OT: memory sticks

[Scott]

How can it take over three minutes to delete a couple of (large) files from a memory stick? I thought interacting with solid-state memory would be almost instantaneous.

[Scott]

Sorry, that's wrong.

It's a couple of folders, containing a large number of files.

Still, why should it take more than three minutes?

[Clive Arthur]

Does it save them to your recycle bin? Shift-Delete is quicker in that it doesn't, but can still take a while as all the FAT information needs to be changed and you still only have serial access. Quick format is quick if you can lose everything.

[Windows, btw]

[Scott]

Yes, W10. It doesn't seem to. I don't want to lose the entire contents. Would there be any benefit in using NTFS? I was told not to.

[John Rumm]

Deleting large numbers of files requires a large number of individual disk updates, and memory sticks are usually relatively slow with a large number of small write operations (they are usually optimised for read speed rather than write).

[Pamela]

It sounds like the system is doing more than removing file index entries.

Perhaps you have set something to do a secure delete by writing over all of a file's clusters when it's on removable storage.

[Jethro_uk]

Sometimes it's quicker to format the things ....

[Scott]

It would be, but that is not my intended use.

[Scott]

I think you may have hit on the answer. CCleaner is carrying out secure deletion. I assumed this was for the hard drive only, but it looks as though it may apply to the USB drive also. I'll need to see if there is a way of bypassing CCleaner.

[tim...]

That will depend upon whether your file system is clever enough to read all of the directory file store into memory

delete the files virtually and write the whole lot back in one go

or whether it simply walks through the list and deletes them one at a time

each time it deletes one, it will have to read and write-back the whole directory into a new block

This will be a serious number of random access which are very inefficient

[Pamela]

Bypassing would be an idea as you don't really need to use a cleaner on memory sticks as they don't have a recycle bin and rarely hold temporary files.

[Brian Gaff (Sofa)]

Depends on the speed of the stick and if the socket is USB1 2 or three. Brian

[Brian Gaff (Sofa)]

That does seem a little long what is the size and how was it formatted? Brian

[Brian Gaff (Sofa)]

No don't use ntfs, unless all the machines you want to use it on are capable of reading it. Often some cheap mp3 players cannot read ntfs formats. Brian

[John Rumm]

This is true,

but that is no the reason.

Doing file system overwrites on flash devices is an unreliable way of permanently deleting data at the best of times. The device's wear levelling algorithms can make it impossible to actually overwrite the blocks anyway since attempts to write to specific blocks will likely get redirected to different ones, and all you are really achieving is eating into the devices write cycle budget needlessly.

[Pamela]

My thinking is there are no complete files hidden away after deletion for a cleaner to scrub.

My SSD on XP has no TRIM function. I may be bonkers but I run a hard drive defrag reasoning(?) that reading/writing multiple SSD blocks requires multiple addressing calculations and the fewer of these the lighter the load on the creaky cpu.

Of course the cpu may not be doing this work at all but the habit is psychologically hard to break after years forming the habit! Theory says such defragging is actually deleterious by causing unnecessary wear but the drive will probably get thrown away in a few years and it wasn't desperately expensive, so that's never worried me.

I know I'm doing it wrong, kind of like a driver opening the car sunroof on a hot day to help the air conditioning ... yet it happens.

[Tim Streater]

I suspect you'll find that the SSD is doing the bulk of the work, as it has its own processor.

I don't think I've done defragging for at least 20 years. Even older versions of macOS do that in the background for you.

[Pamela]

Any benefit must be psychological as I've never notice my SSD work faster after a defrag -- although I never noticed a hard drive work noticeably better after a defrag either! Old habits die hard and I dare say I'll be doing a completely unnecessary defrag in a few weeks time. :)

That still counts as defragging. XP also had a similar auto defrag which kicked in periodically although many users disabled it and ran their defrags on demand.

[The Natural Philosopher]

No OS apart from DOS/windows running FAT ever needed de fragging anyway. And since there is no time penalty on seeks, its is a pointless exercise on an SSD, made even MORE pointless by the fact that what appears to be adjacent sectors on the SSD may be in reality anywhere on the device block map, having been remapped as part of the wear levelling process. In short there is a sophisticated processor and operating system inside the SSD dedicated to sorting out all the shit, that functions best, like an erect penis, if you don't f*ck with it...

The golden rule with an SSD is 'DO NOT WRITE TO ME IF POSSIBLE' . Nothing you can do will make it perform better and every write takes you nearer end of life.

It is not a disk, it is a computer whose non volatile memory is accessed via a SATA interface. Running its own operating system dedicated to spreading the writes and erases across blocks of RAM as evenly as possible. And the addresses it accesses bear zero relationship to the addresses requested and presented on the SATA interface.

[Vir Campestris]

I've never been convinced about that. If I fill a disc with 1000 files, then delete every other one, how is the free space not going to be fragmented?

With you there all the way.

Andy