Re: ASM vs ACFS for 18.7 on X8-2M ODA

From: Mladen Gogala <>
Date: Fri, 13 Dec 2019 20:06:04 -0500
Message-ID: <>

Hi Jack!

ACFS is a cluster file system which runs on top of a cluster volume manager, namely ASM. Most of other, competing cluster file systems like GPFS, GFS or NTFS run on top of a cluster volume manager. File system is much more practical than volume manager devices because you can use OS utilities like tar, cp, find or ls. The price you pay for that practicality is another software layer on top of the volume manager. The main reason for abandoning OCFS2 was the fact that it was open source and could have potentially been used by competitors. Bill Long, the author of the first and only ASM book that I am aware of, has explicitly said so in his book. ACFS is a completely proprietary file system and such danger doesn't exist. I have tested ACFS on version 12.2 and have yet to rebuild my cluster on the version 19.5. Version 18c is a dead end and I wouldn't use it without having a very good reason.

As far as the cluster file systems go, ACFS is a very decent one and performs really well. The performance penalty you pay is not steep and you get the versatility of an excellent cluster file system. I am all for ACFS.


On 12/13/19 3:13 PM, Jack Applewhite wrote:
> We just got our two new X8-2M ODAs installed and are debating whether
> or not to use ACFS. We had to do so on the X5s we're migrating from,
> but I never have liked the idea of the ACFS layer on top of ASM,
> especially for DB files. I've looked back and found various arguments,
> but they seem tied to more-or-less specific architectures. These X8s
> are standalone, bare metal, non-HA servers, so none of the RAC-ready
> junk we had to deal with in the X4s and X5s.
> I'm pushing for only ASM for DBs, but maybe an ACFS filesystem for
> regular OS files.
> What are some experiences, recommendations, pointers for us to consider?
> Thanks.
> --
> Jack C. Applewhite - Database Administrator
> Austin I.S.D. - MIS Department
> 512.414.9250 (wk)
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Mladen Gogala
Database Consultant
Tel: (347) 321-1217

Received on Sat Dec 14 2019 - 02:06:04 CET

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