讀gfs2官方文檔

reading link:

https://access.redhat.com/documentation/en-US/Red_Hat_Enterprise_Linux/7/html/Global_File_System_2/ch-overview-GFS2.html#s1-ov-newfeatures-GFS2

特色

1. Red Hat does not support using GFS2 for cluster file system deployments greater than 16 nodes.
   

2. However, the current supported maximum size of a GFS2 file system for 64-bit hardware is 100TB.

3. The current supported maximum size of a GFS2 file system for 32-bit hardware is 16TB

4. Asymmetric cluster configurations in which some nodes have access to the shared storage and others do not are not supported.

5. The rule of thumb with GFS2 is that smaller is better: it is better to have 10 1TB file systems than one 10TB file system.

6. With GFS2, you can add journals on the fly.

7. While there is no defragmentation tool for GFS2 on Red Hat Enterprise Linux, you can defragment individual files by identifying them with the filefrag tool, copying them to temporary files, and renaming the temporary files to replace the originals.

8. Newer versions of GFS2 include the fallocate(1) system call, which you can use to preallocate blocks of data

9. Red Hat recommends that you allow a period of around 8-12 weeks of testing on new installations in order to test the system and ensure that it is working at the required performance level.

10.    Mount Options: noatime and nodiratime

11. Security Enhanced Linux (SELinux) is highly recommended for security reasons in most situations, but it is not supported for use with GFS2.

12. Setting Up NFS Over GFS2

13. Samba (SMB or Windows) File Serving Over GFS2

14. Red Hat performs most quality, sanity, and performance tests on SAN storage with Fibre Channel interconnect

15. Suspending Activity on a File System

16. reltime
    

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軟件包

根據文檔一步步走，應該問題不大。 須要注意將lvm的鎖類型lock_type=1改爲3，表示集羣鎖！

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與ocfs2相比，一點感受而已：

- 這篇文檔寫得不錯，多了性能和調試相關的話題，說的比較接地氣；

- 易用性不如ocfs2;

- 限制多，gfs2說最多支持16結點，ocfs2說能支持64個結點； ocfs2的本地模式很方便； ocfs2的工具集組織，命名都比較正規，gfs2亂七八遭；

- ocfs2自帶原生DLM，即o2cb， 也支持dlm;

- gfs2貌似只有紅帽在玩，而ocfs2有oracle，SUSE， 華爲，華三幾個公司在玩；