"USB-Sticks" Vs. SD Cards

[arunagirinathar]

Hello All,

"Namaste".


I just went through this post at

http://c-mobberley.com/wordpress/2013/0 ... o-usb-hdd/

and also a similar howto at

http://elinux.org/Transfer_system_disk_ ... _hard_disk

basically the earlier post mentions that USB "Thumb-drives" are less prone to FS corruption as compared to SD Cards.

Either I have read/understood it wrong, or there is some tech fundamental (that I am yet to learn of) that makes SD-cards different from USB Thumb-drives ??

I assume that at the physical layer since both use NAND-Chips, there should not be much difference in the way data is physically stored or retrieved (?).

So what makes USB-Thumbdrives more resilient to FS-Corruption than SD Cards, Especially during Power-failures during a read / write operation ?

Thank you.

Regards,
SRK.

[RaTTuS]

no - it will be down to power / bad connections or bad kama
see

http://media.ccc.de/browse/congress/201 ... _xobs.html

for stuff about flash memory

[redhawk]

basically the earlier post mentions that USB "Thumb-drives" are less prone to FS corruption as compared to SD Cards.

My experience with memory cards have been the reverse except for maybe SmugMedia I guess it's all down to luck as they all essentially use the same technology though.
My Micro SD card in the Pi is well over 2 years old and showing no signs of wear damage yet, I also have other fully functioning SD cards and MagicGate sticks too.
As for USB memory sticks 2 have gone bad on me (cheap and nasty ones from Argos) and several other branded sticks that I have copied files with Windows only to find the next day they won't show the root folder.
Then there's SmartMedia - probably the worse memory card I've ever used in a digital camera.

Richard S.

[arunagirinathar]

Hello,

I am currently watching that "interesting" video on Youtube ...

Will get back after that.

[arunagirinathar]

Thanks for the link; very illuminating; CF, SD, ... all NAND Based Storage technology is simply not very reliable.

[arunagirinathar]

I was just wondering...

Would it be any good to connect a good-old 5400 RPM 3.5" HDD to a through a USB External Case; mount the entire root FS (except the FAT16 Bootloader; since pi can only book from SD ) on that ... ?

In terms of performance it would most likely be much slower than SD or a "thumb-drive"; but I am sure, it would be much more reliable; albeit at being less Mobile and consuming more power .... ??

[RaTTuS]

Thanks for the link; very illuminating; CF, SD, ... all NAND Based Storage technology is simply not very reliable.

well yes and no .. it all depends

[DougieLawson]

Use a USB2.0 2.5" enclosure with a SATA disk. That's going to be most reliable and give best possible performance (I'm ignoring SSD drives).

You will suffer from the SMSC9514 ethernet/USB controller being a bottleneck but it's probably going to be as good as running from an SDCard for the rootfs.

YMMV

[RaTTuS]

Use a USB2.0 2.5" enclosure with a SATA disk. That's going to be most reliable and give best possible performance (I'm ignoring SSD drives).

You will suffer from the SMSC9514 ethernet/USB controller being a bottleneck but it's probably going to be as good as running from an SDCard for the rootfs.

YMMV

^WHS
2 of my RPI's have proper HD attached - BIG space and rootfs moved onto them - they seem faster in use and no issues

[gkreidl]

I was just wondering...

Would it be any good to connect a good-old 5400 RPM 3.5" HDD to a through a USB External Case; mount the entire root FS (except the FAT16 Bootloader; since pi can only book from SD ) on that ... ?

In terms of performance it would most likely be much slower than SD or a "thumb-drive"; but I am sure, it would be much more reliable; albeit at being less Mobile and consuming more power .... ??

No, it's definitely faster, especially when it comes to writing lots of small files. rpi-update, for example, runs three times (estimated) as fast as it does when using a SD card. I've got a very stable system with high overclock rates; read/write to an EXT4 formatted HD is between 25 and 29 MBytes/sec. since I moved the roos FS to HDD.

[arunagirinathar]

Hello all,

Thanks for the great feedback !

I have an old 40GiG 5400RPM Disk from circa 2002 lying around (and it's mostly good). Will simply use it. My main use is a LAMP setup.

Thanks again.

[Richard-TX]

What really works well on a Rpi is a small solid state drive and USB adapter. The drive draws almost no current compared to a standard HDA. I am building a RPI development station and a SSD is a key part of that.

[RaTTuS]

What really works well on a Rpi is a small solid state drive and USB adapter. The drive draws almost no current compared to a standard HDA. I am building a RPI development station and a SSD is a key part of that.

my media server RPi is a 128GB SSD + USB to SATA adapter and an old RPi [256MB] - it's root partition is on the SSD.