Using stride on non-RAID
David Shaw
dshaw at jabberwocky.com
Wed Mar 16 18:02:34 UTC 2011
On Mar 15, 2011, at 6:53 PM, Eric Sandeen wrote:
> On 3/15/11 5:42 PM, David Shaw wrote:
>> Hello,
>>
>> I understand the need for a proper stride setting when formatting a
>> filesystem on a RAID device. However, is there any problem in using
>> a stride setting when formatting a filesystem on a regular non-RAID,
>> non-SSD, just plain-vanilla-single-disk block device? I'm sure there
>> isn't any benefit to it, but I'm curious if there is any harm.
>>
>> The reason I ask is I'm looking at some code here that can be used on
>> either RAID or non-RAID devices. The stride setting it has is
>> correct for the particular RAID setup it is intended for, but it also
>> uses those settings when formatting a non-RAID device.
>>
>> David
>
> just FWIW, recent kernels & e2fsprogs will just automatically pick
> stride based on storage geometry - for md/lvm at least, and for
> scsi devices that export this geometry as well.
>
> ext4 has a little stripe-awareness in its allocator; otherwise, stride
> just staggers bitmap starts so they don't all end up on the same spindle; [1]
> Offhand I don't think it'd cause any harm to set stride on non-raid.
Thanks very much for your pointers. It's a nice enhancement that this is done automatically now.
David
More information about the Ext3-users
mailing list