default file system, was: Comparison to Workstation Technical Specification

[Chris Murphy]

On Mar 1, 2014, at 5:44 PM, Reindl Harald <h.reindl at thelounge.net> wrote:

> 
> 
> Am 02.03.2014 01:36, schrieb Chris Murphy:
>> On Mar 1, 2014, at 4:51 PM, Reindl Harald <h.reindl at thelounge.net> wrote:
>> 
>>> Am 02.03.2014 00:42, schrieb Chris Murphy:
>>>> 
>>>> On Mar 1, 2014, at 4:26 PM, Chris Murphy <lists at colorremedies.com> wrote:
>>>> 
>>>>> 
>>>>> On Mar 1, 2014, at 2:16 PM, Matthew Miller <mattdm at fedoraproject.org> wrote:
>>>>> 
>>>>>> On Fri, Feb 28, 2014 at 11:29:30PM -0700, Chris Murphy wrote:
>>>>>>> - There needs to be a mandate to remove features from custom partitioning
>>>>>>> that quite frankly don't make sense like rootfs on raid4, raid5 or
>>>>>>> raid6. OK maybe raid5. But not raid 4 or raid 6. There are other
>>>>>> 
>>>>>> Okay, I'll bite. Why not rootfs on raid6?
>>>>> 
>>>>> It's pathological. There are too many simpler, faster, more resilient options considering rootfs at most isn't bigger than the average SSD: Two or three SSDs + n-way mirroring. RAID 10. Or RAID 1 + linear + XFS for deterministic workloads.
>>>> 
>>>> Those three examples are simpler, more resilient, easier to configure and maintain, perform better, with faster rebuild times than RAID 6 which also has a high read-modify-write penalty. I left that part out.
>>> 
>>> yes, but RAID6 allows a disk-fault *while* rebuild the RAID after the first one
>>> RADID 10 *may* do the same if the *right* second disk fails
>> 
>> If you need two disk failure tolerance use n-way mirroring with three disks, anaconda supports this
> 
> and if you need failure tolerance *and* performance?

You need better rootfs performance than what's provided by SSD?

> yes, then use commercial SAN storages…

OK, but it sounds expensive and demeaning. Yet, I'll grant that it's more sane than rootfs on software RAID 6.



Chris Murphy