What we're talking about is the "simple" mirror option in OS X Server 10.2, which johnsonwax correctly points out to be not as easy as many would expect.
Picture this:
XServe (1) has 4 HD bays, all ATA 100 master drives. In bay 1 and 2 you place 120 GB IBM's HD, easily setup as a mirror. But, the drive in bay 2 gets some kind of default making you replace it by a new IBM 120 GB drive, exactly the same as the first two. Trouble now is repairing the mirror. It looks very simple using Disk Utility, but forget that. That doesn't work. You'll have to use the CLI, reading the documentation on Apple' site first, making the whole operation more time consuming, and more difficult than many would imagine.
Bottom line; yes, it works. But more trouble than you would expect.
Can the Xserve be setup with a hot-spare so that it will autmotically fix itself when there are problems?
What we're talking about is the "simple" mirror option in OS X Server 10.2, which johnsonwax correctly points out to be not as easy as many would expect.
Picture this:
XServe (1) has 4 HD bays, all ATA 100 master drives. In bay 1 and 2 you place 120 GB IBM's HD, easily setup as a mirror. But, the drive in bay 2 gets some kind of default making you replace it by a new IBM 120 GB drive, exactly the same as the first two. Trouble now is repairing the mirror. It looks very simple using Disk Utility, but forget that. That doesn't work. You'll have to use the CLI, reading the documentation on Apple' site first, making the whole operation more time consuming, and more difficult than many would imagine.
Bottom line; yes, it works. But more trouble than you would expect.
Yeah, I have my boot volume mirrored which required me to boot off of another device and rebuild the set. Took about 3 hours.
Now, mirroring your boot volume isn't ideal, by any means, and so I don't really criticize the need to boot off of an external volume, but 4 hours to rebuild a 120GB drive?!
Anyway, my understanding is that the RAID software in OS X Server is, well, not well written but should be in much better shape come 10.3.
Can the Xserve be setup with a hot-spare so that it will autmotically fix itself when there are problems?
Yeah, the Xserve RAID can, and the Xserve can IP failover pretty trivially, so if you can swing a full hot-spare server, you'll be in good shape that way. Apple knows what their weakenesses are and are working on them.
if apple thought that SCSI drives are the way to go, they would have made the XRAID SCSI instead of ATA.
Instead, they went ATA and judged that it would be more suitable for most of the market.
I'm not doubting that there are some people who need the performance of 15k SCSI etc.
I don't know of any server senario for that, however. The Power Mac is Apple's semi-workstation Mac. Disk intensive/mission critical servers can use the Xserve RAID.
That's where Tom Waits got it from, obviously. I just tried to joke because the only connection between Black Rider and Smeagol transposed onto Apple's products means that if Smeagol is Mac OS 10.2.7, then Black Rider is G5. Ain't sure.
<Edit>By the way, are there black panthers?
Actually, you're not even close. The Black Rider was a German stage musical (by Robert Wilson) that Tom Waits wrote and performed the music for.
Trouble now is repairing the mirror. It looks very simple using Disk Utility, but forget that. That doesn't work. You'll have to use the CLI, reading the documentation on Apple' site first, making the whole operation more time consuming, and more difficult than many would imagine.
Bottom line; yes, it works. But more trouble than you would expect.
I know little about servers, so this may be an incredibly stupid question, but....
Why not rebuild the new drive using Carbon Copy Cloner? It would only be a few clicks and it would take maybe 15 minutes or so.
Actually, you're not even close. The Black Rider was a German stage musical (by Robert Wilson) that Tom Waits wrote and performed the music for.
"Come on in
It ain't no sin
to take off your skin
and rattle around in your bones.
Come along with the Black Rider
We'll have a gay old time."
I think the Black Rider might have been Satan in the play--but I'm not sure. But see, it could be a sign that Mac is moveing to Intel. \ Or maybe not. I still like the song.
Good servers have the ability to hot swap and rebuild drives. That is, the drive breaks, you hot swap it with a good drive and the server automatically rebuilds all the data to the good drive using the redundant data in the RAID.
If you're lucky, the server will pick up that the drive is failing through S.M.A.R.T., and you can replace the drive before it dies completely.
Because the data in a server is generally frequently changing, CCC is ineffective. You want the data from right now to be rebuilt, not the data from yesterday.
Also, even if the data wasn't changing, CCC takes a long time. You would be wiping all the drives in an array, and replacing all the data on them when using CCC.
CCC = Great for clients, not for the kind of servers we're talking about.
Comments
Originally posted by MacsRgr8
What we're talking about is the "simple" mirror option in OS X Server 10.2, which johnsonwax correctly points out to be not as easy as many would expect.
Picture this:
XServe (1) has 4 HD bays, all ATA 100 master drives. In bay 1 and 2 you place 120 GB IBM's HD, easily setup as a mirror. But, the drive in bay 2 gets some kind of default making you replace it by a new IBM 120 GB drive, exactly the same as the first two. Trouble now is repairing the mirror. It looks very simple using Disk Utility, but forget that. That doesn't work. You'll have to use the CLI, reading the documentation on Apple' site first, making the whole operation more time consuming, and more difficult than many would imagine.
Bottom line; yes, it works. But more trouble than you would expect.
Can the Xserve be setup with a hot-spare so that it will autmotically fix itself when there are problems?
Originally posted by Mike
Can the Xserve be setup with a hot-spare so that it will autmotically fix itself when there are problems?
No, but the Xserve RAID can.
Originally posted by Barto
No, but the Xserve RAID can.
Are you using one? Is it in a switched environment?
Originally posted by MacsRgr8
What we're talking about is the "simple" mirror option in OS X Server 10.2, which johnsonwax correctly points out to be not as easy as many would expect.
Picture this:
XServe (1) has 4 HD bays, all ATA 100 master drives. In bay 1 and 2 you place 120 GB IBM's HD, easily setup as a mirror. But, the drive in bay 2 gets some kind of default making you replace it by a new IBM 120 GB drive, exactly the same as the first two. Trouble now is repairing the mirror. It looks very simple using Disk Utility, but forget that. That doesn't work. You'll have to use the CLI, reading the documentation on Apple' site first, making the whole operation more time consuming, and more difficult than many would imagine.
Bottom line; yes, it works. But more trouble than you would expect.
Yeah, I have my boot volume mirrored which required me to boot off of another device and rebuild the set. Took about 3 hours.
Now, mirroring your boot volume isn't ideal, by any means, and so I don't really criticize the need to boot off of an external volume, but 4 hours to rebuild a 120GB drive?!
Anyway, my understanding is that the RAID software in OS X Server is, well, not well written but should be in much better shape come 10.3.
Originally posted by Mike
Can the Xserve be setup with a hot-spare so that it will autmotically fix itself when there are problems?
Yeah, the Xserve RAID can, and the Xserve can IP failover pretty trivially, so if you can swing a full hot-spare server, you'll be in good shape that way. Apple knows what their weakenesses are and are working on them.
Originally posted by AirSluf
The short answer seems to be no!
Maybe these guys know something about
Smeagol and the Blackriders
www.lordsoftherhymes.com
On the whole
SCSI vs ATA debate
if apple thought that SCSI drives are the way to go, they would have made the XRAID SCSI instead of ATA.
Originally posted by newkleus
if apple thought that SCSI drives are the way to go, they would have made the XRAID SCSI instead of ATA.
Instead, they went ATA and judged that it would be more suitable for most of the market.
I'm not doubting that there are some people who need the performance of 15k SCSI etc.
I don't know of any server senario for that, however. The Power Mac is Apple's semi-workstation Mac. Disk intensive/mission critical servers can use the Xserve RAID.
Barto
Originally posted by costique
That's where Tom Waits got it from, obviously. I just tried to joke because the only connection between Black Rider and Smeagol transposed onto Apple's products means that if Smeagol is Mac OS 10.2.7, then Black Rider is G5. Ain't sure.
<Edit>By the way, are there black panthers?
Actually, you're not even close. The Black Rider was a German stage musical (by Robert Wilson) that Tom Waits wrote and performed the music for.
Trouble now is repairing the mirror. It looks very simple using Disk Utility, but forget that. That doesn't work. You'll have to use the CLI, reading the documentation on Apple' site first, making the whole operation more time consuming, and more difficult than many would imagine.
Bottom line; yes, it works. But more trouble than you would expect.
I know little about servers, so this may be an incredibly stupid question, but....
Why not rebuild the new drive using Carbon Copy Cloner? It would only be a few clicks and it would take maybe 15 minutes or so.
Carbon Copy Cloner.
Originally posted by Akumulator
Actually, you're not even close. The Black Rider was a German stage musical (by Robert Wilson) that Tom Waits wrote and performed the music for.
"Come on in
It ain't no sin
to take off your skin
and rattle around in your bones.
Come along with the Black Rider
We'll have a gay old time."
I think the Black Rider might have been Satan in the play--but I'm not sure. But see, it could be a sign that Mac is moveing to Intel.
Originally posted by Junkyard Dawg
I know little about servers
Obviously
Good servers have the ability to hot swap and rebuild drives. That is, the drive breaks, you hot swap it with a good drive and the server automatically rebuilds all the data to the good drive using the redundant data in the RAID.
If you're lucky, the server will pick up that the drive is failing through S.M.A.R.T., and you can replace the drive before it dies completely.
Because the data in a server is generally frequently changing, CCC is ineffective. You want the data from right now to be rebuilt, not the data from yesterday.
Also, even if the data wasn't changing, CCC takes a long time. You would be wiping all the drives in an array, and replacing all the data on them when using CCC.
CCC = Great for clients, not for the kind of servers we're talking about.
Barto