RAID 1 failure

[stek]

On a recent new build, I tried RAID1 with two new 1 TB Drives. I couldnt believe how god damn slow it was. I think it was something like RAID 1 = 55 Mb a second, a single drive, 110 Mb a second, RAID 0 180 Mb.

Needless to say I wiped and reinstalled with RAID 0.

You do know that losing one disk will mean all your data is gone?

[malvolio]

You do know that losing one disk will mean all your data is gone?

The idea is to use RAID 0+1, then you get both double the read speed and full redundancy with only a slight write overhead.

HTH

[escapeUK]

You do know that losing one disk will mean all your data is gone?

Of course I do. Its backed up. The speed is more important to me, and the odds of a drive failing are quite slim. I think in my life I have had more cars fail than hard drives.

With real RAID 1, you should also get double the speed. You do with Adaptec cards anyway as they read from both drives at the same time. Pretend RAID 1 built into motherboards doesnt seem to does this.

[lilelvis2000]

I backup my RAID 5 to a RAID 1 - both use software RAID which I find acceptable as I'm not transferring gigabytes.

The advantage of software RAID is I'm not tied into the proprietary encodings with the hardware ones use. For example..I can take one drive out of my RAID 1 and pop it into another machine, mount it and read it. I've tried it, it does work.

The only problem I have, well really two, is that first. Its hard for me to figure out which drive failed. I have to look at the serial numbers. Second, I hear the whole RAID remove drive-add drive procedure in LINUX can - uhhh - not work sometimes.

[stek]

Of course I do. Its backed up. The speed is more important to me, and the odds of a drive failing are quite slim. I think in my life I have had more cars fail than hard drives.

With real RAID 1, you should also get double the speed. You do with Adaptec cards anyway as they read from both drives at the same time. Pretend RAID 1 built into motherboards doesnt seem to does this.

Sorry, didn't want to insult your intelligence!

I like the U320 SCSI in my IBM pSeries AIX Intellistation, the disk can be rattling away like a machine gun and box just feels as alive as normal desktop wise. Even as a Mac head, just doing a simple bit of file copying on his recent iMac causes desktop slowdown.

[stek]

I backup my RAID 5 to a RAID 1 - both use software RAID which I find acceptable as I'm not transferring gigabytes.

The advantage of software RAID is I'm not tied into the proprietary encodings with the hardware ones use. For example..I can take one drive out of my RAID 1 and pop it into another machine, mount it and read it. I've tried it, it does work.

The only problem I have, well really two, is that first. Its hard for me to figure out which drive failed. I have to look at the serial numbers. Second, I hear the whole RAID remove drive-add drive procedure in LINUX can - uhhh - not work sometimes.

I've got an IBM POWER3 box here - two internal disks and a six disk array with a raid adapter, apparently it can do RAID5+1, I'm going to give it a bit of remove-add of a disk, after I've set it up...

[escapeUK]

Sorry, didn't want to insult your intelligence!

I like the U320 SCSI in my IBM pSeries AIX Intellistation, the disk can be rattling away like a machine gun and box just feels as alive as normal desktop wise. Even as a Mac head, just doing a simple bit of file copying on his recent iMac causes desktop slowdown.

Be interesting to know the speed of it, HD Tach?

Mine is as follows:-

Quick Bench
Average read: 216.8 Mb/s
Burst speed: 392 Mb/s
Random Access: 14.4 Ms

Thats from 2 x 1 Tb F4 Drives in Raid 0

Long Bench
Average read: 225.9 Mb/s
Burst speed: 387.9 Mb/s
Random Access: 14.8 Ms

[VectraMan]

Second, I hear the whole RAID remove drive-add drive procedure in LINUX can - uhhh - not work sometimes.

I couldn't get Linux working at all with my "pretend" RAID setup.

[Sysman]

I like the U320 SCSI in my IBM pSeries AIX Intellistation, the disk can be rattling away like a machine gun and box just feels as alive as normal desktop wise. Even as a Mac head, just doing a simple bit of file copying on his recent iMac causes desktop slowdown.

Several years ago I was converting a bunch of AIFF files to MP3 and found that my VMS Alpha system running on a U320 SCSI was about 3 times the speed of my iBook running on a Firewire 400 drive. Same version of same program, same CPU clock speed on both systems, and as near as makes no difference same CPU consumed on both platforms.

Everything else on the Mac slowed to a crawl, but on the VMS box, the desktop felt just as snappy as on an empty system. At the time my conclusion was that VMS has a better process scheduler. I suspect you are seeing the same with AIX.

With a pile of CDs to get onto my iPod, it was a no brainer which system I used for the MP3 conversion.

[lilelvis2000]

I couldn't get Linux working at all with my "pretend" RAID setup.

I've got two currently and am planning on building another. I've got a LVM with six partitions sitting on top of the RAID 5 as well. What went wrong in your case?