I am a big fan of having more than one RAID system on my servers
and workstations. Some may consider it overkill, but I always separate
my OS and my data systems, the OS systems being of course much smaller
than the data systems. Some of my systems use RAID1 instead of RAID6,
since even SSDs are fairly inexpensive in modest sizes. Thus, all the
servers employ RAID1 for booting. My workstations generally require
much larger root partitions, so rather than spend a lot on large SSD
systems, I buy multiple, less expensive, smaller SSDs and create a RAID6
boot system.
I have been using ASUS motherboards with AMD processors for years
and have been very pleased with the results. All of my RAID-served
systems employ 8 core AMD FX processors. My servers are not heavily
loaded, so I haven't bothered to go with server class motherboards or
processors. There is no question that internet providers or large
corporations need large server-class systems, but IMO anything up to a
modest-sized company does not require that much horsepower.
My file servers host 48T (6 + 2 x 8T) RAID6 arrays managed by
mdadm. They are not partitioned at any level. All of the RAID1 boot
systems are also managed by mdadm, as well as any Linux-only
workstations. Any workstation that has to boot Windows at any time
employs a harware RAID system like the LSI MegaRAID 9266. Obviously, my
systems employ relatively low-cost solutions, but they work well for my
purposes. Despite being economical, the servers can and do still
deliver more than 3Gbps across the LAN.
Example:
RAID-Server:/usr/local/sbin# cat /proc/mdstat
Personalities : [raid1] [raid6] [raid5] [raid4]
md0 : active raid6 sde[8] sdi[14] sdj[15] sdf[9] sdc[10] sdd[12] sdg[11]
sdh[13]
29301835776 blocks super 1.2 level 6, 1024k chunk, algorithm 2
[8/8] [UUUUUUUU]
bitmap: 0/37 pages [0KB], 65536KB chunk
md2 : active raid1 sda2[0] sdb2[1]
112239616 blocks super 1.2 [2/2] [UU]
bitmap: 1/1 pages [4KB], 65536KB chunk
md1 : active raid1 sdb1[2] sda1[0]
96128 blocks super 1.2 [2/2] [UU]
md3 : active raid1 sdb3[2] sda3[0]
12623872 blocks super 1.2 [2/2] [UU]
On 4/8/2019 5:33 AM, Paul Menzel wrote:
Dear Linux folks,
Can you share your experiences, which processors you choose for
your RAID6 systems? I am particularly interested in Intel
alternatives? Are AMD EPYC processors good alternatives for file
servers? What about ARM and POWER?
We currently use the HBA Adaptec Smart Storage PQI 12G SAS/PCIe 3
(rev 01), Dell systems and rotating disks.
For example, Dell PowerEdge R730 with 40x E5-2687W v3 @ 3.10GHz,
192 GB of memory, Linux 4.14.87 and XFS file system. (The processor
looks too powerful for the system. At least the processor usage
is at most at one or two thread.)
```
[ 0.394710] raid6: sse2x1 gen() 11441 MB/s
[ 0.416710] raid6: sse2x1 xor() 8099 MB/s
[ 0.438713] raid6: sse2x2 gen() 13359 MB/s
[ 0.460710] raid6: sse2x2 xor() 8910 MB/s
[ 0.482712] raid6: sse2x4 gen() 16128 MB/s
[ 0.504710] raid6: sse2x4 xor() 10009 MB/s
[ 0.526710] raid6: avx2x1 gen() 22242 MB/s
[ 0.548709] raid6: avx2x1 xor() 15406 MB/s
[ 0.570710] raid6: avx2x2 gen() 25699 MB/s
[ 0.592710] raid6: avx2x2 xor() 16521 MB/s
[ 0.614709] raid6: avx2x4 gen() 29847 MB/s
[ 0.636710] raid6: avx2x4 xor() 18617 MB/s
[ 0.642001] raid6: using algorithm avx2x4 gen() 29847 MB/s
[ 0.648000] raid6: .... xor() 18617 MB/s, rmw enabled
[ 0.654001] raid6: using avx2x2 recovery algorithm
```
```
$ more /proc/mdstat
Personalities : [linear] [raid0] [raid1] [raid6] [raid5] [raid4] [multipath]
md1 : active raid6 sds[0] sdah[15] sdag[14] sdaf[13] sdae[12] sdad[11] sdac[10] sdab[9] sdaa[8] sdz[7] sdy[6] sdx[5] sdw[4] sdv[3] sdu[2] sdt[1]
109394518016 blocks super 1.2 level 6, 512k chunk, algorithm 2 [16/16] [UUUUUUUUUUUUUUUU]
bitmap: 0/59 pages [0KB], 65536KB chunk
md0 : active raid6 sdai[16] sdc[0] sdr[15] sdp[13] sdo[12] sdn[11] sdm[10] sdl[9] sdk[8] sdj[7] sdi[6] sdh[5] sdg[4] sdf[3] sde[2] sdd[1]
109394518016 blocks super 1.2 level 6, 512k chunk, algorithm 2 [16/16] [UUUUUUUUUUUUUUUU]
bitmap: 0/59 pages [0KB], 65536KB chunk
unused devices: <none>
```
Kind regards,
Paul
---
This email has been checked for viruses by Avast antivirus software.
https://www.avast.com/antivirus
