I have Ubuntu 15.10 setup on a ssd partition on my rMBP. The root partition is zfs.
When I'm natively booted into ubuntu, I'm getting very slow write speeds:
However, when I'm booted into El Capitan, and then run ubuntu from virtualbox accessing the exact same partition in raw mode, I get much faster disk access.
At first I thought this was either an issue with an older kernel or zfs, so I made sure that I was running a current kernel (kernel 4.4.0) as well as a current zfs build (v0.6.5.4-1~wily from a current zfs ppa). Updating that software made no difference.
But booting in a virtual machine did make a difference.
So I'm assuming that this isn't a zfs issue then, but instead an issue with how linux is accessing the SSD. Any ideas?
Is anybody else having slow disk access on one of these machines? It is very noticeable when trying to update any software... especially when unpacking lots of small files.
When I'm natively booted into ubuntu, I'm getting very slow write speeds:
Code:
dd if=/dev/zero of=tempfile bs=1M count=1024 conv=fdatasync,notrunc
1024+0 records in
1024+0 records out
1073741824 bytes (1.1 GB) copied, 5.74565 s, 187 MB/sHowever, when I'm booted into El Capitan, and then run ubuntu from virtualbox accessing the exact same partition in raw mode, I get much faster disk access.
Code:
dd if=/dev/zero of=tempfile bs=1M count=1024 conv=fdatasync,notrunc
1024+0 records in
1024+0 records out
1073741824 bytes (1.1 GB) copied, 0.521114 s, 2.1 GB/sAt first I thought this was either an issue with an older kernel or zfs, so I made sure that I was running a current kernel (kernel 4.4.0) as well as a current zfs build (v0.6.5.4-1~wily from a current zfs ppa). Updating that software made no difference.
But booting in a virtual machine did make a difference.
So I'm assuming that this isn't a zfs issue then, but instead an issue with how linux is accessing the SSD. Any ideas?
Is anybody else having slow disk access on one of these machines? It is very noticeable when trying to update any software... especially when unpacking lots of small files.