Editing GFS2 (section)

{{Short description|Shared-disk file system for Linux computer clusters}}
{{redirect|Global File System|the general concept|Global file system}}
{{Infobox filesystem
| name = GFS2
| developer = [[Red Hat]]
| full_name = Global File System 2
| introduction_date = 2005
| introduction_os = [[Linux kernel|Linux]] 2.6.19
| partition_id =
| directory_struct = Hashed (small directories stuffed into inode)
| file_struct = bitmap (resource groups)
| bad_blocks_struct = No
| max_file_size =
| max_files_no = Variable
| max_filename_size = 255 bytes
| max_volume_size =
| dates_recorded = attribute modification (ctime), modification (mtime), access (atime)
| date_range =
| date_resolution = Nanosecond
| forks_streams =
| attributes = No-atime, journaled data (regular files only), inherit journaled data (directories only), synchronous-write, append-only, immutable, exhash (dirs only, read only)
| file_system_permissions = Unix permissions, [[Access Control List|ACLs]] and arbitrary security attributes
| compression = No
| single_instance_storage = across nodes only
| encryption = No
| OS = Linux
| filename_character_set = All except [[Null character|NUL]]
}}
{{Infobox filesystem
| name = GFS
| developer = [[Red Hat]] (formerly, [[Sistina Software]])
| full_name = Global File System
| introduction_date = 1996
| introduction_os = [[IRIX]] (1996), [[Linux kernel|Linux]] (1997)
| partition_id =
| directory_struct = Hashed (small directories stuffed into inode)
| file_struct = bitmap (resource groups)
| bad_blocks_struct = No
| max_file_size =
| max_files_no = Variable
| max_filename_size = 255 bytes
| max_volume_size =
| dates_recorded = attribute modification (ctime), modification (mtime), access (atime)
| date_range =
| date_resolution = 1s
| forks_streams =
| attributes = No-atime, journaled data (regular files only), inherit journaled data (directories only), synchronous-write, append-only, immutable, exhash (dirs only, read only)
| file_system_permissions = Unix permissions, [[Access Control List|ACLs]]
| compression = No
| single_instance_storage = across nodes only
| encryption = No
| OS = [[IRIX]] (now obsolete), [[FreeBSD]] (now obsolete), [[Linux kernel|Linux]]
| filename_character_set = All except NUL
}}

In [[computing]], the '''Global File System 2''' ('''GFS2''') is a [[clustered file system#Shared-disk file system|shared-disk file system]] for [[Linux]] computer clusters. GFS2 allows all members of a cluster to have direct concurrent access to the same shared [[block storage]], in contrast to [[clustered file system#Distributed file systems|distributed file systems]] which distribute data throughout the cluster. GFS2 can also be used as a local file system on a single computer. 

GFS2 has no disconnected operating-mode, and no client or server roles. All nodes in a GFS2 cluster function as peers. Using GFS2 in a cluster requires [[#Hardware|hardware]] to allow access to the shared storage, and a lock manager to control access to the storage.
The lock manager operates as a separate module: thus GFS2 can use the [[distributed lock manager]] (DLM) for [[cluster (computing)|cluster]] configurations and the "nolock" lock manager for local filesystems. Older versions of GFS also support GULM, a server-based lock manager which implements redundancy via failover.

GFS and GFS2 are [[free software]], distributed under the terms of the [[GNU General Public License]].<ref>
{{Cite journal
|title = Symmetric Cluster Architecture and Component Technical Specifications
|url = http://people.redhat.com/~teigland/sca.pdf
|first = David|last = Teigland
|date = 29 June 2004
|access-date = 2007-08-03
|publisher = Red Hat Inc
}}
</ref><ref>
{{Cite journal
 |last1       = Soltis
 |first1      = Steven R.
 |last2       = Erickson
 |first2      = Grant M.
 |last3       = Preslan
 |first3      = Kenneth W.
 |title       = The Global File System: A File System for Shared Disk Storage
 |url         = http://www.diku.dk/undervisning/2003e/314/papers/soltis97global.pdf
 |journal     = IEEE Transactions on Parallel and Distributed Systems
 |year        = 1997
 |url-status     = dead
 |archive-url  = https://web.archive.org/web/20040415075825/http://www.diku.dk/undervisning/2003e/314/papers/soltis97global.pdf
 |archive-date = 2004-04-15
}}
</ref>