Re: Is shrinking raid5 possible?

2006-06-23 Thread Henrik Holst
Neil Brown wrote: In short, reducing a raid5 to a particular size isn't something that really makes sense to me. Reducing the amount of each device that is used does - though I would much more expect people to want to increase that size. Think about the poor people! :-) Those who can't

Re: Large single raid and XFS or two small ones and EXT3?

2006-06-23 Thread PFC
- XFS is faster and fragments less, but make sure you have a good UPS - ReiserFS 3.6 is mature and fast, too, you might consider it - ext3 is slow if you have many files in one directory, but has more mature tools (resize, recovery etc) I'd go with XFS or Reiser.

Re: Large single raid and XFS or two small ones and EXT3?

2006-06-23 Thread Francois Barre
2006/6/23, PFC [EMAIL PROTECTED]: - XFS is faster and fragments less, but make sure you have a good UPS Why a good UPS ? XFS has a good strong journal, I never had an issue with it yet... And believe me, I did have some dirty things happening here... - ReiserFS 3.6 is mature

Re: Large single raid and XFS or two small ones and EXT3?

2006-06-23 Thread Gordon Henderson
On Fri, 23 Jun 2006, Chris Allen wrote: Strange that whatever the filesystem you get equal numbers of people saying that they have never lost a single byte to those who have had horrible corruption and would never touch it again. We stopped using XFS about a year ago because we were getting

Re: Large single raid and XFS or two small ones and EXT3?

2006-06-23 Thread Francois Barre
Strange that whatever the filesystem you get equal numbers of people saying that they have never lost a single byte to those who have had horrible corruption and would never touch it again. [...] Loosing data is worse than loosing anything else. You can buy you another hard drive, you can buy

Re: Large single raid and XFS or two small ones and EXT3?

2006-06-23 Thread Al Boldi
Chris Allen wrote: Francois Barre wrote: 2006/6/23, PFC [EMAIL PROTECTED]: - XFS is faster and fragments less, but make sure you have a good UPS Why a good UPS ? XFS has a good strong journal, I never had an issue with it yet... And believe me, I did have some dirty things

Re: Large single raid and XFS or two small ones and EXT3?

2006-06-23 Thread Martin Schröder
2006/6/23, Francois Barre [EMAIL PROTECTED]: Loosing data is worse than loosing anything else. You can buy you That's why RAID is no excuse for backups. Best Martin - To unsubscribe from this list: send the line unsubscribe linux-raid in the body of a message to [EMAIL PROTECTED] More

Re: Large single raid and XFS or two small ones and EXT3?

2006-06-23 Thread Francois Barre
That's why RAID is no excuse for backups. Of course yes, but... (I'm working in car industry) Raid is your active (if not pro-active) security system, like a car ESP ; if something goes wrong, it gracefully and automagically re-align to the *safe way*. Whereas backup is your airbag. It's always

Re: Large single raid and XFS or two small ones and EXT3?

2006-06-23 Thread Chris Allen
Martin Schröder wrote: 2006/6/23, Francois Barre [EMAIL PROTECTED]: Loosing data is worse than loosing anything else. You can buy you That's why RAID is no excuse for backups. We have 50TB stored data now and maybe 250TB this time next year. We mirror the most recent 20TB to a secondary

Re: Large single raid and XFS or two small ones and EXT3?

2006-06-23 Thread Bill Davidsen
Martin Schröder wrote: 2006/6/23, Francois Barre [EMAIL PROTECTED]: Loosing data is worse than loosing anything else. You can buy you That's why RAID is no excuse for backups. The problem is that there is no cost effective backup available. When a tape was the same size as a disk and

Re: Large single raid and XFS or two small ones and EXT3?

2006-06-23 Thread Francois Barre
The problem is that there is no cost effective backup available. One-liner questions : - How does Google make backups ? - Aren't tapes dead yet ? - What about a NUMA principle applied to storage ? - To unsubscribe from this list: send the line unsubscribe linux-raid in the body of a message to

Re: Large single raid and XFS or two small ones and EXT3?

2006-06-23 Thread Andreas Dilger
On Jun 23, 2006 17:01 +0300, Al Boldi wrote: Chris Allen wrote: Francois Barre wrote: 2006/6/23, PFC [EMAIL PROTECTED]: - ext3 is slow if you have many files in one directory, but has more mature tools (resize, recovery etc) Please use mke2fs -O dir_index or tune2fs -O

Re: Large single raid and XFS or two small ones and EXT3?

2006-06-23 Thread Russell Cattelan
Al Boldi wrote: Chris Allen wrote: Francois Barre wrote: 2006/6/23, PFC [EMAIL PROTECTED]: - XFS is faster and fragments less, but make sure you have a good UPS Why a good UPS ? XFS has a good strong journal, I never had an issue with it yet... And believe me,

Re: Large single raid and XFS or two small ones and EXT3?

2006-06-23 Thread Christian Pedaschus
Andreas Dilger wrote: On Jun 23, 2006 17:01 +0300, Al Boldi wrote: Chris Allen wrote: Francois Barre wrote: 2006/6/23, PFC [EMAIL PROTECTED]: - ext3 is slow if you have many files in one directory, but has more mature tools (resize, recovery etc)

Re: Large single raid and XFS or two small ones and EXT3?

2006-06-23 Thread Christian Pedaschus
Christian Pedaschus wrote: for ext3 use (on unmounted disks): tune2fs -O has_journal -o journal_data /dev/{disk} tune2fs -O dir_index /dev/{disk} if data is on the drive, you need to run a fsck afterwards and it uses a good bit of ram, but it makes ext3 a good bit faster. and my main points

Re: Is shrinking raid5 possible?

2006-06-23 Thread Christian Pernegger
Why would you ever want to reduce the size of a raid5 in this way? A feature that would have been useful to me a few times is the ability to shrink an array by whole disks. Example: 8x 300 GB disks - 2100 GB raw capacity shrink file system, remove 2 disks = 6x 300 GB disks -- 1500 GB raw

Re: Large single raid and XFS or two small ones and EXT3?

2006-06-23 Thread Tom Vier
On Fri, Jun 23, 2006 at 11:21:34AM -0500, Russell Cattelan wrote: When you refer to data=ordered are you taking about ext3 user data journaling? iirc, data=ordered just writes new data out before updating block pointers, the file's length in its inode, and the block usage bitmap. That way you

Re: [PATCH*2] mdadm works with uClibc from SVN

2006-06-23 Thread Nix
On Fri, 23 Jun 2006, Neil Brown mused: On Friday June 23, [EMAIL PROTECTED] wrote: On 20 Jun 2006, [EMAIL PROTECTED] prattled cheerily: For some time, mdadm's been dumping core on me in my uClibc-built initramfs. As you might imagine this is somewhat frustrating, not least since my root

Re: Large single raid and XFS or two small ones and EXT3?

2006-06-23 Thread Nix
On 23 Jun 2006, Francois Barre uttered the following: The problem is that there is no cost effective backup available. One-liner questions : - How does Google make backups ? Replication across huge numbers of cheap machines on a massively distributed filesystem. -- `NB: Anyone suggesting

Re: Large single raid and XFS or two small ones and EXT3?

2006-06-23 Thread Nix
On 23 Jun 2006, PFC suggested tentatively: - ext3 is slow if you have many files in one directory, but has more mature tools (resize, recovery etc) This is much less true if you turn on the dir_index feature. -- `NB: Anyone suggesting that we should say Tibibytes instead of

Re: Large single raid and XFS or two small ones and EXT3?

2006-06-23 Thread Nix
On 23 Jun 2006, Christian Pedaschus said: and my main points for using ext3 is still: it's a very mature fs, nobody will tell you such horrible storys about data-lossage with ext3 than with any other filesystem. Actually I can, but it required bad RAM *and* a broken disk controller *and* an

Re: Large single raid and XFS or two small ones and EXT3?

2006-06-23 Thread Neil Brown
On Friday June 23, [EMAIL PROTECTED] wrote: The problem is that there is no cost effective backup available. One-liner questions : - How does Google make backups ? No, Google ARE the backups :-) - Aren't tapes dead yet ? LTO-3 does 300Gig, and LTO-4 is planned. They may not cope with