filesystems over 200GB in size

[Ken Pannell]

I am running HPUX 11.11 with jfs filesystems. The biggest filesystem I have created up to this point is 100 gb, but we are thinking of creating filesystems 200 gb or larger for our SAP environment. The storage is on an EMC array. Does anyone know of any performance considerations in creating larger filesystems?

[A. Clay Stephenson · Accepted solution]

Large filesystems of themselves are not a performance problem -- and 200GB is not really considered large these days. The "gotcha's" are many files in a few directories just as in smaller filesystem; also the typical backup "object" for backup systems like DataProtector is the filesystem so backup performance will be negatively impacted because 2 100GB filesystems would get 2 disk agents whereas 1 200GB filesystem would get 1 disk agent.

[HGN]

Hi

A filesystem > 200GB is normal these days, in our environment we have filesystems in TB. There will not be any performance issue from the size of the filesystem standpoint.
There might be other contraints like taking backup & stuff like that no known issues.

Rgds

HGN

[Uday_S_Ankolekar]

Online JFS(3.5) can now support upto 12 TB of file system and Max 2TB of a file size, considering this, creating 200G file system should not give any performance issue.

-USA..

[Peter Unger]

lvol itself is not problem to have bigger than 200GB. We are also using such big FS. just don't forget to make a kind of load balancing. split the 200GB or 1TB what ever in enough PV's and with smaller Size than 100GB :D

Let's say create 40GB LUNs [5 of them] and from these LUNs/PV's create one 200GB lvol. and distribute them between 2 FC cards. makes your life easier. :D

[David de Beer]

And don't forget to set your PV's and LV's to max AND your extent size.

MAX extents : 65535

(Rounded figures)
4MB extents : max FSSize +- 256GB
8MB extents : max FSSize +- 512GB
16MB extents : max FSSize +- 1TB
32MB extents : max FSSize +- 2TB
64MB extents : max FSSize +- 4TB

etcetera.

David de Beer.

[S.Rider]

We have some big filesystems also, and the only big issue is backup performance. Like it was mentioned earlier, Omniback/DataProtector single-threads a filesystem to a single device. We got around this limitation on some of the biggies because they had been setup with a good sub-directory structure that made it pretty easy to split up the backups to multiple devices. But in some cases, there was a big old filesystem with millions of files that we couldn't split up. So those backups go to a single device and take forever.