Some months ago I bought a Samsung Evo + microSD card as a boot device for an RPI3B (under FreeBSD-current). Initially it seemed as fast or faster than Sandisk Extreme cards used previously.
Lately, it's become extremely slow. At first I thought it might be FreeBSD's fault, but now I'm starting to wonder if the card is the culprit.
Has anybody observed similar behavior under Raspbian?
Thanks for reading,
bob prohaska
Hello bob!
Saturday November 02 2019 23:29, you wrote to All:
If, the Samsung EVO is a SSD are you running fstrim -av once a day? fstrim does a process called garbage collection that resets a unused sectors that did hold valid data/programs but is no longer used and tells the SSD that these are free to use. Over time regardles of the SSD size it will show all the signs of being full despite *nix thinking it has loads of free space to the point that the system will just lock up.
The Samsungs have a fast internal controller that does this process while the system is in use but many other brands controller needs the system being totally idle to complete this process and this can take 8 hours or more - Crucial is but one brand that comes to mind from bitter experience :(
If it is a SD card then one possible is fragmentation and yes a drive can become over time so.
As there is no clean up tools for this as technically you do not get it, it does happen where sectors of a file or more importantly large executables can be spread all over a drive and a slow down can be noticed some times HOWEVER it is very slight as against a DASD.
The only fix for this is to mount the original SD and a freshly formatted one and copy over all content on a file by file basis. {For a SD this should not be appearing but it could indicate a reduction in free sectors that have not been as used as others that have had a high usage and are wearing out. One of the drawbacks of using SD cards.
Vince
Hello The!
Sunday November 03 2019 18:20, you wrote to me:
No he did NOT, he said Samsung EVO + SD card that implies two devices!
Vince
I suspect you might be swapping to the card. One of the easiest ways to see when that happens if you are using the desktop is to install the CPU monitor widget, and configure it user=green, system=red, nice=blue and IO=orange. If you notice lots of orange, its swapping.
If that is the case, you need something better than an SD card, at minimum a USB 3.1 stick, but an SSD is much better. Alternately a Pi4 with 4GB will eliminate most swapping.
---druck
-- "I am inclined to tell the truth and dislike people who lie consistently. This makes me unfit for the company of people of a Left persuasion, and all women"
I hate to contradict, but there *is* a Samsung microSD card that Samsung labels as the "EVO+" or the "EVO Plus" - the reason they use both notations is, I suspect, known only to competing gangs of Samsung marketeers. A quick search showed Samsung uses both labels.
-- Martin | martin at Gregorie | gregorie dot org
Maybe OTT, but...
I bought four 64GB Samsung Evo+ on eBay (stupid, I know) and they were ALL fakes, but their packaging was convincingly genuine. They were extremely slow putting an OS on, and had announced themselves as 67GB. Using fsprobe (Linux, but based upon Windows h2testw) they were all below 16GB - their controllers had been tampered with. Doing a Benchmark using an SDcard reader via UbuntuMATE gave most revealing graphs which were far from normal. The seller was confident that I was bluffing, and refused to give a refund unless the cards were returned. A challenge via eBay did nothing, but one via PayPal went uncontested, so I got my money back. An unfavourable review on eBay, repeated several times, never got published. Caveat emptor...
-- Mark J From RISCOS 5.25 on a BeagleBoard-xM and Raspberry Pi2B - and Linux on a PandaBoard ES and Raspberry Pi3B
No reason so far to suspect a counterfeit.
Initial performance on my card (128 GB) was quite good. Things didn't get slow for several months. At that time I accidentally allowed the card to reach some 97% of capacity, which I'm told is bad for them. However it didn't stop working and I cleaned house, getting it back to about 77 % of capacity. At roughly the same time I noticed a slowdown when storage activity was high, for example when extracting tar files. The sluggish performance has persisted for over a month, but the card hasn't failed in any decisive way.
Since this is on FreeBSD-current, with which people are constantly tinkering, I first suspected an OS problem. No supporting evidence for that proposition has emerged, so I'm casting a wider net.
Thanks for reading,
bob prohaska
Hello Martin!
Sunday November 03 2019 23:28, you wrote to me:
I stand corrected, sorry but the trough was the '+'.
Vince
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