Questions about erasing an ssd to restore performance under FreeBSD

[Steven Hartland]

There seems to be loads of info about this but nothing concrete so
I'm hoping someone here can answer some questions:-

1. Does newfs -E work on all controllers or only in combination
with ahci ada driver? In our case the drivers are off an LSI controller
using the mpt driver

mpt0: <LSILogic SAS/SATA Adapter> port 0xfc00-0xfcff mem 0xdf2ec000-0xdf2effff,0xdf2f0000-0xdf2fffff irq 16 at device 0.0 on pci2
mpt0: [ITHREAD]
mpt0: MPI Version=1.5.18.0
mpt0: Capabilities: ( RAID-0 RAID-1E RAID-1 )
mpt0: 0 Active Volumes (2 Max)
mpt0: 0 Hidden Drive Members (14 Max)

2. If newfs -E doesn't work, which I suspect is the case, is using
something like partedmagic boot cd and the secure erase app in that
still an option or is that again thwarted by the LSI controller?

3. If neither #1 or #2 work is there an alternative which will
without taking the drive out of the machine putting it in something
which supports ada and running one of the above on that machine?

My current testing seems to indicate neither #1 or #2 work in this
case as write performance on Corsair SSD is still terrible after
both. If #1 does require ata then it would be good to note this in
the man page for newfs which currently indicates it will just work.

da1 at mpt0 bus 0 scbus0 target 1 lun 0
da1: <ATA Corsair CSSD-F60 2.0> Fixed Direct Access SCSI-5 device
da1: 300.000MB/s transfers
da1: Command Queueing enabled
da1: 57241MB (117231408 512 byte sectors: 255H 63S/T 7297C)

By terrible I mean under 20MB/s sequential write speed where as a
new drive in a similar machine is showing closer to 200MB/s write

oldssd# dd if=/data/test of=/ssd/test bs=1m
1000+0 records in
1000+0 records out
1048576000 bytes transferred in 60.430616 secs (17351734 bytes/sec)

newssd# dd if=/data/test of=/ssd/test bs=1m 
1000+0 records in
1000+0 records out
1048576000 bytes transferred in 0.555287 secs (1888349211 bytes/sec)

In both tests /data/test was just created from /dev/random onto
a standard HD but is still in ARC so read speed is very high, hence
not the limiting factor.

    Regards
    Steve


================================================
This e.mail is private and confidential between Multiplay (UK) Ltd. and the person or entity to whom it is addressed. In the event of misdirection, the recipient is prohibited from using, copying, printing or otherwise disseminating it or any information contained in it. 

In the event of misdirection, illegible or incomplete transmission please telephone +44 845 868 1337
or return the E.mail to postmaster at multiplay.co.uk.