This topic describes VMware Tanzu GemFire disk store file names and extensions.
Disk store files include store management files, access control files, and the operation log, or oplog, files, consisting of one file for deletions and another for all other operations.
The next tables describe file names and extensions; they are followed by example disk store files.
File Names
File names have three parts: usage identifier, disk store name, and oplog sequence number.
First Part of File Name: Usage Identifier
| Values | Used for | Examples |
|---|---|---|
| OVERFLOW | Oplog data from overflow regions and queues only. | OVERFLOWoverflowDS1_1.crf |
| BACKUP | Oplog data from persistent and persistent+overflow regions and queues. | BACKUPoverflowDS1.if, BACKUPDEFAULT.if |
| DRLK_IF | Access control - locking the disk store. | DRLK_IFoverflowDS1.lk, DRLK_IFDEFAULT.lk |
Second Part of File Name: Disk Store Name
| Values | Used for | Examples |
|---|---|---|
| <disk store name> | Non-default disk stores. | name=“overflowDS1” DRLK_IFoverflowDS1.lk, name=“persistDS1” BACKUPpersistDS1_1.crf |
| DEFAULT | Default disk store name, used when persistence or overflow are specified on a region or queue but no disk store is named. | DRLK_IFDEFAULT.lk, BACKUPDEFAULT_1.crf |
Third Part of File Name: oplog Sequence Number
| Values | Used for | Examples |
|---|---|---|
| Sequence number in the format _n | Oplog data files only. Numbering starts with 1. | OVERFLOWoverflowDS1_1.crf, BACKUPpersistDS1_2.crf, BACKUPpersistDS1_3.crf |
File Extensions
| File extension | Used for | Notes |
|---|---|---|
| if | Disk store metadata | Stored in the first disk-dir listed for the store. Negligible size, not considered in size control. |
| lk | Disk store access control | Stored in the first disk-dir listed for the store. Negligible size, not considered in size control. |
| crf | Oplog: create, update, and invalidate operations | Pre-allocated 90% of the total max-oplog-size at creation. |
| drf | Oplog: delete operations | Pre-allocated 10% of the total max-oplog-size at creation. |
| krf | Oplog: key and crf offset information | Created after the oplog has reached the max-oplog-size. Used to improve performance at startup. |
Example files for disk stores persistDS1 and overflowDS1:
bash-2.05$ ls -tlr persistData1/
total 8
-rw-rw-r-- 1 person users 188 Mar 4 06:17 BACKUPpersistDS1.if
-rw-rw-r-- 1 person users 0 Mar 4 06:18 BACKUPpersistDS1_1.drf
-rw-rw-r-- 1 person users 38 Mar 4 06:18 BACKUPpersistDS1_1.crf
bash-2.05$ ls -tlr overflowData1/
total 1028
-rw-rw-r-- 1 person users 0 Mar 4 06:21 DRLK_IFoverflowDS1.lk
-rw-rw-r-- 1 person users 0 Mar 4 06:21 BACKUPoverflowDS1.if
-rw-rw-r-- 1 person users 1073741824 Mar 4 06:21 OVERFLOWoverflowDS1_1.crf
Example default disk store files for a persistent region:
bash-2.05$ ls -tlr
total 106
-rw-rw-r-- 1 person users 1010 Mar 8 15:01 defTest.xml
drwxrwxr-x 2 person users 512 Mar 8 15:01 backupDirectory
-rw-rw-r-- 1 person users 0 Mar 8 15:01 DRLK_IFDEFAULT.lk
-rw-rw-r-- 1 person users 107374183 Mar 8 15:01 BACKUPDEFAULT_1.drf
-rw-rw-r-- 1 person users 966367641 Mar 8 15:01 BACKUPDEFAULT_1.crf
-rw-rw-r-- 1 person users 172 Mar 8 15:01 BACKUPDEFAULT.if
