We currently/still write to tape for off-site backups (avg size is 80 GB per day) and the robot is misbehaving as of late. I'm setting up an NFS share on Ubuntu Server 14 (16 when it releases) to receive off-site backups from a Solaris 5.9 server, then I'll write the backup to a USB flash drive. Testing so far has been impressive. The OS drive on US is SSD and the mobo has USB 3 ports. I created a 1 GB and 10 GB file in the NFS folder with dd and copied to the flash drive. Write speeds to the flash drive were over 200 MB/s. However, the 10 GB file failed at 4 GB because of the FAT32 file system on the flash drive.

I don't yet know the format of the backup. I'm assuming it's using tar to write to tape; if so, I could still use tar and just write out to a file. I digress.

I deleted and re-created the partition on the USB drive, then formatted the new partition with NTFS. Write speeds went down to around 70 MB/s. I then formatted the flash drive as ext2. Write speeds went down further to around 45 MB/s. Is there a faster file system type or optimal disk geometry (block size, cluster size, inode, superblock count, etc.) which would get me back to 200+MB/s, or at least over 100 MB/s?

UPDATE: User (@Brian) suggested exFAT. exFAT had the faster write speeds of the different FSs I tried.

I formatted the flash drive as follows:

mkfs.ext4 -b -4096 -L 'PNY128GB' -N 4096 -v /dev/sdb1 yielded 96 MB/s

mkfs.exfat -n 'PNY128GB' yielded 106 MB/s

  • 1
    Did you try exfat? – user508889 Apr 14 '16 at 2:04
  • That's my next "try". I hate stabbing in the dark with this because writing the inode tables take a long time. – user38537 Apr 14 '16 at 2:06
  • I can understand that, and I can't answer your question. However, I think a large block size with exfat will give you the results you would like to see. Please update as you can. – user508889 Apr 14 '16 at 2:14
  • @Brian, make your answer exFAT and I'll accept it as the answer. It edged out ext4 by 10 MB/s. – user38537 Apr 14 '16 at 4:08
  • Glad it worked out! I'll let someone else come along and answer it with more detailed information than I have. One thing for you to consider though, the reliability of the filesystem versus speed. Exfat had flash in mind when it was created, so performance gains over a journaled filesystem, but it's not the perfect filesystem. – user508889 Apr 14 '16 at 11:38

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