You can make a difference in the Apple Support Community!

When you sign up with your Apple Account, you can provide valuable feedback to other community members by upvoting helpful replies and User Tips.

Looks like no one’s replied in a while. To start the conversation again, simply ask a new question.

To connect an external hdd to an iPad Pro 2020 11”

I Tried to connect an external hdd (maxtor m3 portable 1tb usb 3.0) via external usb-c adapter (baseus 6 in 1 usb-c hub) to my iPad Pro 2020 11” , but the iPad doesn’t find it. I don’t have problem with sdcard, microsdcard, usb pen drive. When I inserted the hdd, iPad was in charge, via ext power supply. I saw on an you tube tutorial, using the same usb c hub, that all worked properly. Does someone know in wich way can I solve this problem? Thanks in advance.

Posted on Jun 24, 2020 6:54 AM

Reply
Question marked as Top-ranking reply

Posted on Jun 24, 2020 6:59 AM

Your HDD must only have a single data partition - and be formatted as FAT32, exFAT or APFS. Multiple data partitions and Microsoft proprietary formats (such as NTFS) are not support by iPadOS.


You must also ensure that the HDD has an adequate source of power other than the iPad. If the HDD does not have an integral power supply, you must use a powered USB hub.


The iPad alone cannot supply sufficient power to high-power USB devices.

3 replies
Question marked as Top-ranking reply

Jun 24, 2020 6:59 AM in response to lino144

Your HDD must only have a single data partition - and be formatted as FAT32, exFAT or APFS. Multiple data partitions and Microsoft proprietary formats (such as NTFS) are not support by iPadOS.


You must also ensure that the HDD has an adequate source of power other than the iPad. If the HDD does not have an integral power supply, you must use a powered USB hub.


The iPad alone cannot supply sufficient power to high-power USB devices.

Jul 7, 2020 7:32 AM in response to LotusPilot

I formatted the HDD in ex-FAT and now the IPAD sees it. If I disconnect it from the IPAD and reconnect it again, the IPAD no longer recognizes it. I have to put it in a PC, restore the unit, due to errors detected on the disk, disconnect it from the PC and, at this point, I can reconnect it to the IPAD that recognizes it. The error is systematic. Is there a procedure to properly disconnect the HDD from the IPAD?

Jul 7, 2020 8:25 AM in response to lino144

The technical cause is most likely due to write-caching - this being a feature of high volume HDD and SSD storage devices.


For most desktop computers, it is possible to configure an externally attached storage device either for performance (i.e., uses write-caching) or for Quick Removal. This determines how and when information is “written” to the storage device.


When configured for Quick Removal, information from the host computer is written immediately to the storage medium. This has the advantage that you may disconnect the storage device from the host computer, without risk of corrupting the file-system, at any time that data is not being actively transmitted to the storage device. Whilst being a completely valid and useful method of managing data storage, for reasons beyond the immediate scope of this description, this method is less efficient and slower.


Alternatively, when write-caching is enabled, information from the host computer is “cached” in separate (high performance) volatile storage within the storage device - and when sufficient information has been received, a “block” of data is written in a single write-cycle. Whilst being faster and more efficient, this method comes with the penalty of the host computer having to notify the storage device of a impending device-disconnection before it is disconnected. This warning ensures that the storage device will flush any pending data from its volatile cache-memory to non-volatile storage - and in so doing sets a “clean switch” on the flash filesystem and signals to the computer that it is safe to disconnect.


A drive configured for write-caching, upon connection to a host computer, is checked for the “clean switch”; if present, the storage device is “mounted” and made available to the operating system. By contrast, if the “clean switch” is not detected (this will occur if the storage device was disconnected prior to being notified of a “dismount”), the filesystem must be assumed to be potentially corrupt; pending data within the write-cache may not have been written to the drive.


So, the relevance of this to iPad is simple; iPad does not fully support devices that are implement write-caching. iPadOS lacks the ability to inform the storage device of imminent disconnection of the storage device from the USB bus. iPad also lacks capability to detect and scan/repair corrupt storage devices.


In summary, now that you [hopefully] understand both the cause and effect, you will now understand that you can only reliably use USB-connected storage devices that can be configured for Quick Disconnect operation - this having major significance to non-corruption of the filesystem and reduced data throughput.


Unfortunately, with iPadOS lacking a native mechanism to reliably dismount a running filesystem, the only available mechanism to safely dismount is to shut-down the iPad before physically disconnecting:

Settings > General > Shut Down


I hope this technical explanation is helpful in fully explaining the behaviour that you observe.

To connect an external hdd to an iPad Pro 2020 11”

Welcome to Apple Support Community
A forum where Apple customers help each other with their products. Get started with your Apple Account.