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Best way to set up a high availability server?

Started by RobertM, 2008.08.15, 02:50:30

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RobertM

    Hello all,

    Yeah, I am full of questions this week... so, thanks in advance to everyone who has been answering them all in various threads. Below are a few new ones:




JFS Options and Capabilities?


I was reading this article on Wikipedia:
http://en.wikipedia.org/wiki/IBM_Journaled_File_System_2_(JFS2)

RE: Capabilities and File System Options for JFS on OS/2

Which brought up a question regarding this part of the article:
QuoteConcurrent Input / Output (CIO)

JFS normally applies read-shared, write-exclusive locking to files, which avoids data inconsistencies but imposes write serialization at the file level. The CIO option disables this locking. Applications such as relational databases which maintain data consistency themselves can use this option to largely eliminate filesystem overheads.

I am presuming from the fact that this Wiki page is for the OS/2 version of JFS (unless is it possibly referring to an updated AIX version? Someplace I heard that JFS/2 was ported back to AIX as JFS2)...



  • If this article is accurate, does anyone know how to enable the CIO option?
  • Is that smart or beneficial?
  • I presume it would also help with web serving? (Since often, the same file is opened a few dozen times at once).
  • If I enabled CIO (assuming it's possible) are there certain things I should not use or do on the drive?


The key thing would be to improve database access performance of MySQL v5.




JFS and HPFS386 Maximum and Practical Cache Sizes?


Final question. It seems that increasing one of the disk caches I am setting for my file systems (HPFS386 and JFS) is using a chunk of the shared memory arena.


  • Does anyone know if both disk caches use that arena, and if neither do, why it seems to cause problems?
  • Also, suggestions on a cache size to use would be appreciated.

Right now, they are both set at "low" levels (128MB for JFS, 64MB for HPFS386).I need to leave at least 2000 threads available for Domino GoWebserver (with enough to spare for the OS and the other server processes). Setting MAXTHREADS to 2000 or more with high disk caches seems to crash the system.


As this system is an active server, I cant play with it to determine if either or both file system caches are the cause.





Specifics and more details below... dunno how much is helpful or not:



The machine has 4GB of RAM, and runs the following server processes:

  • FTP (Pete Moylan's FTPd v1.30)
  • Web (Lotus Domino GoWebserver v4.6.2.8)
  • MySQL (Paul Smedley's port, v5.0.51 - to be upgraded to latest soon)
  • Zeryx's ZxMail (v1.2.19)
  • WSeB Domain Controller (WSeB v4.52 CP2 PF)




Other details that may be relevant

  • The machine has 3 logical drives (U160 RAID 1E, each logical drive striped and mirrored using all four physical disks)
  • The machine has an 8GB HPFS386 boot partition
  • The machine has a 40GB HPFS386 Apps/Data partition
  • The machine has a 240GB JFS partition (MySQL and FTPd are running entirely from this drive)
  • Web documents (for LDGW) are stored on the 40GB and the 240GB partitions.
  • All FTP accounts/folders are on the JFS partition.




Thanks in advance,
Robert

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Fahrvenugen

#1
Just to comment, I know you don't want to do much "experimenting" with this machine due to the fact that it needs to be available, but...

The one thing I've run into with HPFS386 over the years is that when its cache is set higher then 64 MB, on some machines I've actually seen slower performance when the cache is set to 65 MB or higher.  And on some other machines there's no problem cranking the cache up higher.  I have not figured out why.  Two systems in particular that I've done testing on showed a performance hit as soon as I increase the cache to 65MB (or higher) and the same machines fly at 64 MB.

I have not seen the same issue with JFS, so if I were going to play with cache sizes to try and improve performance, I'd start with the JFS cache.

Don't know if this helps.

Ben

RobertM

I see that you're using Lotus Domino GoWebserver v4.6.2.

I used it a long time ago and liked it.

I'm considering re-installing it as a replacement for Apache/2. Not that there is anything wrong with it, but I prefer to use OS/2 based software for the obvious performance benefits.

A few questions, if you'd be so kind...

Is there a problem using current level PHP? or mySQL? or with using current hardware? I'm presently using an AMD 2200+ w/ 1.5 gig on eCS 2.0 rc4 without a problem.

Five forums, eight websites six of which are virtual.

I'm also wondering about the advantages of using WSeB Domain Controller, which I have, but have never installed.

Any caveats would be appreciated.

Thank-you.