yashsingh1/xdaforums huggingface dataset:
[Android General] NYLimited:
I have heard of people having difficulty formatting cards of most brands - nothing specific to Kingston. While Kingston came in slower on tests than SanDisk that should not prevent it from being formatted correctly unless the card itself is bad or damaged.

If you don't already have it, install a copy of Minitool available free

here

and make sure that your FAT32 partition is created as the first one, the ext4 as second. Both of them should be set as primary.

Before doing the partitioning steps from above use SD Formatter on the card. After it finished take a look at the cluster size it set for you - that will be the ideal cluster size for the card most likely. Use that cluster size in step 1 above.

As for the buffers - experimenting will give you the best performing one. I do not recommend setting it too small but it should be easy enough (though a little time consuming) to try different ones. You might want to start with 8192KB or 4096KB and go up and down from there till you find the best one for your device.

[ edit ] Do not rely solely on benchmarks or test apps. The "feel" of your device is more important than a read/write test result although those are often indicative. :)

Interesting problem that I have not seen yet. Try to delete ALL partitions from the card (I am assuming you already backed it up or you do not need to) and have SD Formatter clean it up. Once you get the full size back use Minitool to create your primary partitions again.

Hope this helps a little. Let us know how you make out.
[Android General] Lownita:
Yes, that's it! :o
[Android General] NYLimited:
I wouldn't worry about that - some day the app will be updated to include these 'new' cards and their names. :fingers-crossed:
[Android General] rsngfrce:
I was directed to this very informative thread from an sd card question i posted in another forum here. What i would like to find out, and haven't seen covered here (unless i missed it) is if Android starts having issues with your sd card, is that a sure sign the card is going bad, or could this be caused by something else?

I am now expediencing this for the second time. The first time was with a 32gb Sandisk class 4 card. I started recieving notifications that my sd card might be damaged and need to be formatted. I would reboog and it would be fine. I beleive this card did have issues, because Windows Check Disk would sometimes find and correct problems when I checked with it.

About 2 months ago i replaced this card with a 64gb Sandisk class 10 (puchased on Amazon crom a reliable seller as far as I could tell). I have recently started receiving possible damage notifications about once per day. When I reboot, the card works fine. I have checked it with Check Disk several times and it never finds any issues. To be safe, i completely formatted the card using the GUI version of Fat32format (complete format, not quick). The next day, I received the possibly damaged notification again. A couple days ago i received a notification the the sd card had unexpectedly been removed from the phone, tben a few seconds later that the carx may be damaged (how it can tell this when it thinks the card is removed is beyond me). Today I received a notification that my card was blank or had an unknown file system. When I reboot, these issues are always gone until the next time they occur. So, is this a sure indication that the card is going bad, or could Android be falsely giving me these issues for some reason? Any advise is very much appreciated!
[Android General] NYLimited:
I mentioned a few of the recovery programs in

this post

back in July but a real discussion on data recovery could use a brand new topic I suspect. I may look at that option some time but at the moment I don't have enough time to do justice to a brand new topic. :(
[Android General] ramola:
I have 16GB as card after putting in phone it is showing blank ad card. After connecting to pc with ad card adapter it shows all data but every process like copy,cut,delete occurs very very slow. My pc, phone is unable to format it. Error occurs while formtting. Now what do do.or card is unusable.
[Android General] cajunflavoredbob:
Get a new card. That one is dying a slow death.
[Android General] NYLimited:
Or, at least try formatting it with SD Format... If that doesn’t help it is likely time for a new card.
[Android General] haxor:
Wanna buy SD card class 10 for my note 2 so which one will be best as all SD card having same spec though
[Android General] NYLimited:
I do not own the device so I may be off slightly but my personal preference is Sandisk or Samsung.

---

Any clod can have the facts, but having an opinion is an art.
[Android General] ramola:
I read in certain posts that class 6 card is better than class 10 for smartphones? Is it true? I was planning to buy class 10 transend or sandisk 32 gb sd card. Should I ?
[Android General] NYLimited:
The Class 6 card is not 'better' than a Class 10 technically.

The differences are created by different brands (some card brands seem to better than others) or by the mobile device itself (not all card buses are created equal).

Generally, older devices will function better (more reliably) with a slightly slower card, so he as Class 6. Newer devices are much faster and will likely function well with a fast, quality card.

Consult your device's recommendation for cards and go one step above.
[Android General] haxor:
Just bought Samsung 32 GB class 10 SD card its really reliable how can I check card data transfer rate is there any app for this purpose ?
[Android General] NYLimited:
There is an entire section on bench-marking your card in

post 1

.
[Android General] Topoignaz:
Benchmarks

Vellamo has been updated 10 days ago. It performs accurate tests on CPU and HTML5 capabilities of your device and it's still free.
[Android General] ramola:
I have ordered 32GB Samsung class 6 card for my lg optimus black on snapdeal, hope it will be good for my OB.
[Android General] NYLimited:
I was using Samsung Class cards for quite a while on my HD2 with excellent results.

I think they will likely work well for you. :)
[Android General] NYLimited:
Thanks for the info! I updated the original post. For those interested the app is now up to version 2.0.3 and has added

Compatibility with Android KitKat 4.4

Updated user Interface

Updated HTML5 Chapter including HTML5 Video, DOM performance, Web page load/reload, and WebGL

New Chapter focused on the CPU Metal with both industry standard and custom tests

Supports both ARM and x86 processors
[Android General] DiamondJohn:
Well, I now have a 64GB SD card in my phone that supposedly only supports 32GB:highfive: oh, and its working. The final trigger that solved it for me was this YouTube vid. http://www.youtube.com/watch?v=JA9fp863d-o It appears its npot a limikt of the phone or OS. but simply that you have to format the card somewhere else. I used MiniPartition Wizard free (I also have a swap partition in addition to 2 ext4 partitions)

I did NOT have to modify any system config files. However, I am actually creating an extra EXT4 partition in my specific case, and hence I have some init.d scripts to mount it at various loacations.

Ok, the traps for young players:

NOT ALL SDCARD READERS ARE COMPATIBLE WITH 64GB!!

If you create an extra partition (as I did) instead of a single large FAT32 partition, the media scanner wont find any files on the new partition. I had to put a mount with bind on the FAT32 (ie first partition) eg I have dir structure of /storage/sdcard0/mnt/sdext3 where sdext3 is my new 45GB EXT4 Partition (NB: sdext2 is being used by Link2SD)

Since I am on Win7, I could not read this big new partition. I actually created a bootable (4GB) usb stick, that loads a "live" version of Fedora, which has a file manager (and not much else) that can read/write FAT32 and EXT4. So all I have to do is not stick in this USB stick, reboot, and I am in unix to transfer my files. One thin I did notice, is that if the permissions are not set in Android, the folders/files become read-only (if you will even be able to read them)

EDIT

Below is the "meat and potatoes" of the scripts I created to create the various new mount points for my new partition. NB: if you dont create an extra partition, then you would not have to do the below. Also note, that the below is spread over a number of init.d scripts I have which include checks/waits for the sdcard to mount. NB: the below is not ready to run in your own Init.d, but should get you started.

busybox mkdir -p /data/sdext3;
busybox mkdir -p /storage/sdext3;
busybox mount -t ext4 -o rw /dev/block/mmcblk0p3 /data/sdext3
busybox mount -o bind -o rw /data/sdext3 /storage/sdext3
busybox mkdir -p /storage/sdcard0/mnt/sdext3
busybox mount -o bind /data/sdext3 /storage/sdcard0/mnt/sdext3;

I found some weird problems with the script above, so now I mount the new EXT4 partition under /storage/usbdisk and the standard media scanner process catches it in the boot. it early days yet, but when all my music was on the FAT32 sdcard, I noticed it would "skip" every now and then. I haven't notice the same now that all the MP3's are on the ext4 partition.

The new script with all my logging is attached.
[Android General] Ayan Uchiha Choudhury:
While using app manager three, it shows that my device has no real primary external sd card. So what should I do? How do I create a real primary external sd card?
[Android General] NYLimited:
Sorry, I don't think I follow the question.. Are you saying you have an SD card in the device, formatted and it is not showing?

---

Any clod can have the facts, but having an opinion is an art.
[Android General] Ayan Uchiha Choudhury:
No I mean that I've a 16 gb memory card. Now I've inserted it in my mobile and then I'm using app manager three so that i can move my installed apps to my memory card. However while I'm trying to use it, i find that it's showing that my mobile has no real primary external sd card. So i can't move my apps to my sd card. Please note that my phone is rooted. I really need help.
[Android General] NYLimited:
I cannot easily tell you what the problem is but obviously there is one.

Have you true formatting the card with SD Format to make sure it is clean and usable?

Try checking in another app like ES File Explorer to make sure the card can be seen. If it is visible the problem may be with the app you are using to move things.

---

Any clod can have the facts, but having an opinion is an art.
[Android General] Ayan Uchiha Choudhury:
Yaa it's visible. And thankx i learnt that i needed to partition my sd card 1st. I did it and then used link to sd. Problem solved. Thanks anyways. :)
[Android General] NYLimited:
Hey, you got it to work! Well done!

Happy New Year!

---

Any clod can have the facts, but having an opinion is an art.
[Android General] procter:
So I've seen a lot of conflicting opinions on the EXT partition size, quite a few older posts back in 2011-2012 claiming that you don't want the SD-ext partition size to be larger than 1Gb for 4Gb and larger cards, and yet here in OP and some other posts talking about 16 -32GB cards, the EXT partition was set at 1.5-3gb (some posts were saying if using ext3 format, the partition needs to be smaller than 2Gb)

All these claims did not provide any reasons, so now in 2014 and Android apps are getting larger and larger as well as the SD cards, are these limits still valid?

I followed the old claims and gave only 1Gb ext 4 partition on my 32Gb class 10 card in GS3, with not a single big game being installed, it already eats up 700 MB of that 1GB after I used link2SD.

Thanks a lot.
[Android General] NYLimited:
When I was using a card I had a 32GB Samsung with a 4GB ext4 partition. Never had any problems.

There is no reason I know of to restrict the partition size. Older devices, may have had problems, don't know. It certainly isn't a Linux or Android or file system restriction.

It should be simple to create a full image of the card and try a bigger partition.

Sent from my Nexus 4
[Android General] DiamondJohn:
I didn't see the posts. I am running KitKat, carbon ROM on an Xperia Ray 2011, with a 64GB Class 10 SD Card partitioned with 8GB Fat32, 2GB EXT4 for Internal data using Cron mod, a 50GB EXT4 data partition for my music and videos and a 300MB Linux swap partition. It seems to work pretty fast for me.

I set the mounts with "noatime,nodiratime,barrier=0"
[Android General] Capt Morpheous:
which one, why and how

Hello all.

I am new.

I aksing for your help to select a new micro sdhc (max. 32gb) card for an eight year olds (Fuhu) Nabi 2. I am in the U.K.

Seems there may have been a manufacturing change with the Sandisk 32gb class 4 cards (good 4k r/w), which has actually improved (not a typo) 4k performance if accurate:

w**.androidfornook.com/forum/archive/index.php?thread-1030.htm

&

w**.theatreofnoise.com/2013/08/choosing-micro-sd-card-for-your-phone.html

Technical Specs:

w**.nabitablet.com/nabi2/specs

Device was released in late 2012, so the i/o bus will be quite old. 8gb internal memory on device only.

Rooting (4.1.1) to run apps from a Mirco SDHC card.

I have searched through xda. There are many many crystalmark tests from 2011 to the end of 2012.

Now in 2014, I'm asking if anyone could recommend a card today that would be a good choice for:

Apps from SD (priority concern) - being a kid - he wants app after app.

720p video

Photos

My sincere thanks.

Capt Morpheous
[Android General] NYLimited:
I don't know the device so could not say if it has any limitations on the card bus speed. Considering that it is an old device I would hesitate to recommend a very fast, newer design card although it may actually work fine. I probably would try a Class 6 Samsung card. Not the fastest but it should work reliably.

Sent from my Nexus 7
[Android General] Ri9000:
a little more flash related partitioning info?

Dear Sir, thankyou for your very informative article. If i could expand a little on the topic..

flash media (nand flash and related) used as internal storage for our phones and tablets,

used to use yaffs2 and similar dedicated filesystems to manage their internal storage. The trend now seems to be to use ext4 a robust journalling hard-disk type filesystem.

Do you know if there is any valid reasoning behind this please? eg: Why not use whats designed for the job?

thanks.
[Android General] NYLimited:
A long story but... I think Google began to transition Android toward ext4 back around 2010 or so with the Nexus S.

Ted T'so, who played a key role in developing EXT4, was hired by Google. He said that he didn't influence the decision to use Ext4 in Android, but provided some advice and guidance to the Android team after the decision was made.

As you noted, most Android devices were using YAFFS, a lightweight filesystem that was optimized for flash storage and was commonly used in mobile and embedded devices. The problem with YAFFS, T'so explained in his blog entry, is that it is single-threaded and would likely "have been a bottleneck on dual-core systems." Concurrency is more important on Android devices that use multi-core ARM processors.

Btrfs, which was expected to eventually displace Ext4 simply wasn't mature enough at the time for use in production. Canonical considered using Btrfs as the default filesystem in Ubuntu 10.10, but also postponed adoption after similarly deciding that it needed more time in the oven.

Sent from my Nexus 7
[Android General] Ri9000:
thankyou for your informative reply.
[Android General] Dhruna:
Hi NYLimited,

recently i have purchased Toshiba's Class 10 SD card and using Tytung's V4.7 with Data on Ext. The ROM load the application very show.

I have used below partition structure

1st FAT 32 4+ GB (4kb cluster )

2nd EXT4 3.5 GB (4kb cluster)

Please suggest what is the best cluster size for EXT4.

i have test the FAT and getting 22+mbps read and 10+ write, but cannot check sd-ext with SD Tools.

Thanks in advance.
[Android General] NYLimited:
Did you use SDFORMAT first on the entire card?

Although you can experiment with different cluster sizes (which will, of course, wipe the card) the 4kb is probably ideal for both (your FAT32 partition us less than 8 gig and EXT4 defaults to 4kb). I would likely leave it as is unless just experimenting. Don't forget to set FAT32 read buffer in Android which can make a noticeable difference.

---

* Give a man a fish and you feed him for a day; teach a man to fish and you feed him for a lifetime.
[Android General] Dhruna:
Thank you NY,

I did not formatted the SD card using SDFormat, tool, will do that first and again make the partition. Will also change the FAT32 read buffer size.

by default it is set to 2048, is this fine, so should I increase it by 4096 or in multiple of 1024 ?

Thanks.
[Android General] NYLimited:
The read buffer is easy to change and takes effect immediately. Change it to something else and run a quick benchmark. Change it again and the run the benchmark again. That will, after a few tries, tell you which number is best for your card and device combination!
[Android General] Dhruna:
Hi NY,

I formatted the card using SDFormater and created fresh partition 5+GB (FAT32-4KB) and 2 GB (EXT4-4KB).

I restored the data and ran the SD Tools with below settings of /sys/devices/virtual/bdi/179:0/read_ahead_kb

read_ahead_kb | Write | Read

1024 | 7.2 | 17.2

2048 | 16.3 | 19.7

3072 | 10.7 | 22.3

4096 | 10.6 | 21.3

8192 | 16.8 | 20.9

I have found that 3072 is best for reading and 2048 is best for writing, so i just wanted to put 3072 in the read_ahead_kb.

I am trying to change its setting using root explorer but when i am saving it says 'operation failed' also when I am opening the same file again it shows the modified value. The modified value gets lost when I am rebooting the device.

I have given the 777 (full) permission using terminal to the file.

I also tried to create new file using below command but it also gets lost when rebooted.

# echo 3072 > read_ahead_kb

can you please suggest me what should I do to apply the changes permanently?

Thanks.
[Android General] NYLimited:
Yes, 3072 will be better since Android does many more reads than it writes. Good choice.

The read buffer, like the min free values, are always reset to default at boot. You must initialize it on each boot.

I use an app called ROM Toolbox which can do *many* more things and it can also be set to run and do these changes on each boot. There are other smaller apps which will do only the read buffer.

Or, you can create a small script with the echo command (make sure you specify the full path for the destination file) and place the script in the init.d folder. Android will run it for you on each boot. There should be at least one or more scripts there already which Tytung created. You can use them as samples to make your own.

---

* Give a man a fish and you feed him for a day; teach a man to fish and you feed him for a lifetime.
[Android General] Dhruna:
I have created a script and it works, Thank you for your support.

I have just a question, if I choose /data (which is pointing to sd-ext) to check the read/write speed in SD Tools, it is not able to proceed as it is getting write buffer error. Is there any way to test ext4 partition using SD Tools or any other tool ?

Thanks
[Android General] DiamondJohn:
I use "A1 SD Bench" from the market, and have two partitions on my mmc card (32GB). One is an EXT4 data partition taking all but 320MB, which has been partitioned and formatted specifically as a Swap Partition. Not only can it perform tests on the ext4 formatted SD Card, but you can also specify a custom directory (ie where your ext4 partition is mounted)
[Android General] NYLimited:
There are but I would not worry about it. Keep in mind that EXT4 was originally developed for large disk based partitions. Fine tuning the performance of a 2 or 4 GB partition would not be overly significant. Thus file system is quite different from and much more efficient than FAT32. Tytung already applies some fine tuning while mounting the file system.

If you want to read more about it and about the Linux based tools for it there is a lot if info online. You might want to start with some light reading

here

.

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* Give a man a fish and you feed him for a day; teach a man to fish and you feed him for a lifetime.
[Android General] Hottboi505:
A cm mprot2.html
[Android General] higherway:
It's the first time for me to know that such a small card contains so many knowledge .
[Android General] Quis1:
Nice guide, thanks.
[Android General] mirabilos:
Nice post. Too bad the SD Formatter is only available for Windows® and Macintosh (whereas I only have BSD, and Linux at work), and I could use this information for Windows Mobile instead of Android (but then, this is the Android subforum, just I got here via search engine… I’ll try looking more for Windows Mobile 6.1 info).

Where can I find out about…

① what the SD Formatter does, partition layout wise (you said it leaves some “security area”), so I can do that with fdisk on the BSD command line?

② if I can erase an SD card, so its wear levelling assumes all blocks are free, before repartitioning them and “formatting” (creating a FAT filesystem) them?
[Android General] NYLimited:
Have you tried Sun's Virtualbox?

Panasonic would know #1.

Interesting question (#2) but I don't know..

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* You can chose to ignore reality, but you cannot ignore the consequences of ignoring reality.
[Android General] DiamondJohn:
I am running Windows, but have used a GParted boot disk (ie Unix) to make and format partitions on my sd card. I have had unix swap partitions and a large EXT4 partition on a Sandisk Ultra 64GB card. One thing I have learnt is to make sure to leave a substantial unpartitioned area at the front of the card.

http://gparted.org/
[Android General] NYLimited:
Yes, the fat32 partition is usually created first and can act (sort of) like extra space in front. ;)

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* You can chose to ignore reality, but you cannot ignore the consequences of ignoring reality.
[Android General] DiamondJohn:
Yeah, previously I had a phone with no internal SD memory, and had a small fat32 partition (a few GB). However currently I have a phone with built in internal memory, so formatted my external card as a single large ext4 partition, with no "buffer" at the front. I killed 3 cards before I learnt this trick/requirement (no help from sandisk apart from respecting their lifetime warranty)

I have since noted that even on 8GB USB Sandisk thumb drives they provide it with this small un-formatted area, but I couldn't see anywhere they document it, and only found it as a passing comment by a random person on some random forum; and just the single post. Sandisk tech support simply say they do not support partitioning, instead of letting you know this trick, even though they ship it with the card partitioned this way (so obviously they know). End of rant...
[Android General] rronald_25:
Fake kingston 64gb?

Hi,

Sorry if this is not the right forum to ask this.

Recently I bought Kingston micro sdxc class 10 64gb

I perform the h2testw and the results are write 10.4/s, read 17.1/s with no error. (attachment 2)

But I am still not convinced since on the card there is a typo mistake, instead of sdxc 10/64gb, it says sdcx. (attachment 1)

Would be great if somone can at least confirm it from the h2testw result.

Thanx
[Android General] NYLimited:
Wow! I have not personally seen a brand name like Kingston mislabel a card like that! I suppose it is possible but I'd be cautious. You might want to email Kingston and ask them. If real you may have a collector's item. :)

----

You can chose to ignore reality, but you cannot ignore the consequences of ignoring reality.
[Android General] rronald_25:
Thats what I thought, not to mentioned on their website the micro sdxc class 10 has purple stripe in the bottom, so I emailed Kingston and now waiting for their reply.

With Sandisk few years ago, they replied very fast & confirmed mine was fake, thats a good proof to get my money back

Anyway, from the test result, is there something not right, like writing / reading speed to slow for a class 10 card.

Thanx