9.0 crash, ssd or filesystem problem?

[Gary Aitken]

On 11/16/12 12:10, Warren Block wrote:

>>>>>> ~$ gpart show ada0
>>>>>> =>       34  250069613  ada0  GPT  (119G)
>>>>>>         34        128     1  freebsd-boot  (64k)
>>>>>>        162   41943040     2  freebsd-ufs  (20G)      /
>>>>>>   41943202    1048576     3  freebsd-swap  (512M)    swap
>>>>>>   42991778    8388608     4  freebsd-ufs  (4.0G)     /var
>>>>>>   51380386    4194304     5  freebsd-ufs  (2.0G)     /tmp
>>>>>>   55574690  192216088     6  freebsd-ufs  (91G)      /usr
>>>>>>  247790778    2278869        - free -  (1.1G)
>>>>>
>>>>> It would not cause this problem, but those partitions are not aligned.
>>>>> That would only affect speed, not reliability.
>>>>
>>>> geezes, it's not even on a 4K boundary from the get-go;
>>>> not sure how that happened.
>>>> let-alone the 1M boundary I just learned about.
>>>
>>> That's a normal install.  It's fine for 512-byte devices.
>>> I have other suggestions too, but let's save that until the problem is fixed.
>>
>> aaahhh.  Vague recollections of getting this to boot up first time around.

After upgrading the mobo bios I re-partitioned and so far so good
although ports are messed up and I'll have to rebuild them.
Did not implement the suggestions below as I needed to get back up and 
figured it would take me a while to get it right.  Will do that on the 
new disk.

>> How about suggestions anyway, as I'm going to build an sata disk and move
>> things to that as part of the process to see what's wrong.  May as well get
>> it right-ish the first time; then repartition the SSD.
> 
> Okay.  The disk setup article shows alignment and using GPT labels, so
> I'll skip those.
> 
> Additional SSD suggestions: when creating partitions, leave out the swap
> partition.  If you have lots of memory, leave out the /tmp partition. Add
> that extra space to the /usr partition.
> 
> Format the UFS filesystems with -Ut, for soft updates and TRIM support.
> (Make sure your SSD supports TRIM, almost all do.)  (I don't use soft
> updates journaling.)
> 
> Use dd(1) to make a zero-filled file on /usr somewhere, say /usr/swap.
> Make it the size you want swap to be, and do not make it a sparse file.
> Tell the system to use the swapfile in /etc/rc.conf:
> 
>    swapfile="/usr/swap"
> 
> Use tmpfs for /tmp in /etc/fstab:
> 
>    tmpfs        /tmp    tmpfs    rw,mode=01777    0    0
> 
> It's possible to limit the size, but not necessary.  This /tmp will be
> cleared on reboot.

Not necessary because it is constrained by the swap file size?

> Now: why?
> 
> Using a swapfile through the filesystem gives three advantages:
> 
> 1. Disk space is not tied up in an unused swap partition.
> 2. Swap can be resized without repartitioning.
> 3. Swap goes through the filesystem, using TRIM, helping the SSD
>     maintain performance.
> 
> /tmp as tmpfs is auto-sizing, efficient, and self-clearing on reboot.
> It doesn't tie up disk space in a mostly-unused partition.
> 
> I use tmpfs for /usr/obj also.  It doesn't improve speed, but reduces
> writes to SSD and is also self-clearing.

Thanks!