instructions to identify the error comprise instructions executable by the processing resource to:

validate a checksum to determine whether the compression metadata has a compression metadata error; and

based on a determination that the compression metadata does not have a compression metadata error, decompress the compressed data of the compressed page to determine whether the compressed data has a data error.

3. The machine-readable storage medium of claim 2 , wherein the instructions to handle repair of the error while the volume is online comprise instructions executable by the processing resource to:

based on the error being a compression metadata error or a data error and the request being a read request:

alert a user to initiate an online repair;

determine whether the user has initiated the online repair;

based on the determination that the user has initiated the online repair, identify each compressed page within the translation table;

perform a partial data-less write to each identified compressed page to determine each compressed page that generates a compression metadata error or a data error; and

terminate each compressed page that generates a compression metadata error or a data error to repair the volume.

4. The machine-readable storage medium of claim 1 , wherein the instructions to handle repair of the error while the volume is online comprise instructions executable by the processing resource to:

when the request is a full page overwrite request and the error is a compression metadata error:

perform the full page overwrite at a given location other than where the compressed page is stored; and

update the translation table entry associated with the compressed page to point to the given location.

5. The machine-readable storage medium of claim 1 , wherein the instructions to handle repair of the error while the volume is online comprise instructions executable by the processing resource to:

based on the error being a compression metadata error or a data error, and the request being a partial overwrite request:

determine whether another request to access the compressed page has been received; and

based on the another request being another partial overwrite request or a read request, alert the user to initiate an online repair.

6. The machine-readable storage medium of claim 1 , wherein the volume is a logical volume.

7. The machine-readable storage medium of claim 5 , wherein the instructions to handle repair of the error while the volume is online comprise instructions executable by the processing resource to:

determine whether the user has initiated the online repair;

based on a determination that the user has initiated the online repair, identify each compressed page within the translation table;

perform a partial data-less write to each identified compressed page to determine each compressed page that generates a compression metadata error or a data error; and

terminate each compressed page that generates a compression metadata error or a data error to repair the volume.

8. The machine-readable storage medium of claim 5 , wherein the instructions to handle the error while the volume is online comprise instructions executable by the processing resource to:

based on the another request being a full page overwrite request:

perform the full page overwrite at a given location other than where the compressed page is stored without alerting the user, wherein the error is a compression metadata error; and

update the translation table entry associated with the compressed page to point to the another location.

9. The machine-readable storage medium of claim 1 , wherein the compressed page includes up to eight virtual pages of data and the compression metadata includes a reference count, a compressed page offset for each virtual page of data, a virtual page address for each virtual page of data, and a check value.

10. A device comprising:

a processing resource; and

a machine-readable storage medium encoded with instructions executable by the processing resource to:

receive a request to access a compressed page of a volume,

wherein the compressed page includes compressed data and compression metadata, and

wherein the request is a read request, a partial overwrite request, or a full page overwrite request;

identify an error in the compression metadata or the compressed data; and

based on identification of an error in the compression metadata when the request is a full page overwrite request, perform the full page overwrite at a given location other than where the compressed page is stored and update a translation table entry associated with the compressed page to point to the given location, wherein the translation table entry is part of a translation table for the volume; and

based on and the request being a partial overwrite request, flag the compressed page as inconsistent in the translation table entry, wherein the translation table entry is part of a translation table for the volume.

11. The device of claim 10 , wherein the instructions are executable by the processing resource to, based on the error being a compression metadata error or a data error and the request being a read request, alert a user to initiate an online repair.

12. The device of claim 11 , wherein the instructions are executable by the processing resource to:

determine whether the user has initiated the online repair;

based on the determination that the user has initiated the online repair, identify each compressed page within the translation table;

perform a partial data-less write to each identified compressed page to determine each compressed page that generates a compression metadata error or a data error; and

terminate each compressed page that generates a compression metadata error or a data error to repair the volume.

13. The device of claim 10 , wherein the volume is a logical volume.

14. The device of claim 10 , wherein the instructions are executable by the processing resource to:

when the request is a partial overwrite request:

determine whether another request to access the compressed page has been received;

based on the another request being a full page overwrite request;

perform the full page overwrite at a given location other than where the compressed page is stored without alerting the user, wherein the error is a compression metadata error, and update the translation table entry associated with the compressed page to point to the given location; and

based on the another request being another partial overwrite request or a read request, alert the user to initiate the online repair.

15. The device of claim 10 , wherein the instructions are executable by the processing resource to:

based on the error being a compression metadata error and the request being a full page overwrite request:

perform the full page overwrite at a given location other than where the compressed page is stored; and

update the translation table entry associated with the compressed page to point to the given location.

16. A method of a processing resource, the method comprising:

receiving a request to access a compressed page of a volume, wherein the compressed page includes compressed data and compression metadata;

determining whether the request is a read request, a partial overwrite request, or a full page overwrite request;

determining whether an error exists in the compressed page;

based on a determination that an error exists in the compressed page and based on the request, handling repair of the error while the volume is online,

wherein, when the request is a full page overwrite request and the error in the compressed page is a compression metadata error, the handling repair of the error comprises:

performing the full page overwrite at a given location other than where the compressed page is stored; and

updating a translation table entry associated with the compressed page to point to the given location, wherein the translation table entry is part of a translation table for the volume.

17. The method of claim 16 , wherein, when the request is a read request, the handling repair of the error while the volume is online comprises:

flagging the compressed page as inconsistent in the translation table entry associated with the compressed page;

alerting a user to initiate an online repair;

determining whether the user has initiated the online repair;

based on a determination that the user has initiated the online repair, identifying each compressed page within the translation table;

performing a partial data-less write to each identified compressed page to determine each compressed page that generates a compression metadata error or a data error;

terminating each compressed page that generates a compression metadata error or a data error to repair the volume; and

clearing any inconsistent flag for each compressed page that does not generate a compression metadata error or a data error.

18. The method of claim 16 , wherein, when the request is the partial overwrite request, the handling repair of the error while the volume is online comprises:

flagging the compressed page as inconsistent in the translation table entry associated with the compressed page;

determining whether another request to access the compressed page has been received;

based on a determination that the another request is a full page overwrite request:

performing the full page overwrite at a given location other than where the compressed page is stored, wherein the error is a compression metadata error, and

updating the translation table entry associated with the compressed page to point to the given location and clearing the inconsistent flag; and

based on a determination that the another request is a partial overwrite request or a read request has been received, alerting a user to initiate an online repair.

19. The method of claim 16 , wherein the volume is a logical volume.