Re: Poor raid 1 performance?
Bruce T. Berger wrote:
"Mark" <pleasenospam@xxxxxxxxxx> wrote in message
news:uxxjf.8197$ea6.3967@xxxxxxxxxxxxxxxxxxxxxxxxxxxxx
Hi there,
I am planning on building a new computer system. Given the current cheap
price and massive capacity of hard drives, I am thinking of using a raid
array.
To me, raid 1 seems the ideal solution. Raid 1 greatly improves data
security, which is very important to me (and why I would never go with
raid 0). Theoretically, the performance of raid 1 should also be what I
want. Reads can be split across the two drives, leading to greater read
performance, while write performance might be slower. Given the way I use
the computer, read performance will help when it boots up, loads
applications, loads games, etc. On the other hand, the poorer write
performance will be less of an issue as much less is written to the disk
during typical use, and I tend to just leave the computer when installing
new programs (when large amounts of information does need to be written to
the disk).
Despite raid 1 seeming to be ideal, the read performance on current
motherboard raid chipsets shows little to no improvement compared to that
of a single drive:
http://techreport.com/reviews/2004q2/chipset-raid/index.x?pg=1
Is it possible to get improved read performance using raid 1??
No! Raid 1 exists solely for data preservation ...you may be thinking of
RAID 1+0 which will give you redundancy plus a performance gain without
requiring a RAID 5 capable controller but as far as RAID 1 is concerned you
are mistaken in your belief that it will or should boost performance.
btb
It is certainly possible with RAID1 to get better read throughput than
with a single HD, since RAID1 has twice as many on-disk read channels and
twice as many seek mechanisms. But, any increased read performance depends
on the workload (to have multiple reads outstanding) and on the RAID driver
(to not serialize the multiple outstanding reads).
I do agree that the primary reason for deploying RAID1 is data integrity
rather than performance, but modest performance gains have certainly been
measured (by me and by others) with good RAID1 implementations.
--
Cheers, Bob
.
Relevant Pages
- Re: RAIDING different size drives
... You dont need to restore specific parts on a hard drive failure with the OS not mirrored. ... it being too easy to delete your good mirror by making it part of a new raid, ... But people *do* use it by mistake, thinking they are doing a proper backup. ... with a Win live CD to get a look at the state of the hard drives when deciding what has died etc. ...
(comp.sys.ibm.pc.hardware.storage) - Re: RAID vs. non-RAID?
... > RAID 0 splits the system on two physical hard drives. ... > RAID 1 backs up the first hard drive to the second one. ... Mirroring is *not* suitable for using as backup. ...
(microsoft.public.windowsxp.newusers) - Re: Raid problem?
... I have a server that I support that I ... the two hard drives be configured with raid (all data stored ... It says all hard drives OK. ... Device Port Location: Internal ...
(microsoft.public.windows.server.sbs) - Help! Repairing a RAID 1 dynamic disk
... Its a Dell Windows 2000 server with two SCSI hard drives running ... The two drives are configured with dynamic disk and software RAID ... The disk 0's C:OS partition is no longer synced to the disk 1's ...
(microsoft.public.windows.server.general) - Help! Repairing a RAID 1 dynamic disk
... Its a Dell Windows 2000 server with two SCSI hard drives running ... The two drives are configured with dynamic disk and software RAID ... The disk 0's C:OS partition is no longer synced to the disk 1's ...
(microsoft.public.windows.server.sbs) |
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