topic Re: filesystem in Operating System - HP-UX

filesystem

sanmukh — Sun, 25 Feb 2007 02:07:39 GMT

what is main difference between HFS and VXFS filesystem?

Re: filesystem

Mridul Shrivastava — Sun, 25 Feb 2007 02:46:44 GMT

High-Performance File System (HFS)

HFS represents HP-UXâ s standard implementation of the UNIX File System (UFS). HFS file systems reside on mass storage devices, usually hard disk drives. Prior to HP-UX Release 10.01 this was HPâ s only disk-based file system. HPâ s long term strategy is for JFS to become the default and for HFS to continue to exist for compatibility.

Journaled File Systems (JFS)

The HP-UX Journaled File System, also known as Veritas File System (VxFS), is an extent-based journaling file system which offers fast file system recovery and on-line features such as on-line backup, on-line resizing and on-line reorganization. An intent log contains recent file system data structure updates. After a failure the system checks the intent log and
performs the required rollback or roll forward.

There are two JFS products, base and online. The base JFS file system has the fast recovery feature and is included in all 10.01 and later systems. Online JFS, also referred to as Advanced VxFS is an optional product that adds extensions to JFS. It offers these additional capabilities:
â ¢ online defragmentation and reorganization
â ¢ online expansion and contraction of file system size
â ¢ online backup

Re: filesystem

Steven E. Protter — Sun, 25 Feb 2007 02:58:58 GMT

Shalom,

HFS is required to boot systems HP-UX 11.11 and before. It used to be the standard.

vxfs is licensed from Veritas, and is a journaling filesystem. It handles sudden problems and errors in a very robust way. Its very hard to lose data on such a filesystem so long as the underlying disk is good.

SEP

Re: filesystem

A. Clay Stephenson — Sun, 25 Feb 2007 14:57:15 GMT

HFS is essentiqally the same as the old Berkeley ufs filesystem --- and while it was a huge improvement over the old System V filesystem, it is still block-based and offers poorer performance than the Veritas filesystem. The "main" difference is that the hfs filesystem is block-based whereas the vxfs filesystem is extent-based. This means that the vxfs filesystem always tries to write in large chunks (extents) and that block size has no bearing upon performance (unlike the impact of block size in hfs/ufs filesystems).

Re: filesystem

sanmukh — Fri, 02 Mar 2007 01:00:17 GMT

I m closing this thread.