Disk overload?! (SOLVED!)

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Has anyone found a solution? It's so annoying that I'm considering finding an alternative to uTorrent. It happens all the time when a torrent with several files is added. uTorrent becomes unresponsive, and overloads the disk for a while.

Solution; the disk partition which uTorrent is downloading files to needs to be formatted as NTFS. A FAT32 partition may be converted to NTFS without loss of data. An exFAT partition needs to be formatted. Also, make sure that "Pre-allocate all files" is disabled, and that "diskio.sparse_files" in advanced settings is set to true.

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I think the issue could be solved by downloading the files one by one - instead of all at once, preferably in chronological order. However, it's a hassle to do it manually.

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The storage disk has exFAT file system, while the OS is running on NTFS (obviously). Could that be causing an issue?

System specifications; Intel C236 chipset, Intel Xeon E3 3GHz, ECC DDR4 16GB, SanDisk X300 256GB, WD Re 4TB, Windows 10 Professional, 64-bit

Internet connection; fiber-optic, 100/100 Mbit

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File size seems to be an issue as well. I just added a 30 GB file, and observed both uTorrent and the computer performance in task manager. It started downloading at high speed, and suddently it just dropped to zero. Task manager showed that the HDD was being overloaded, while something was constantly writing at around 100 MB/s. It stayed this way for a couple of minutes or so, before it dropped too, and the torrent started downloading at high speed again. From there on, the HDD was writing around 12 MB/s - the same speed as uTorrent was downloading the file. So my question is, what is uTorrent writing to the disk when a download is initiated? I repeat, the HDD was being overloaded at around 100 MB/s for a couple of minutes or so - while there was nothing being downloaded through uTorrent...

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Quote

• Pre-allocate all files tells µTorrent to create and fully allocate every file you select to download immediately after starting the torrent job. Note that this option does not have an impact on hard drive fragmentation (advantageous or otherwise), as µTorrent already allocates each file upon writing to disk even without this option.

Maybe there's an issue with the allocation of large- and/or multiple files?

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There's no issue when downloading large torrents to the SSD. However, all hell breaks loose when uTorrent is moving the completed download to the HDD. I also changed uTorrent's priority level to low in task manager/details, but it seemed to be ignored.

As far as I can see, the issue is caused by allocation. It seems as it's pre-allocating files despite that the option is disabled. Why does it have to do this? The issue may probably be avoided by checking/monitoring available disk space before the download begins, and then allocating disk space in realtime.

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It's definitely an issue with allocation of files, and it's not unique to uTorrent. I've the same issue with qBittorrent, and Deluge - with the full allocation setting enabled. HOWEVER, there's no issue with Deluge when the compact allocation setting is used instead! Just a tip for everyone else who's struggling with the disk overload issue.

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I started experiencing some weird issues with Deluge, and decided to investigate the uTorrent issue further. I've discovered that the true issue is the file system. No more disk overload after changing from exFAT to NTFS! Some people say that disk overload is more common with external drives due to limited transfer speeds, but I think the reason is that many - if not all disks comes with FAT32. FAT32 may be changed to NTFS without loss of data. A drive with exFAT needs to be formatted.

Quote

 

diskio.sparse_files: Enabling this option causes µTorrent to allocate only the data that it writes, but will inform the filesystem of the file's size (so that it can attempt to reserve enough contiguous space on the hard drive without having to physically zero all of the space out for the file). Even though space is reserved for the file, no space will be taken for the unwritten parts of the file. Enabling this option may potentially lead to increased disk fragmentation in rare cases where the drive does not have enough free space available to honor the space reservation for sparse files. Here are some things to take note of when using this option: 

- Sparse files work only on partitions that are formatted as NTFS.
- Hash checking sparse files tends to be quicker than hash checking pre-allocated files, as µTorrent won't have to hash zeroed-out pre-allocated data. 
- On Windows Vista, sparse files can cause µTorrent to run into a file system limitation. 
- If you are using a non-administrator account with a disk quota, sparse files won't work, and the file will still get fully allocated. This is a limitation with Windows that µTorrent can't do anything about. 
- This option cannot be used in conjunction with pre-allocate all files. If both options are enabled simultaneously, pre-allocation will take precedence. 
- When used in conjunction with bt.compact_allocation, µTorrent will reserve space for each file in the filesystem, but it will continue to use compact writes.

I also have to say that I'm very disappointed that there's no official response in this forum. The disk overload issue has been frustrating for a long time - and the solution was this simple. 

[eddlang]

Nice find. Such an important information, buried in help. I think this thread should be sticky-ed. I've seen many people creating threads about disk overload and a lot of them remained unsolved.

Basically:

1. Make sure "diskio.sparse_files" is set to "true" in advanced settings, although it should be on by default.

2. Disk partitions should be formatted as NTFS.

3. "Pre-allocate all files" should be disabled, obviously.

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Correct. Now, if I could only find a solution to the damn memory issue, I would be happy;