RAID on SD

[kattle87]

Just crazy idea

What if we were able to "spread" some files on the SD and the internal memory or on both the SDs (not the best idea of ever) so we can get some kind of "raid" behaviour to speed up loading times? Sometimes Class 4 SDs are not the fastest thing on earth, and afaik Class 6 are more expensive

 

[mkinzler]

I don't think that this would be possible. And if the speed gain wouldn't great.

 

[Catch23]

Actually, as far as I know, Linux software RAID will work on any block devices. This means that you can use the SD cards to make some kind of RAID array. It depends on how the buses works as to whether you would actually get a performance benefit though.

 

[mali]

There was already an extensive discussion about it, I don't know if it was here or on gp32x. The bottom line was, it isn't worth it.

 

[saejinoh]

i'm no computer expert, but i doubt raid will benefit flash drives like it does to magnetic drives.

plus 600mhz, while blazingly fast for a handheld device, probably isn't fast enough to take advantage of dual read/write speed.

 

[Spectralist]

Raid0, if i am not mistaken, is largely useful for speeding up seek times. Seek times are already excellent for flash memory.

 

[Etinin]

I'm doing it, it'll probably still increase write speeds.

 

[mindlord]

I'm doing it, it'll probably still increase write speeds.

Have fun wasting your time. Seriously.... It will not improve anything. Even worse it may slow things down.

 

[truekaiser]

There was already an extensive discussion about it, I don't know if it was here or on gp32x. The bottom line was, it isn't worth it.

correct. with only two sdhc devices, you could only use raid 0. making both of them look like one large device but if either one fails you lose data on both of them. if you do raid 3 with the two sdhc cards and the internal memory your nice large sdhc cards will be limited to the size of the internal memory. Raid was designed for server's it's too much of a hassle for non-server usage.

 

[Hotcooler]

Actually I'd like to use RAID-0. I just like it. And if one fails... I dont care... All data will be backed up on PC. No valuable data will be on the cards. So I just dont care. Plus I never saw a SD card that failed. Maybe I'm just lucky . But people you care too much about your data.. I bet you will never have something REALLY valuable on there?

 

[Spectralist]

with only two sdhc devices, you could only use raid 0.

You could do Raid1 as well, but i doubt anyones seriously interested in that.

 

[mkinzler]

He wants to speed up the access. Raid-1 only brings security

 

[truekaiser]

with only two sdhc devices, you could only use raid 0.

You could do Raid1 as well, but i doubt anyones seriously interested in that.

besides raid-1 is not technically raid, but just disc mirroring.

 

[phrosty]

raid-1 could improve read speed, just not write speed.

besides raid-1 is not technically raid, but just disc mirroring.

what gave you that idea?

 

[VRAndy]

Actually I'd like to use RAID-0. I just like it. And if one fails... I dont care... All data will be backed up on PC. No valuable data will be on the cards. So I just dont care. Plus I never saw a SD card that failed. Maybe I'm just lucky . But people you care too much about your data..

Doing this would also stop you from using one slot as a 'ferry' to move files to and from other devices.

I really don't think this would improve performance, anyway. Not on random-access storage like an SD card.

I bet you will never have something REALLY valuable on there?

Loss of saved games is the only thing that makes me violent towards technology.

 

[Etinin]

I could just make some script to automatically backup my Pandora to my computer every night while I'm sleeping or something.

 

[hkipp]

Whilst we're at it, will ZFS be available as well? Oh, and I'd love to run Oracle and SAP, too. :lol:

Seriously, if speed is that important for you, get a decent (6) SD-Card.
If you need raid 1 or 5, why not partition the SD-card to provide 4 partitions, so you don't need two cards.

 

[Tom`]

As has been stated several times, RAID 0 will give no appreciable speed increase, for two reasons: it will not improve seek times, because SD seek times are virtually nonexistent anyway, and striping will not improve write performance, because both SD cards cannot be written at the same time.