[ale] XFS on Linux - Is it ready for prime time?

[Greg Freemyer]

Doug,

I just googled a bit and found one person that said a 10TB filesystem
required 20GB of ram to xfs_check.

In his case he setup a 20GB swap and it ran to completion (slowly).

Subsequent xfs_check runs "only" used 2.5 GB of ram.

fyi: I think I've read posts where the xfs team is working on a fix
for the huge ram issue.  Who knows, maybe its fixed and we're running
old tools.

fyi2: since your doing a real NAS

The latest advice for fsck style checks on the ext4 list is to use LVM
to manage your volumes.  Then make a snapshot routinely and run fsck
style tools against the snapshot to look for corruption.

if and only if they find corruption should you unmount the volume and
run a fsck, etc. against the live volume.

The above allows corruption to be found early without imposing lots of
downtime on the user.

Greg

On Thu, Apr 22, 2010 at 7:14 AM, Greg Freemyer <greg.freemyer at gmail.com> wrote:
> iirc
>
> Xfs_check uses ram linearly to your filesystem size.
>
> If your building 10TB filesystem, you need a large amount of ram for xfs_check.
>
> I don't recall the ratio, but its well known.
>
> Greg
>
>
>
> On 4/21/10, Doug McNash <dmcnash at charter.net> wrote:
>>
>> I'm consulting at a company that wants to turn their Linux based NAS in to a
>> reliable product.  They initially chose XFS because they were under the
>> impression that it was high performance but what they got was something of
>> questionable reliability. I have identified and patched several serious bugs
>> (2.6.29) and I have a feeling there are more unidentified ones out there.
>> Furthermore, xfs_check craps out of memory every time so we have to do an
>> xfs_repair at boot and it takes forever.  But today we got into a situation
>> where xfs_repair can't repair the disk (a raid5 array btw).
>>
>> Does anyone out there use xfs? How about a suggestion for a stable
>> replacement.
>> --
>> doug mcnash
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> --
> Sent from my mobile device
>
> Greg Freemyer
> Head of EDD Tape Extraction and Processing team
> Litigation Triage Solutions Specialist
> http://www.linkedin.com/in/gregfreemyer
> CNN/TruTV Aired Forensic Imaging Demo -
>   http://insession.blogs.cnn.com/2010/03/23/how-computer-evidence-gets-retrieved/
>
> The Norcross Group
> The Intersection of Evidence & Technology
> http://www.norcrossgroup.com
>



-- 
Greg Freemyer
Head of EDD Tape Extraction and Processing team
Litigation Triage Solutions Specialist
http://www.linkedin.com/in/gregfreemyer
CNN/TruTV Aired Forensic Imaging Demo -
   http://insession.blogs.cnn.com/2010/03/23/how-computer-evidence-gets-retrieved/

The Norcross Group
The Intersection of Evidence & Technology
http://www.norcrossgroup.com