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My MySQL program is on /. If I move my databases to a partition (a separate hard-disk drive) mounted on /tee, then reads and writes (MySQL queries) take an exceedingly long time: many times more than the same reads and writes when the databases are on /. What can I do to improve this? Any advice would be most welcome.

Note that reading and writing /tee seems to be pretty quick other than in MySQL: for example,

/tee$ for i in {1..100}; do find >> find; done

took 18 seconds. (find |wc -l yields 15010.)

Note also that df -T yields:

Filesystem                      Type      1K-blocks      Used  Available Use% Mounted on
/dev/mapper/HCG--Linux--01-root ext4      124241852 117926300          0 100% /
none                            tmpfs             4         0          4   0% /sys/fs/cgroup
udev                            devtmpfs    8199904         4    8199900   1% /dev
tmpfs                           tmpfs       1641948       356    1641592   1% /run
none                            tmpfs          5120         0       5120   0% /run/lock
none                            tmpfs       8209724         0    8209724   0% /run/shm
none                            tmpfs        102400         0     102400   0% /run/user
/dev/sda1                       fuseblk  2930232316  46281132 2883951184   2% /tee
/dev/sdb1                       ext2         233191    160033      60717  73% /boot

Obviously, I want this question to be useful to future users with a similar problem, so a general answer addressing many users' concerns would be ideal. Hence, I didn't supply many details. But I don't know whether what I have provided is sufficient. I'll be very glad to supply any details that I need to provide to strike the correct balance so this is both answerable and broadly applicable, if someone comments on this question advising me what those details are.

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I had a problem with speed when I tried to use a second hard disk, I found, after a lot of hunting, scanning and sweat, that there were bad sectors on the second HDD, a new HDD sped things up considerably.

  • Thanks. That might be the issue here, but reading and writing to /tee seem to be pretty quick other than in MySQL. I'm editing the question to clarify. – msh210 Jul 17 '13 at 16:54
  • Is the second partition on the same or a different HDD? If on a second HDD is it internal or external and how is it connected? May be, more importantly, what format are / and /tee formatted to? – SimplySimon Jul 17 '13 at 17:14
  • It's a different HDD. I don't know whether it's internal or external, nor how it's connected: I ssh in and have never seen this machine. I'll add the output of df -T to the question. – msh210 Jul 17 '13 at 17:17
  • OK, I have been searching around for the past 20 minutes trying to find an answer to this, and I can not find one, I can't help wondering if it is because MYSQL is on a different partition type, fuseblk/NTSF whilst the server is on an ext4 partition. I wouldn't have thought it would have made any difference, but if not that it could be to the age/speed/cache/reliability of the sda1 HDD – SimplySimon Jul 17 '13 at 17:42

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