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Hello community,
I bought a OCZ RevoDrive 3 X2 (240GB) some years ago, and didn't use it until now, because booting from it was close to impossible. Meanwhile I am using a SATA SSD (Corsair Force 3) and wondered if I could put my /home onto the RevoDrive. Sadly it seems rather complicated to set up, even when not booting from the RevoDrive. I failed to set it up as a FakeRaid, because when I switch SATA mode from ACPI to RAID, neither Linux nor Windows are able to boot. So I used mdadm to create a software RAID 0 like so:
# mdadm --create --verbose --level=0 --metadata=1.2 --chunk=64 --raid-devices=2 /dev/md0 /dev/sdb1 /dev/sdc1
# mdadm --detail --scan >> /etc/mdadm.conf
# mdadm --assemble --scan
# mkfs.ext4 -L revodrive -b 4096 -E stride=16,stripe-width=32 /dev/md0I thought that would do the trick, and I mounted and tested the RAID. But unfortunately the perfmance is worse that on my SATA SSD:
# bonnie++ -u root
[...]
Version 1.97 ------Sequential Output------ --Sequential Input- --Random-
Concurrency 1 -Per Chr- --Block-- -Rewrite- -Per Chr- --Block-- --Seeks--
Machine Size K/sec %CP K/sec %CP K/sec %CP K/sec %CP K/sec %CP /sec %CP
home 32040M 763 99 852238 82 222109 27 5152 99 390778 17 5614 119
Latency 23508us 162ms 394ms 4541us 2696us 4403us
Version 1.97 ------Sequential Create------ --------Random Create--------
home -Create-- --Read--- -Delete-- -Create-- --Read--- -Delete--
files /sec %CP /sec %CP /sec %CP /sec %CP /sec %CP /sec %CP
16 808 0 +++++ +++ +++++ +++ +++++ +++ +++++ +++ +++++ +++
Latency 9931us 564us 497us 161us 9us 245us
1.97,1.97,home,1,1398722363,32040M,,763,99,852238,82,222109,27,5152,99,390778,17,5614,119,16,,,,,808,0,+++++,+++,+++++,+++,+++++,+++,+++++,+++,+++++,+++,23508us,162ms,394ms,4541us,2696us,4403us,9931us,564us,497us,161us,9us,245usCopared to the SATA SSD:
# bonnie++ -u root
[...]
Version 1.97 ------Sequential Output------ --Sequential Input- --Random-
Concurrency 1 -Per Chr- --Block-- -Rewrite- -Per Chr- --Block-- --Seeks--
Machine Size K/sec %CP K/sec %CP K/sec %CP K/sec %CP K/sec %CP /sec %CP
home 32040M 1058 99 506126 57 217990 24 +++++ +++ 531602 23 +++++ +++
Latency 16826us 82560us 532ms 4408us 1621us 4536us
Version 1.97 ------Sequential Create------ --------Random Create--------
home -Create-- --Read--- -Delete-- -Create-- --Read--- -Delete--
files /sec %CP /sec %CP /sec %CP /sec %CP /sec %CP /sec %CP
16 1382 1 +++++ +++ +++++ +++ +++++ +++ +++++ +++ +++++ +++
Latency 151us 561us 684us 163us 9us 216us
1.97,1.97,home,1,1398726407,32040M,,1058,99,506126,57,217990,24,+++++,+++,531602,23,+++++,+++,16,,,,,1382,1,+++++,+++,+++++,+++,+++++,+++,+++++,+++,+++++,+++,16826us,82560us,532ms,4408us,1621us,4536us,151us,561us,684us,163us,9us,216usSo I was wondering if my mdadm setup is broken, or sofware raids just don't work as I expected? Would it be better to set SATA mode to RAID and freshly set up both, Windows and Linux?
Thank you!
Last edited by carlk (2014-05-08 10:51:13)
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Just curious.. any specific reason for specifying the chunk and stide sizes? Have you tried without? I would imagine that the defaults would be acceptable...
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Thanks for the hint, I took those values from someone else with a RevoDrive. Clearly he didn't know what he was doing (just like me). It sure looks better now with a chunk size of 512 (default):
# bonnie++ -u root
[...]
Version 1.97 ------Sequential Output------ --Sequential Input- --Random-
Concurrency 1 -Per Chr- --Block-- -Rewrite- -Per Chr- --Block-- --Seeks--
Machine Size K/sec %CP K/sec %CP K/sec %CP K/sec %CP K/sec %CP /sec %CP
home 32040M 1093 99 855825 78 341657 33 +++++ +++ 696280 24 5811 92
Latency 16538us 161ms 210ms 3907us 4270us 4653us
Version 1.97 ------Sequential Create------ --------Random Create--------
home -Create-- --Read--- -Delete-- -Create-- --Read--- -Delete--
files /sec %CP /sec %CP /sec %CP /sec %CP /sec %CP /sec %CP
16 2305 2 +++++ +++ +++++ +++ +++++ +++ +++++ +++ +++++ +++
Latency 10532us 571us 449us 175us 12us 186us
1.97,1.97,home,1,1399544652,32040M,,1093,99,855825,78,341657,33,+++++,+++,696280,24,5811,92,16,,,,,2305,2,+++++,+++,+++++,+++,+++++,+++,+++++,+++,+++++,+++,16538us,161ms,210ms,3907us,4270us,4653us,10532us,571us,449us,175us,12us,186usBut after all I guess I'm going to sell the drive on ebay. OCZ did a pretty good job on messing with Linux folks with this drive, and I'm kind of tired of working around their issues...
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I got one for Christmas about two years ago when they first came out, the thing was like 128 or 256 GB and was about $450. I was elated when I saw it, but that quickly turned to disappointment when I saw that I couldn't install both Windows and Linux on the same device since my BIOS and Windows saw it as one device, but Linux saw it as two SSDs. There wasn't even support for it in Arch at this time I had to seek out a kernel module that some Canadian guy built, which again only gave two SSDs since OCZ decided to make everything proprietary. I contacted them about this and they pretty much just gave me a big "FU we don't care".
After having 3 of their SSDs fail on me (one was the replacement for the failed drive!) and then this fiasco, I will never buy another OCZ SSD again.
I just read that SATA-Express SSDs will start production soon and PCI-E SSDs that look like our typical 2.5" SATA SSDs will use 2 SATA ports and another special PCI-E port on the motherboard to achieve the crazy speeds of PCI plug-in SSDs without the proprietary controllers and drivers!
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