which file system to use

[Tom Smith]

Alexander Skwar wrote:

>David Abrahams <dave at boost-consulting.com>:
>
>  
>
>>Alexander Skwar <listen at alexander.skwar.name> writes:
>>
>>    
>>
>>>John L Fjellstad <john-ubuntu at fjellstad.org>:
>>>
>>>      
>>>
>>>>Alexander Skwar <listen at alexander.skwar.name> writes:
>>>>
>>>>        
>>>>
>>>>>The commit is not (only) because of atime. ext3 will commit to
>>>>>disk, even if *nothing* has been accessed.
>>>>>
>>>>>That said, laptop-mode is a good suggestion.
>>>>>          
>>>>>
>>>>Looking at the mount options for ext3, there is a commit option
>>>>(although the default is set to 5 sec, so I'm not sure it's that which is
>>>>causing the disk access).  If it is the cause of the disk access, I
>>>>would think changing this option to something else (60 sec or whatever),
>>>>might help.
>>>>        
>>>>
>>>Well - turning on/off the hd every 60 seconds isn't *THAT* much
>>>better, is it? ;) I'd rather set it to 1 hour, or so. BUT: If
>>>the system crashes, you'll lose the not yet written data. Ie.
>>>up to 1 hour would be lost.
>>>
>>>Because of this and because of the slowness, I'd not suggest ext3
>>>but rather JFS.
>>>      
>>>
>>[I have a couple of machines (a laptop and a server) with fresh
>>installs on ext3, and at least one of them probably needs a full
>>reconfiguration, so I'm following this thread with great interest.]
>>
>>Two questions:
>>1. Does JFS always commit immediately?
>>    
>>
>
>I don't know for sure, but I don't think, it'll commit *immediately*.
>This would be bad performancewise, I'd think. I'd suspect, that it,
>let's say, "groups" together requests, so that the disk access can
>be minimized.
>  
>
Alex, if JFS doesn't commit "immediately", *then that is not a valid 
reason to use it on a laptop versus using ext3*--the same problems would 
likely exist with either file system and, for that matter, probably with 
any file system... This is especially true if, as you pointed out, file 
system performance issues would result from "immediate commits".