This might be more of a hardware question than anything, but I noticed
the drive is fairly fast on initial writes, but dramatically slows down
over time with a consistent write.
At bootup time, I can blast out a file (UFS2 mount)
# dd if=/dev/zero of=/mnt/tmp/junk.bin.`date "+%s"` bs=1m
status=progress count=4000
3735027712 bytes (3735 MB, 3562 MiB) transferred 7.014s, 533 MB/s
#
nice and fast. But subsequent writes really start to tank.
# dd if=/dev/zero of=/mnt/tmp/junk.bin.`date "+%s"` bs=1m
status=progress count=4000
4128243712 bytes (4128 MB, 3937 MiB) transferred 46.048s, 90 MB/s
# dd if=/dev/zero of=/mnt/tmp/junk.bin.`date "+%s"` bs=1m
status=progress count=4000
3992977408 bytes (3993 MB, 3808 MiB) transferred 31.016s, 129 MB/s
If I wait for 2min, it seems to be back to normal
# sleep 120 ; dd if=/dev/zero of=/mnt/tmp/junk.bin.`date "+%s"` bs=1m
status=progress count=4000
4137680896 bytes (4138 MB, 3946 MiB) transferred 9.025s, 458 MB/s
Is there something going on behind the scenes limiting the amount of
sustained writes these drives can handle ? Is it just a limitation of
the SSD ? I didnt notice such issues on some consumer Samsungs. The
problem initially showed up for me when I was doing a series of zfs send
| zfs recv on the same pool (so a lot of reads and writes at the same
time) and I would get a bunch of errors on the WD disks. Replacing them
with Samsungs avoids the errors.
=== START OF INFORMATION SECTION ===
Device Model: WD Blue SA510 2.5 1000GB
Serial Number: 240406800001
LU WWN Device Id: 5 001b44 8b334e00b
Firmware Version: 52046100
User Capacity: 1,000,204,886,016 bytes [1.00 TB]
Sector Size: 512 bytes logical/physical
Rotation Rate: Solid State Device
Form Factor: 2.5 inches
TRIM Command: Available, deterministic
Device is: Not in smartctl database 7.3/5528
ATA Version is: ACS-4, ACS-2 T13/2015-D revision 3
SATA Version is: SATA 3.2, 6.0 Gb/s (current: 6.0 Gb/s)
Local Time is: Thu Mar 14 14:41:58 2024 EDT
SMART support is: Available - device has SMART capability.
SMART support is: Enabled
# camcontrol iden ada1
pass1: <WD Blue SA510 2.5 1000GB 52046100> ACS-4 ATA SATA 3.x device
pass1: 600.000MB/s transfers (SATA 3.x, UDMA6, PIO 512bytes)
protocol ACS-4 ATA SATA 3.x
device model WD Blue SA510 2.5 1000GB
firmware revision 52046100
serial number 240406800001
WWN 5001b448b334e00b
additional product id
cylinders 16383
heads 16
sectors/track 63
sector size logical 512, physical 512, offset 0
LBA supported 268435455 sectors
LBA48 supported 1953525168 sectors
PIO supported PIO4
DMA supported WDMA2 UDMA6
media RPM non-rotating
Zoned-Device Commands no
Feature Support Enabled Value Vendor
read ahead yes yes
write cache yes yes
flush cache yes yes
Native Command Queuing (NCQ) yes 32 tags
NCQ Priority Information no
NCQ Non-Data Command no
NCQ Streaming no
Receive & Send FPDMA Queued no
NCQ Autosense no
SMART yes yes
security yes no
power management yes yes
microcode download yes yes
advanced power management yes no 0/0x00
automatic acoustic management no no
media status notification no no
power-up in Standby no no
write-read-verify no no
unload no no
general purpose logging yes yes
free-fall no no
sense data reporting no no
extended power conditions no no
device statistics notification no no
Data Set Management (DSM/TRIM) yes
DSM - max 512byte blocks yes 8
DSM - deterministic read yes any value
Trusted Computing no
encrypts all user data no
Sanitize yes block,
Sanitize - commands allowed yes
Sanitize - antifreeze lock yes
Host Protected Area (HPA) no
Accessible Max Address Config yes no 1953525168/1953525168
RELENG_14 from today
