Hybrid NVRAM logging in filesystem namespace

• US 10,613,941 B1
• Filed: 09/30/2015
• Issued: 04/07/2020
• Est. Priority Date: 09/30/2015
• Status: Active Grant

• Current Assignee: Emc IP Holding Company LLC (Dell Technologies Inc.)
• Original Assignee: Emc IP Holding Company LLC (Dell Technologies Inc.)
• Inventors: Shang, Pengju, Mathew, George, Bhagwat, Dhawal, Singh, Pranay, Koay, Englin
• Primary Examiner(s): Padmanabhan, Mano
• Assistant Examiner(s): Edouard, Jean C
• Application Number:
  US14/871,051
• Time in Patent Office: 1,651 Days
• Field of Search: 711104
• CPC Class Codes: G06F 11/1453 using de-duplication of the data
• CPC Class Codes: G06F 11/1456 Hardware arrangements for backup
• CPC Class Codes: G06F 11/1464 for networked environments
• CPC Class Codes: G06F 11/1469 Backup restoration techniques
• CPC Class Codes: G06F 11/1471 involving logging of persistent data for recovery
• CPC Class Codes: G06F 16/1805 Append-only file systems, e.g. using logs or journals to store data
• CPC Class Codes: G06F 16/1815 Journaling file systems
• CPC Class Codes: G06F 2201/84 Using snapshots, i.e. a logical point-in-time copy of the data
• CPC Class Codes: G06F 3/0608 Saving storage space on storage systems
• CPC Class Codes: G06F 3/0619 in relation to data integrity, e.g. data losses, bit errors
• CPC Class Codes: G06F 3/0641 De-duplication techniques
• CPC Class Codes: G06F 3/065 Replication mechanisms
• CPC Class Codes: G06F 3/067 Distributed or networked storage systems, e.g. storage area networks [SAN], network attached storage [NAS]
• CPC Class Codes: G06F 3/0679 Non-volatile semiconductor memory device, e.g. flash memory, one time programmable memory [OTP]

Abstract

In one example, a method for writing data includes receiving a write request and performing a first type of logging process in connection with the write request, and creating a corresponding first logging record. Additionally, a second type of logging process is performed in connection with the write request, and a corresponding second logging record created, where the second type of logging process is different from the first type of logging process. Next, a determination is made, as between the two logging records, which of the logging records requires the least amount of non-volatile random access memory (NVRAM), and the logging record that requires the least amount of NVRAM is written to the NVRAM.

Claims

1. A non-transitory storage medium having stored therein instructions that are executable by one or more hardware processors to perform operations comprising:

determining an amount of non-volatile random access memory (NVRAM) needed for a set of one or more write requests, and allocating the amount of NVRAM to the set of one or more write requests;

receiving a write request;

performing a first type of logging process in connection with the write request, and creating a corresponding first logging record;

performing a second type of logging process in connection with the write request, and creating a corresponding second logging record, wherein the second type of logging process is different from the first type of logging process;

determining, as between the two logging records, which of the logging records requires the least amount of non-volatile random access memory (NVRAM); and

writing, to NVRAM, the logging record that requires the least amount of NVRAM.

2. The non-transitory storage medium as recited in claim 1, wherein one of the logging processes is a physical logging process.

3. The non-transitory storage medium as recited in claim 1, wherein one of the logging processes is a logical logging process.

4. The non-transitory storage medium as recited in claim 1, wherein the first logging process is a physical logging process, and the second logging process is a logical logging process.

5. The non-transitory storage medium as recited in claim 1, wherein the first logging record comprises a (key, value) pair.

6. The non-transitory storage medium as recited in claim 1, wherein the second logging record comprises a (operation type, metadata) pair.

7. The non-transitory storage medium as recited in claim 1, wherein the logging record written to NVRAM is either a physical logging record or a logical logging record.

8. The non-transitory storage medium as recited in claim 1, further comprising determining a first threshold NVRAM space requirement that corresponds to the first type of logging process, and determining a second threshold NVRAM space requirement that corresponds to the second type of logging process.

9. The non-transitory storage medium as recited in claim 8, wherein the first threshold NVRAM space requirement and the second threshold NVRAM space requirement each respectively comprise a threshold at which one of the first logging process and the second logging process is preferred over the other of the first logging process and the second logging process.

10. The non-transitory storage medium as recited in claim 1, wherein the NVRAM is allocated on a namespace basis.

11. A non-transitory storage medium having stored therein instructions that are executable by one or more hardware processors to perform operations comprising:

determining an amount of non-volatile random access memory (NVRAM) needed for a set of one or more write requests, and allocating the amount of NVRAM to the set of one or more write requests;

writing data by performing the following;

receiving a write request;

performing a first type of logging process in connection with the write request, and creating a corresponding first logging record;

performing a second type of logging process in connection with the write request, and creating a corresponding second logging record, wherein the second type of logging process is different from the first type of logging process;

determining, as between the two logging records, which of the logging records requires the least amount of non-volatile random access memory (NVRAM); and

creating a stored logging record by writing, to NVRAM, the logging record that requires the least amount of NVRAM; and

reading data by performing the following;

receiving a read request;

accessing, in response to the read request, the stored logging record; and

recovering data associated with the stored logging record.

12. The non-transitory storage medium as recited in claim 11, wherein recovering data associated with the stored logging record comprises either recovering data included in the stored logging record, or recovering data based on logical data included in the stored logging record.

13. The non-transitory storage medium as recited in claim 11, wherein the first logging record is a physical logging record, and the second logging record is a logical logging record.

14. The non-transitory storage medium as recited in claim 11, wherein the NVRAM is allocated on a namespace basis.